An investigation of the electron density of a Jahn-Teller-distorted Cr^II cation: the crystal structure and charge density of hexa­kis­(aceto­nitrile-[kappa]N)chromium(II) bis­(tetra­phenyl­borate) aceto­nitrile disolvate

In the crystal structure of the title homoleptic Cr^II complex, [Cr(CH₃CN)₆](C₂₄H₂₀B)₂·CH₃CN, the [Cr(CH₃CN)₆]²⁺ cation is a high-spin d⁴ complex with strong static, rather than dynamic, Jahn-Teller distortion. The electron density of the cation was determined by single-crystal X-ray refinements using aspherical structure factors from wavefunction calculations. The detailed picture of the electronic density allowed us to assess the extent and directionality of the Jahn-Teller distortion of the Cr^II cation away from idealized octahedral symmetry. The topological analysis of the aspherical d-electron density about the Cr^II cation showed that there are significant valence charge concentrations along the axial Cr-N axes. Likewise, there were significant valence charge depletions about the Cr^II cation along the equatorial Cr-N bonds. These charge concentrations are in accordance with a Jahn-Teller-distorted six-coordinate complex.

S1. Introduction

Homoleptic o­cta­hedral compounds of Cr^II are invaluable synthons in the coordination chemistry of chromium. However, despite their synthetic utility, very few examples have been crystallographically characterized. Such compounds are also inter­esting from a fundamental perspective, as they have partially filled d orbitals in a degenerate ground state. The Jahn–Teller effect distorts the nuclei from o­cta­hedral symmetry to remove the orbital degeneracy. The distortion can in principle lie anywhere along the Jahn–Teller minimum potential energy surface, the so-called `Mexican hat diagram' and the Jahn–Teller distortion is usually fluxional (Falvello, 1997). However, in the crystal structures of related six-coordinate Cr²⁺ (high-spin) and Cu²⁺ compounds, they usually distort by elongation of a single pair of metal–ligand bonds [see, for example, Figgis et al. (1990, 2000)]. In the environment of a rigid solid, inter­change between different elongations along the molecular x, y and z axes involves breaking the bonds which hold the ligand molecules (hydrogen bonds etc.) in the crystal structure. Jahn–Teller distortions are a challenge for molecular modelling since they are essentially dynamic in nature. Since o­cta­hedral systems involve minimal steric repulsion about ligand atoms with maximal symmetry it is difficult or impossible to determine a priori in which direction the distortion will occur. We report the structure and electron density (ED) of [Cr(CH₃CN)₆](BPh₄)₂·CH₃CN, (I), a compound representing a rare well ordered Jahn–Teller-distorted Cr^II species. A detailed picture of the electronic structure allows us to assess the extent and directionality of the Jahn–Teller distortion away from idealized o­cta­hedral symmetry and observe the influence on the bonding with ligand N atoms. Examinations of the electronic structure at the Jahn–Teller minimum also provide detailed insights into the electronic structure of synthetically valuable homoleptic six-coordinate Cr^II species. To study the title compound in more detail than possible with the conventional independent atom model (IAM), we have carried out a combined X-ray diffraction study (XD) with free refinement of the multipoles and a computational study where we have projected (Dittrich et al., 2005) the theoretical ED from a wavefunction onto the multipole model (Hansen & Coppens, 1978). The resulting scattering factors were fixed in the least-squares refinement. An advantage of this approach is that it gives a complete static distribution of the ED that can be compared directly with densities from the free multipolar refinement. Both sets of multipole populations were evaluated to give d-orbital populations (Holladay et al., 1983).

S2. Experimental

S2.1. Synthesis and crystallization

The title compound, [Cr(CH₃CN)₆](BPh₄)₂·CH₃CN, was synthesized inside a glove-box by combining CrCl₂ and NaBPh₄ in a scintillation vial and stirring overnight in anhydrous aceto­nitrile (10 ml). A white precipitate was allowed to settle, the pale-blue solution was filtered over a fine-porosity fritted glass funnel, and the remaining solid was rinsed with aceto­nitrile (5 ml). The clear pale-blue aceto­nitrile solution was concentrated in vacuo to one half of the original volume and stored at ambient temperature to afford single crystals of the title compound over a period of 4 d.

S2.2. Refinement

S2.2.1. Experimental multipole refinement

Crystal data, data collection and structure refinement details are summarized in Table 1. Data were measured at 110 K using ω scans using Mo Kα radiation (fine-focus sealed tube, 45 kV, 35 mA). The total number of runs and images was based on the strategy calculation from the program APEXII (Bruker, 2014), giving redundant and 100% complete diffraction data to 0.5 Å (2θ = 90°) and a highest resolution of 0.481 Å (2θ = 95°). Multipole refinements were initiated with the results from a SHELXL refinement (Sheldrick, 2008) and carried out with the XD2006 suite of programs (Volkov et al., 2006). Local coordinate systems were set for each atom and local site symmetry employed to restrict the number of multipoles to be refined, for example, chemically equivalent phenyl ring C and H atoms. However, chemical constraints were not used for the refinement of the [Cr(CH₃CN)₆]²⁺ cation, which resides on a crystallographic twofold axis. Hence, its x and z coordinates were fixed and the U₁₂ and U₂₃ tensor components were set to zero. The site symmetry also requires a particular choice of coordinate system and restricts which multipole populations are refined. For a site with site symmetry 2, the z axis must be parallel to the twofold axis and the multipole populations with indices (l, 2µ, ±) are refined (Koritsanszky et al., 2007; Table 2). The Su–Coppens–Macchi databank with relativistic Dirac–Fock wavefunctions for the core, valence and deformation density was used (Su & Coppens, 1998). The refinements with a 3d⁴ valence configuration gave a slightly better electron density (ED) than when a neutral-atom scattering factor for the Cr atom was used. The total charge of the asymmetric unit was constrained to be zero, allowing charge transfer between the molecules. All atomic positions, except H atoms, were refined freely. [H atoms fully refined in (2)?] The C—H distances were constrained to their neutron values (Allen & Bruno, 2010). Only reflections with intensities I > 3σ(I) were included in the refinement.

S2.2.2. Least-squares refinement with theoretically predicted aspherical scattering factors

A second refinement was performed using scattering factors derived from a theoretical B3LYP/TZVP ED of the isolated [Cr(CH₃CN)₆]²⁺ cation using the same starting structure. In this refinement, only the atomic positions and the anisotropic displacement parameters were adjusted. The experimental refinement data contained atomic positions, anisotropic displacement parameters and multipoles. Care was taken to preserve the local coordinate system (i.e. the chemical environment of the atom) and the overall charge constraints in both sets of refinements. The [Cr(CH₃CN)₆]²⁺ cation was assigned a dipositive charge. Charge transfer between molecules was only allowed in the experimental multipole refinement, leading to a slight discrepancy between monopole populations for the [Cr(CH₃CN)₆]²⁺ cation in the refinement with theoretical scattering factors (which sum to 2+). The program invariomtool (Hübschle et al., 2007) was used in setting the local coordinate system and preparing the master and input files for multipole refinement with the XDLSM program of the XD2006 suite (Farrugia, 2007; Volkov et al., 2006).

S2.2.3. Theoretical computations

Unrestricted density functional theory (DFT) calculations were carried out for [Cr(CH₃CN)₆] using the B3LYP functional (Becke, 1993; Lee et al., 1988) and a triple ζ valence (TZVP) basis set (Schäfer et al., 1994), as implemented in the GAUSSIAN09 suite of programs (Frisch et al., 2009). The molecule was assigned a pentet spin state and an overall charge of 2+ for the calculations. An integration grid having 99 radial shells and 590 angular points per shell was used during the numerical integrations. Calculations were carried out using 504 basis functions and 860 primitives, of which 36 basis functions (6 s, 12 p and 18 d functions) and 86 primitives were from the Cr basis. The molecular wavefunction was calculated for the nuclear configuration taken from the crystal structure but with C—H distances normalized to neutron values (Allen & Bruno, 2010). Topological analysis of the electron-density distribution (EDD) was carried out with the program AIMALL (Keith, 2013). The program TONTO (Jayatilaka & Grimwood, 2003) was used to project the EDD onto the multipole model. The Fourier transform of the electron densities placed in an artificial unit cell then gave simulated X-ray structure factors (Jayatilaka, 1994; Jayatilaka & Dittrich, 2008). The space group P2/n was chosen to mimic the crystallographic symmetry at the Cr²⁺ site, and the twofold axis inter­sects the cation at the Cr^II atom in both the experimental and artificial crystal structures. The unit cell was large and the fragments thus sufficiently far from each other to be non-inter­acting. The structure factors (a Fourier transform of the ED) were generated by TONTO up to a resolution of (sinθ)/λ = 1.15 Å^-1. The above procedure is analogous to the one used in invariom modeling (Dittrich et al., 2006, 2013), which has been recently extended to coordination compounds (Dittrich et al., 2015).

S3. Results and discussion

Results from the XD refinements with spherical atoms, denoted (1), with freely refined, denoted (2), and with predicted, denoted (3), multipolar parameters are shown in Table 3. The free multipolar refinement lowered R(F) from 0.047 to 0.035 and improved the goodness-of-fit from 1.71 to 1.15. The fixed multipolar parameters led to an R(F) value of 0.036 with a goodness-of-fit value of 1.12. Both sets of multipolar parameter significantly lowered the differences between the mean-square displacement amplitudes (DMSDA – the Hirshfeld test) along inter­atomic vectors (Rosenfield et al., 1978) compared with those from a spherical atom refinement. The refinement with the theoretical multipolar gave the best DMSDA's along the Cr—N bonds (Table 4). The r.m.s. deviation (0.053) of the final difference maps was the same for both sets of aspherical-atom refinements. The largest residual peak and hole (±0.46 e Å^-3) are greater in magnitude with predicted than with experimental scattering factors (±0.33 e Å^-3). The largest residuals occurred within 0.5 to 1 Å to the Cr atom. There are small but significant displacements in the C- and N-atom positions relative to those of the spherical atom refinements (about 0.005 Å) and these are similar for the two sets of aspherical-atom refinements, indicating better treatment of the electron distribution about the Cr atom than in the IAM refinement.

The asymmetric unit (half the formula given in Table 1) contains the [Cr(CH₃CN)₆]²⁺ cation, with the Cr^II atom in the special position (1/2, y, 1/4), and a [B(C₆H₅)₄]^- anion and an aceto­nitrile solvent molecule in general positions (Fig. 1). The Cr²⁺ cation is highly distorted: the four equatorial bonds [2.0665 (6) and 2.0904 (6) Å] are considerably shorter than the two axial bonds [2.4259 (8) Å]. The two axial nitrile angles (Cr—N—C) are bent (Tables 5 and 6). Inter­molecular C—H···π inter­actions occur between the aceto­nitrile H atoms and the aromatic rings of the [B(C₆H₅)₄]^- anion, and there are favorable inter­actions between the aceto­nitrile H atoms and the nitrile N atom. The stronger metal–ligand bonding in the equatorial plane constrains these angles towards linearity as this would minimize steric repulsion between ligands. The weakly bound axial atoms are further apart, and are freer to move when perturbed by inter­molecular forces.

This arrangement of ligands and the corresponding electronic inter­action between these ligands and the Cr atom is of inter­est in Jahn–Teller theory. Difference-density maps were calculated using the differences between the structure-factor amplitudes from the multipole and independent atom models. Fourier deformation density maps in the plane of equatorial ligands calculated for both aspherical-atom models are compared in Fig. 2. A representation of the three-dimensional deformation ED from theoretical multipolar parameters (which reveals the character of the chemical bonding) is shown in Fig. 3. The deformation density shows four lobes of positive ED (and four lobes of negative density along the Cr—N bonds). This shape corresponds to the shape of a d_x2–y2 orbital when the equatorial plane is the xy plane. The experimental ED distribution has a pronounced charge accumulation along an axis bis­ecting a pair of alternate trans N—Cr—N angles (N1—Cr—N1' and N3—Cr—N3') and a weakened positive density in the adjacent bis­ector (N1—Cr—N3 and N1'—Cr—N3'). The experimental ED is smeared due to thermal motion, especially close to the Cr nucleus. Both maps show similar dative N—Cr bonding, with the lone pairs of the N atoms migrating to the Cr^II cation. The degree of migration of charge from the N atoms to the metal ion is remarkably similar in both models, despite the assumption of full charge transfer for predicted multipoles. The residual density from both sets of aspherical-atom refinements in the same plane is shown in Fig. 4. Both maps show some aspherical density features not modelled by the multipolar models, with maximum peak heights of 0.44 (Fig. 4a) and 0.32 e Å^-3 (Fig. 4b).

As there is no disorder, the six ligands are the same and the Cr^II cation is in an electronic degenerate state, the title compound is an excellent candidate for the investigation of the Jahn–Teller effect by an analysis of the charge density. The d-orbital populations can be derived from the multipole populations (Holladay et al., 1983) for both aspherical atom refinements and we will discuss the results using the point of view of classic crystal field theory first. In a standard textbook description of electrostatic crystal field theory, the Cr atom would generally be described as having tetra­gonal distortion along the z axis. The z axis is defined to be the axial bond direction and the symmetry properties of the orbitals are referred to using the D_{4 h} point group (Huheey et al., 1993). In crystal field theory, the d_xy and d_yz orbitals are degenerate (e_g) and lowest in energy when the Cr atom has tetra­gonal (D_4h) symmetry. Crystal field theory predicts the highest energy orbital to be the d_x2–y2 orbital (b_1g) with the standard orientation of the axes. In (I), the Cr^II cation is located on a site with site symmetry 2 and the z axis must be parallel to the twofold axis. This z axis subtends the equatorial N—Cr—N bond angles, while the x axis is the axial bond direction. This reorientation of axes transforms the d_x2–y2 orbital to the orbital that subtends the x, y axes (i.e. the d_yz orbital). The d-orbital populations are presented in Table 7. The multipole analysis gives roughly equal populations for the d_x2–y2, d_xz, d_xy and d_z2 orbitals, but with far fewer electrons in the orbital directed towards the equatorial ligands (the d_yz orbital). One can conclude from the experimental data in Table 7 that the highest-energy orbital is the d_yz orbital (it is the lowest populated orbital and is directed towards the equatorial ligands) and that the d_z2 orbital is stabilized by Jahn–Teller distortion. The qualitative agreement between the orbital populations from the refinements with calculated structure factors from theory and from the experimental diffraction data is satisfactory. Both theory and experiment indicate a significant increase in energy of the d_yz orbital with respect to the other orbitals and that the remaining orbitals are similar in energy.

The classical crystal field description is next complemented by an atoms in molecules (AIM) analysis (Bader, 1990) of the EDD from the B3LYP/TZVP wavefunction. The electron densities at the bond critical point (BCP) ρ(r_bcp) for the metal–ligand and the ligand C—N bonds are shown in Table 8. BCP's occur roughly midway between the Cr and N nuclei. The equatorial Cr—N BCP's have nearly twice the ED of the axial Cr1—N2 bond, which is due to the Jahn–Teller effect. In organic compounds, the charge concentrations occur close to the midpoints of bonds and ρ(r_bcp) correlates well with the strength of the bond. The outer electrons of a transition metal are more diffuse and the location of the valence electrons is less certain. Therefore, the values of these ρ(r_bcp) are low compared with the bonds in the ligands (Table 8). Also, the values of \nabla²ρ(r) are positive. Thus, there is little accumulation of electrons along these bond paths. However, there is significant ligand-to-metal charge migration (Fig. 2) between the Cr and the ligand N atoms. This not only indicates a strong electrostatic inter­action but also significant electron-pair density between the Cr^II cation and its ligands (and the bond-order sum for these six bonds is close to 2.0). This result is entirely consistent with a bonding picture where vacant orbitals centered on the metal atom have the correct symmetry to overlap with occupied orbitals on the donor atoms.

Contour maps of the Laplacian [\nabla²(r)ρ(r)] are shown in Fig. 5. As in the deformation maps, the Laplacian shows the aspherical d-electron density about the Cr^II cation. The lobes of metal [electron?] density are directed between the ligands in the equatorial plane, and there is significant valence charge concentration about the Cr nucleus directed towards the two N atoms along the axial Cr—N axis. These are revealed as (3,+3) critical points of \nabla²(r)ρ(r) where the electron densities are at local maxima. There are four of these critical points in the equatorial plane and two along the axial Cr—N axis. The equatorial angle LCP—Cr—LCP is 90°, and the angle LCP—LCP—Cr is 45°. Moreover, there are four (3,-3) critical points of \nabla²(r)ρ(r), where the EDD is at a local minimum along the equatorial Cr—N bond paths. This topology corresponds to that expected for a high-spin d⁴ Cr²⁺ cation in a tetra­gonal field. It is clearly evident that this arrangement entails minimal electrostatic repulsion between the t_2g electrons centered on the Cr and the donor electrons on the ligand atoms, and also the Jahn–Teller distortion has stabilized the dz² electron in the e_g set.

S4. Conclusions

In this work, the electron density of an ordered Jahn–Teller complex was investigated. A sense of the accuracy of the computed and experimental electron densities was obtained from a comparison of two aspherical-atom models. The theoretical multipolar model significantly improved the structural model from spherical-atom refinements, as shown by the lower mean-square displacement amplitudes, the goodness-of-fit values and the R indices. The multipole analysis gave d-orbital populations in agreement with classical crystal field theory. The deformation maps and the Laplacian densities from IAM analysis provide a more detailed description and show the aspherical d-electron density to be in rough agreement with classical crystal field theory.

In conclusion, aspherical-atom modeling provides a significant improvement on the spherical-atom model. For traditional multipole refinements, data collected at even lower temperatures and higher resolution would be needed to vouchsafe the veracity of the theoretical models.

Computing details

Data collection: APEX2 v2014.1-1 (Bruker, 2014) for (1); APEX2 (Bruker, 2014) for (2), (3). Cell refinement: SAINT v8.34A (Bruker, 2013) for (1); SAINT(Bruker, 2014) for (2); SAINT (Bruker, 2014) for (3). Data reduction: SAINT v8.34A (Bruker, 2013) for (1); SAINT (Bruker, 2014) for (2), (3). Program(s) used to solve structure: SHELXS97 for (1); SHELXS97 (Sheldrick, 2008) for (2), (3). Program(s) used to refine structure: SHELXL (Sheldrick, 2008) for (1); XD2006 (Volkov et al., 2006) for (2), (3). Molecular graphics: XD2006 (Volkov et al., 2006), X-SEED (Barbour, 2001) and AIMALL (Keith, 2013) for (2), (3). Software used to prepare material for publication: SHELXL (Sheldrick, 2008) for (1); XD2006 (Volkov et al., 2006) and publCIF (Westrip, 2010) for (2), (3).

Figures

	Fig. 1. A plot of the [Cr(CH3CN)6]^2+ cation of (I) with its closely associated (B(Ph)4)2^- anion and CH3CN solvent molecule, showing the atom-numbering scheme. The view is along a direction nearly perpendicular to the equatorial plane. Displacement ellipsoids are drawn at the 50% probability level.
	Fig. 2. Deformation ED maps for the [Cr(CH3CN)6]^2+ cation in the plane of atoms Cr1, N1 and N3, as calculated (a) from the experimental multipolar refinements (2) and (b) from the refinements with the theoretically predicted (3) multipolar parameters. Red lines represent positive contours and blue lines negative contours. Contours are drawn at 0.1 e^- Å^-3 intervals.
	Fig. 3. Residual ED maps for the [Cr(CH3CN)6]^2+ cation in the plane of atoms Cr1, N1 and N3. Panel (a) was calculated from the model corresponding to the unconstrained refinements (2) and panel (b) was calculated from the model corresponding to the refinements with the constrained (3) multipolar parameters. Red lines represent positive contours and blue lines negative contours. Contours are drawn at 0.1 e^- Å^-3 intervals.
	Fig. 4. Positive and negative deformation density isosurfaces (0.01 e^- Å^-3) of the [Cr(CH3CN)6]^2+ cation from refinements with the predicted multipolar parameters. There are concentrations of charge corresponding to nitrogen lone-pair electrons. There are also concentrations of d-electrons between the equatorial ligands and towards the axial ligands, with depletions along the equatorial Cr—N bonds.
	Fig. 5. A contour plot of the Laplacian [(\nabla^2ρ(r))] (a) in the plane of the equatorial ligands and (b) in the plane of atoms Cr1, N1 and N2 belonging to the equatorial and axial ligands. Red lines represent negative and blue lines positive contours.

(1)

Crystal data

C12H18CrN6·2(C24H20B)·2(C2H3N)	F(000) = 2152
Mr = 1018.92	Dx = 1.183 Mg m^−3
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71073 Å
a = 18.8632 (3) Å	Cell parameters from 9787 reflections
b = 14.6756 (2) Å	θ = 2.6–47.0°
c = 20.7596 (3) Å	µ = 0.25 mm^−1
β = 95.230 (1)°	T = 110 K
V = 5722.93 (15) Å^3	Prism, green
Z = 4	0.37 × 0.34 × 0.18 mm

Data collection

Bruker APEX-II CCD diffractometer	26260 independent reflections
Radiation source: fine-focus sealed tube	14506 reflections with I > 2σ(I)
Graphite monochromator	θmax = 47.6°, θmin = 1.8°
φ and ω scans	h = −34→39
Absorption correction: multi-scan SADABS2012/1 (Bruker, 2012) was used for absorption correction. wR2(int) was 0.0831 before and 0.0669 after correction. The Ratio of minimum to maximum transmission is 0.7925. The λ/2 correction factor is 0.0015.	k = −29→30
Tmin = 0.594, Tmax = 0.749	l = −42→42
127361 measured reflections

Refinement

Refinement on F^2	0 restraints
Least-squares matrix: full	H atoms treated by a mixture of independent and constrained refinement
R[F^2 > 2σ(F^2)] = 0.055	w = 1/[σ^2(Fo^2) + (0.0567P)^2 + 1.2339P] where P = (Fo^2 + 2Fc^2)/3
wR(F^2) = 0.147	(Δ/σ)max = 0.007
S = 1.00	Δρmax = 0.60 e Å^−3
26260 reflections	Δρmin = −0.78 e Å^−3
395 parameters

Special details

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Cr1	0.5000	0.73355 (2)	0.2500	0.01640 (4)
N1	0.50959 (4)	0.63183 (5)	0.32082 (3)	0.01992 (11)
N3	0.50456 (4)	0.83129 (5)	0.32198 (4)	0.02043 (12)
C13	0.81869 (4)	0.38610 (5)	0.44096 (3)	0.01381 (10)
C7	0.71091 (4)	0.43579 (5)	0.35133 (3)	0.01434 (10)
C25	0.72388 (4)	0.52060 (5)	0.46146 (3)	0.01511 (10)
C19	0.82989 (4)	0.53866 (5)	0.38073 (3)	0.01469 (10)
N2	0.62917 (4)	0.73312 (6)	0.25873 (4)	0.02444 (13)
C14	0.83946 (4)	0.31192 (5)	0.40421 (4)	0.01765 (12)
C1	0.52280 (4)	0.57464 (5)	0.35739 (4)	0.01813 (12)
C30	0.69365 (4)	0.47063 (5)	0.50982 (4)	0.01677 (11)
C24	0.86456 (4)	0.60751 (5)	0.41895 (4)	0.01833 (12)
C18	0.84833 (4)	0.38859 (5)	0.50557 (4)	0.01767 (12)
C20	0.85517 (4)	0.52512 (6)	0.31975 (4)	0.01876 (12)
C3	0.68363 (4)	0.75396 (6)	0.28292 (4)	0.02033 (13)
C12	0.67617 (4)	0.35098 (5)	0.35367 (4)	0.01776 (12)
C8	0.68534 (4)	0.49354 (5)	0.30034 (4)	0.01801 (12)
C5	0.50666 (4)	0.87916 (5)	0.36561 (4)	0.01844 (12)
C15	0.88532 (5)	0.24403 (5)	0.43019 (5)	0.02284 (15)
C21	0.90975 (4)	0.57754 (7)	0.29757 (4)	0.02410 (15)
C23	0.91917 (4)	0.66079 (6)	0.39745 (5)	0.02318 (15)
C11	0.62105 (4)	0.32514 (6)	0.30788 (4)	0.02224 (14)
C9	0.63010 (4)	0.46870 (6)	0.25431 (4)	0.02218 (14)
H9	0.6145	0.5100	0.2207	0.027*
C29	0.65150 (4)	0.51110 (6)	0.55377 (4)	0.02108 (13)
C17	0.89389 (4)	0.32103 (6)	0.53242 (4)	0.02310 (14)
C2	0.53907 (5)	0.50189 (7)	0.40354 (4)	0.02463 (15)
H2A	0.5611	0.4511	0.3821	0.037*
H2B	0.4951	0.4810	0.4206	0.037*
H2C	0.5721	0.5244	0.4392	0.037*
B1	0.77067 (4)	0.47031 (5)	0.40855 (4)	0.01357 (11)
C26	0.70633 (5)	0.61363 (5)	0.45842 (4)	0.02233 (14)
H26	0.7237	0.6498	0.4253	0.027*
C10	0.59787 (4)	0.38383 (7)	0.25744 (4)	0.02399 (15)
H10	0.5608	0.3661	0.2259	0.029*
C16	0.91229 (5)	0.24770 (6)	0.49482 (5)	0.02551 (16)
H16	0.9427	0.2010	0.5130	0.031*
C22	0.94157 (5)	0.64660 (6)	0.33625 (5)	0.02556 (16)
H22	0.9780	0.6834	0.3210	0.031*
C6	0.50900 (5)	0.93856 (6)	0.42156 (4)	0.02116 (13)
H6A	0.4906	0.9988	0.4083	0.032*
H6B	0.5583	0.9444	0.4405	0.032*
H6C	0.4797	0.9126	0.4537	0.032*
C28	0.63725 (5)	0.60413 (6)	0.55074 (5)	0.02572 (16)
H28	0.6096	0.6322	0.5812	0.031*
N4	0.83715 (5)	0.54081 (7)	0.64758 (5)	0.03448 (19)
C4	0.75343 (5)	0.77978 (7)	0.31291 (5)	0.02819 (17)
H4A	0.7757	0.8227	0.2848	0.042*
H4B	0.7833	0.7253	0.3194	0.042*
H4C	0.7483	0.8087	0.3548	0.042*
C31	0.80675 (5)	0.47468 (7)	0.65530 (4)	0.02435 (15)
C27	0.66431 (5)	0.65515 (6)	0.50210 (5)	0.02820 (18)
H27	0.6542	0.7185	0.4986	0.034*
C32	0.76930 (5)	0.38963 (6)	0.66481 (4)	0.02645 (16)
H32A	0.7622	0.3567	0.6236	0.040*
H32B	0.7230	0.4029	0.6805	0.040*
H32C	0.7975	0.3521	0.6967	0.040*
H12	0.6909 (7)	0.3110 (9)	0.3892 (6)	0.023 (3)*
H30	0.7018 (7)	0.4056 (9)	0.5124 (6)	0.021 (3)*
H18	0.8372 (7)	0.4404 (9)	0.5318 (6)	0.024 (3)*
H14	0.8219 (7)	0.3082 (9)	0.3561 (6)	0.023 (3)*
H8	0.7074 (7)	0.5554 (8)	0.2974 (6)	0.019 (3)*
H24	0.8505 (7)	0.6196 (9)	0.4634 (6)	0.022 (3)*
H20	0.8329 (7)	0.4765 (9)	0.2920 (6)	0.024 (3)*
H17	0.9126 (8)	0.3259 (10)	0.5780 (7)	0.032 (3)*
H21	0.9250 (7)	0.5653 (9)	0.2561 (7)	0.025 (3)*
H23	0.9429 (8)	0.7090 (10)	0.4255 (7)	0.034 (4)*
H29	0.6343 (8)	0.4714 (9)	0.5883 (7)	0.030 (3)*
H11	0.5999 (8)	0.2657 (9)	0.3113 (7)	0.029 (3)*
H15	0.8995 (8)	0.1961 (10)	0.4035 (7)	0.031 (3)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cr1	0.01779 (7)	0.01403 (7)	0.01726 (7)	0.000	0.00093 (5)	0.000
N1	0.0201 (3)	0.0190 (3)	0.0204 (3)	0.0010 (2)	0.0009 (2)	0.0005 (2)
N3	0.0199 (3)	0.0182 (3)	0.0232 (3)	−0.0010 (2)	0.0023 (2)	−0.0019 (2)
C13	0.0129 (2)	0.0132 (2)	0.0154 (2)	−0.00052 (19)	0.00216 (18)	0.00055 (19)
C7	0.0125 (2)	0.0143 (3)	0.0164 (2)	0.00031 (19)	0.00184 (19)	−0.0005 (2)
C25	0.0140 (3)	0.0138 (3)	0.0178 (3)	0.0000 (2)	0.0026 (2)	−0.0008 (2)
C19	0.0134 (3)	0.0134 (2)	0.0172 (3)	−0.0002 (2)	0.00076 (19)	0.0011 (2)
N2	0.0195 (3)	0.0255 (3)	0.0282 (3)	0.0002 (3)	0.0012 (2)	0.0020 (3)
C14	0.0166 (3)	0.0148 (3)	0.0217 (3)	0.0006 (2)	0.0024 (2)	−0.0017 (2)
C1	0.0144 (3)	0.0201 (3)	0.0198 (3)	0.0008 (2)	0.0009 (2)	0.0002 (2)
C30	0.0148 (3)	0.0174 (3)	0.0183 (3)	0.0014 (2)	0.0033 (2)	0.0007 (2)
C24	0.0160 (3)	0.0140 (3)	0.0248 (3)	−0.0005 (2)	0.0006 (2)	−0.0016 (2)
C18	0.0153 (3)	0.0212 (3)	0.0165 (3)	0.0001 (2)	0.0015 (2)	0.0013 (2)
C20	0.0155 (3)	0.0239 (3)	0.0170 (3)	−0.0030 (2)	0.0020 (2)	0.0015 (2)
C3	0.0185 (3)	0.0193 (3)	0.0236 (3)	0.0012 (2)	0.0041 (2)	0.0030 (2)
C12	0.0151 (3)	0.0161 (3)	0.0220 (3)	−0.0018 (2)	0.0010 (2)	0.0000 (2)
C8	0.0150 (3)	0.0188 (3)	0.0200 (3)	0.0010 (2)	0.0003 (2)	0.0025 (2)
C5	0.0169 (3)	0.0162 (3)	0.0223 (3)	−0.0007 (2)	0.0019 (2)	−0.0001 (2)
C15	0.0178 (3)	0.0144 (3)	0.0365 (4)	0.0019 (2)	0.0035 (3)	−0.0005 (3)
C21	0.0168 (3)	0.0344 (4)	0.0213 (3)	−0.0047 (3)	0.0026 (2)	0.0067 (3)
C23	0.0162 (3)	0.0153 (3)	0.0374 (4)	−0.0026 (2)	−0.0012 (3)	0.0009 (3)
C11	0.0155 (3)	0.0222 (3)	0.0287 (4)	−0.0046 (3)	0.0003 (3)	−0.0036 (3)
C9	0.0157 (3)	0.0299 (4)	0.0205 (3)	0.0035 (3)	−0.0010 (2)	0.0025 (3)
C29	0.0184 (3)	0.0255 (4)	0.0201 (3)	0.0023 (3)	0.0058 (2)	0.0001 (3)
C17	0.0169 (3)	0.0290 (4)	0.0229 (3)	0.0003 (3)	−0.0007 (2)	0.0087 (3)
C2	0.0181 (3)	0.0290 (4)	0.0269 (4)	0.0044 (3)	0.0033 (3)	0.0104 (3)
B1	0.0131 (3)	0.0123 (3)	0.0154 (3)	−0.0002 (2)	0.0019 (2)	0.0004 (2)
C26	0.0235 (3)	0.0145 (3)	0.0305 (4)	0.0016 (3)	0.0104 (3)	0.0005 (3)
C10	0.0138 (3)	0.0332 (4)	0.0242 (3)	−0.0009 (3)	−0.0022 (2)	−0.0052 (3)
C16	0.0177 (3)	0.0204 (3)	0.0379 (4)	0.0027 (3)	0.0000 (3)	0.0100 (3)
C22	0.0155 (3)	0.0254 (4)	0.0356 (4)	−0.0052 (3)	0.0012 (3)	0.0103 (3)
C6	0.0204 (3)	0.0201 (3)	0.0229 (3)	−0.0010 (3)	0.0020 (2)	−0.0046 (3)
C28	0.0233 (4)	0.0251 (4)	0.0303 (4)	0.0015 (3)	0.0106 (3)	−0.0078 (3)
N4	0.0354 (5)	0.0369 (5)	0.0314 (4)	−0.0089 (4)	0.0047 (3)	−0.0058 (3)
C4	0.0184 (3)	0.0312 (4)	0.0345 (4)	−0.0038 (3)	−0.0001 (3)	0.0013 (3)
C31	0.0248 (4)	0.0291 (4)	0.0192 (3)	0.0000 (3)	0.0019 (3)	−0.0043 (3)
C27	0.0286 (4)	0.0161 (3)	0.0421 (5)	0.0018 (3)	0.0153 (4)	−0.0051 (3)
C32	0.0308 (4)	0.0244 (4)	0.0240 (4)	−0.0002 (3)	0.0014 (3)	0.0008 (3)

Geometric parameters (Å, º)

Cr1—N1^i	2.0915 (7)	C5—C6	1.4496 (11)
Cr1—N1	2.0916 (7)	C15—C16	1.3920 (14)
Cr1—N3^i	2.0673 (7)	C15—H15	0.949 (14)
Cr1—N3	2.0673 (7)	C21—C22	1.3944 (14)
Cr1—N2	2.4267 (8)	C21—H21	0.949 (13)
Cr1—N2^i	2.4267 (8)	C23—C22	1.3906 (14)
N1—C1	1.1438 (11)	C23—H23	0.997 (15)
N3—C5	1.1441 (11)	C11—C10	1.3949 (13)
C13—C14	1.4054 (10)	C11—H11	0.965 (14)
C13—C18	1.4059 (10)	C9—H9	0.9500
C13—B1	1.6400 (10)	C9—C10	1.3900 (13)
C7—C12	1.4095 (10)	C29—C28	1.3919 (13)
C7—C8	1.4064 (10)	C29—H29	1.001 (14)
C7—B1	1.6414 (11)	C17—C16	1.3918 (14)
C25—C30	1.4054 (10)	C17—H17	0.982 (15)
C25—B1	1.6453 (10)	C2—H2A	0.9800
C25—C26	1.4049 (11)	C2—H2B	0.9800
C19—C24	1.4083 (10)	C2—H2C	0.9800
C19—C20	1.4069 (10)	C26—H26	0.9500
C19—B1	1.6448 (10)	C26—C27	1.3975 (11)
N2—C3	1.1433 (12)	C10—H10	0.9500
C14—C15	1.3953 (11)	C16—H16	0.9500
C14—H14	1.025 (13)	C22—H22	0.9500
C1—C2	1.4485 (11)	C6—H6A	0.9800
C30—C29	1.3963 (10)	C6—H6B	0.9800
C30—H30	0.968 (13)	C6—H6C	0.9800
C24—C23	1.3985 (11)	C28—H28	0.9500
C24—H24	0.999 (13)	C28—C27	1.3909 (13)
C18—C17	1.3946 (12)	N4—C31	1.1459 (14)
C18—H18	0.970 (13)	C4—H4A	0.9800
C20—C21	1.3965 (11)	C4—H4B	0.9800
C20—H20	0.986 (13)	C4—H4C	0.9800
C3—C4	1.4544 (13)	C31—C32	1.4565 (13)
C12—C11	1.3959 (11)	C27—H27	0.9500
C12—H12	0.963 (13)	C32—H32A	0.9800
C8—C9	1.3965 (11)	C32—H32B	0.9800
C8—H8	1.002 (12)	C32—H32C	0.9800
N1^i—Cr1—N1	88.91 (4)	C22—C23—H23	118.8 (9)
N1^i—Cr1—N2^i	85.62 (3)	C12—C11—H11	118.9 (9)
N1^i—Cr1—N2	94.16 (3)	C10—C11—C12	120.43 (8)
N1—Cr1—N2^i	94.16 (3)	C10—C11—H11	120.7 (9)
N1—Cr1—N2	85.63 (3)	C8—C9—H9	119.9
N3—Cr1—N1^i	176.88 (3)	C10—C9—C8	120.27 (8)
N3^i—Cr1—N1	176.88 (3)	C10—C9—H9	119.9
N3—Cr1—N1	89.54 (3)	C30—C29—H29	117.5 (8)
N3^i—Cr1—N1^i	89.54 (3)	C28—C29—C30	120.45 (7)
N3^i—Cr1—N3	92.14 (4)	C28—C29—H29	122.0 (8)
N3^i—Cr1—N2^i	88.42 (3)	C18—C17—H17	119.2 (9)
N3—Cr1—N2^i	91.79 (3)	C16—C17—C18	120.11 (8)
N3—Cr1—N2	88.42 (3)	C16—C17—H17	120.7 (9)
N3^i—Cr1—N2	91.79 (3)	C1—C2—H2A	109.5
N2^i—Cr1—N2	179.70 (4)	C1—C2—H2B	109.5
C1—N1—Cr1	171.86 (7)	C1—C2—H2C	109.5
C5—N3—Cr1	173.92 (7)	H2A—C2—H2B	109.5
C14—C13—C18	115.58 (7)	H2A—C2—H2C	109.5
C14—C13—B1	122.14 (6)	H2B—C2—H2C	109.5
C18—C13—B1	121.91 (6)	C13—B1—C7	112.43 (6)
C12—C7—B1	122.57 (6)	C13—B1—C25	111.96 (6)
C8—C7—C12	115.43 (7)	C13—B1—C19	103.66 (5)
C8—C7—B1	121.63 (6)	C7—B1—C25	104.29 (5)
C30—C25—B1	121.34 (6)	C7—B1—C19	112.20 (6)
C26—C25—C30	115.46 (6)	C19—B1—C25	112.56 (6)
C26—C25—B1	122.98 (6)	C25—C26—H26	118.7
C24—C19—B1	122.35 (6)	C27—C26—C25	122.67 (8)
C20—C19—C24	115.48 (7)	C27—C26—H26	118.7
C20—C19—B1	121.77 (6)	C11—C10—H10	120.7
C3—N2—Cr1	152.62 (7)	C9—C10—C11	118.68 (8)
C13—C14—H14	119.3 (7)	C9—C10—H10	120.7
C15—C14—C13	122.48 (8)	C15—C16—C17	118.85 (8)
C15—C14—H14	118.2 (7)	C15—C16—H16	120.6
N1—C1—C2	179.59 (10)	C17—C16—H16	120.6
C25—C30—H30	118.8 (7)	C21—C22—H22	120.5
C29—C30—C25	122.49 (7)	C23—C22—C21	118.96 (7)
C29—C30—H30	118.7 (7)	C23—C22—H22	120.5
C19—C24—H24	120.0 (8)	C5—C6—H6A	109.5
C23—C24—C19	122.62 (8)	C5—C6—H6B	109.5
C23—C24—H24	117.4 (8)	C5—C6—H6C	109.5
C13—C18—H18	118.0 (8)	H6A—C6—H6B	109.5
C17—C18—C13	122.67 (7)	H6A—C6—H6C	109.5
C17—C18—H18	119.3 (8)	H6B—C6—H6C	109.5
C19—C20—H20	117.8 (8)	C29—C28—H28	120.7
C21—C20—C19	122.65 (8)	C27—C28—C29	118.61 (7)
C21—C20—H20	119.6 (8)	C27—C28—H28	120.7
N2—C3—C4	179.13 (10)	C3—C4—H4A	109.5
C7—C12—H12	117.5 (8)	C3—C4—H4B	109.5
C11—C12—C7	122.42 (7)	C3—C4—H4C	109.5
C11—C12—H12	120.1 (8)	H4A—C4—H4B	109.5
C7—C8—H8	118.4 (7)	H4A—C4—H4C	109.5
C9—C8—C7	122.75 (7)	H4B—C4—H4C	109.5
C9—C8—H8	118.8 (7)	N4—C31—C32	178.91 (11)
N3—C5—C6	179.05 (9)	C26—C27—H27	119.9
C14—C15—H15	120.1 (9)	C28—C27—C26	120.24 (8)
C16—C15—C14	120.28 (8)	C28—C27—H27	119.9
C16—C15—H15	119.6 (9)	C31—C32—H32A	109.5
C20—C21—H21	119.3 (8)	C31—C32—H32B	109.5
C22—C21—C20	120.14 (8)	C31—C32—H32C	109.5
C22—C21—H21	120.6 (8)	H32A—C32—H32B	109.5
C24—C23—H23	121.0 (9)	H32A—C32—H32C	109.5
C22—C23—C24	120.13 (8)	H32B—C32—H32C	109.5
C13—C14—C15—C16	0.20 (12)	C20—C19—C24—C23	1.65 (11)
C13—C18—C17—C16	0.60 (12)	C20—C19—B1—C13	84.34 (8)
C7—C12—C11—C10	−0.29 (12)	C20—C19—B1—C7	−37.21 (9)
C7—C8—C9—C10	−0.12 (12)	C20—C19—B1—C25	−154.48 (7)
C25—C30—C29—C28	0.54 (13)	C20—C21—C22—C23	1.42 (14)
C25—C26—C27—C28	−0.71 (16)	C12—C7—C8—C9	−0.97 (11)
C19—C24—C23—C22	−0.31 (13)	C12—C7—B1—C13	34.25 (9)
C19—C20—C21—C22	0.00 (14)	C12—C7—B1—C25	−87.25 (8)
C14—C13—C18—C17	−1.65 (11)	C12—C7—B1—C19	150.63 (6)
C14—C13—B1—C7	36.67 (9)	C12—C11—C10—C9	−0.86 (13)
C14—C13—B1—C25	153.70 (6)	C8—C7—C12—C11	1.17 (11)
C14—C13—B1—C19	−84.72 (8)	C8—C7—B1—C13	−153.03 (6)
C14—C15—C16—C17	−1.32 (13)	C8—C7—B1—C25	85.46 (7)
C30—C25—B1—C13	−36.61 (9)	C8—C7—B1—C19	−36.65 (9)
C30—C25—B1—C7	85.20 (8)	C8—C9—C10—C11	1.06 (12)
C30—C25—B1—C19	−152.92 (7)	C29—C28—C27—C26	−1.57 (16)
C30—C25—C26—C27	2.75 (13)	B1—C13—C14—C15	174.35 (7)
C30—C29—C28—C27	1.65 (14)	B1—C13—C18—C17	−174.77 (7)
C24—C19—C20—C21	−1.49 (12)	B1—C7—C12—C11	174.30 (7)
C24—C19—B1—C13	−88.08 (8)	B1—C7—C8—C9	−174.17 (7)
C24—C19—B1—C7	150.37 (7)	B1—C25—C30—C29	−177.52 (7)
C24—C19—B1—C25	33.10 (9)	B1—C25—C26—C27	177.51 (9)
C24—C23—C22—C21	−1.27 (13)	B1—C19—C24—C23	174.51 (7)
C18—C13—C14—C15	1.25 (11)	B1—C19—C20—C21	−174.40 (8)
C18—C13—B1—C7	−150.66 (6)	C26—C25—C30—C29	−2.66 (12)
C18—C13—B1—C25	−33.63 (9)	C26—C25—B1—C13	148.92 (7)
C18—C13—B1—C19	87.95 (7)	C26—C25—B1—C7	−89.26 (8)
C18—C17—C16—C15	0.94 (13)	C26—C25—B1—C19	32.61 (10)

Symmetry code: (i) −x+1, y, −z+1/2.

(2) Hexakis(acetonitrile-κN)chromium(II) bis(tetraphenylborate) acetonitrile disolvate

Crystal data

[Cr(C2H3N)6](C24H20B)2·2C2H3N	F(000) = 2152
Mr = 1018.92	Dx = 1.183 Mg m^−3
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71073 Å
a = 18.8632 (3) Å	Cell parameters from 9787 reflections
b = 14.6756 (2) Å	θ = 2.6–47.0°
c = 20.7596 (3) Å	µ = 0.25 mm^−1
β = 95.230 (1)°	T = 110 K
V = 5722.93 (15) Å^3	Prism, green
Z = 4	0.37 × 0.34 × 0.18 mm

Data collection

Bruker APEXII CCD area-detector diffractometer	26260 independent reflections
Radiation source: fine-focus sealed tube	12685 reflections with I ≥ 3σ(I)
Graphite monochromator	Rint = 0.05
φ and ω scans	θmax = 47.6°, θmin = 1.8°
Absorption correction: multi-scan (SADABS; Bruker, 2014)	h = −39→38
Tmin = 0.594, Tmax = 0.749	k = 0→30
129273 measured reflections	l = 0→42

Refinement

Refinement on F	0 restraints
Least-squares matrix: full	All H-atom parameters refined
R[F^2 > 2σ(F^2)] = 0.035	, w1 = [Fo*sqrt(w2) + sqrt(Fo^2w2^2 + sqrt(w2^2))]^2 where w2 = q/[s^2(Fo^2) + (0.05 P)^2 + 0.00 P + 0.00 + 0.00 sin(th)] where P = (0.3333 Fo^2 + 0.667 Fc^2) q = 1.0
wR(F^2) = 0.043	(Δ/σ)max = 0.012
S = 1.15	Δρmax = 0.33 e Å^−3
12582 reflections	Δρmin = −0.33 e Å^−3
629 parameters

Special details

Experimental. Absorption correction: SADABS-2012/1 (Bruker, 2014) was used for absorption correction. wR2(int) was 0.0831 before and 0.0669 after correction. The Ratio of minimum to maximum transmission is 0.7925. The λ/2 correction factor is 0.0015.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Cr1	0.5	0.733568 (19)	0.25	0.016
N1	0.50950 (6)	0.63177 (8)	0.32079 (5)	0.019
N2	0.62897 (7)	0.73303 (9)	0.25852 (6)	0.024
N3	0.50456 (6)	0.83125 (8)	0.32189 (6)	0.02
N4	0.83713 (9)	0.54132 (14)	0.64749 (7)	0.033
C1	0.52292 (5)	0.57447 (7)	0.35753 (5)	0.018
C2	0.53904 (5)	0.50184 (8)	0.40340 (5)	0.024
C3	0.68377 (6)	0.75398 (7)	0.28291 (5)	0.02
C4	0.75345 (6)	0.77953 (8)	0.31288 (6)	0.027
C5	0.50667 (5)	0.87936 (7)	0.36574 (5)	0.018
C6	0.50899 (5)	0.93858 (7)	0.42149 (5)	0.02
C7	0.71086 (3)	0.43574 (5)	0.35129 (3)	0.014
C8	0.68534 (4)	0.49372 (5)	0.30031 (3)	0.017
C9	0.63005 (4)	0.46889 (6)	0.25418 (4)	0.022
C10	0.59776 (4)	0.38373 (7)	0.25730 (4)	0.023
C11	0.62104 (4)	0.32495 (6)	0.30786 (4)	0.022
C12	0.67622 (4)	0.35094 (5)	0.35377 (3)	0.017
C13	0.81873 (3)	0.38602 (5)	0.44096 (3)	0.013
C14	0.83941 (4)	0.31190 (5)	0.40409 (3)	0.017
C15	0.88529 (4)	0.24393 (5)	0.43008 (4)	0.022
C16	0.91253 (4)	0.24743 (6)	0.49485 (5)	0.025
C17	0.89388 (4)	0.32114 (6)	0.53253 (4)	0.022
C18	0.84825 (4)	0.38873 (5)	0.50561 (3)	0.017
C19	0.82990 (3)	0.53875 (4)	0.38071 (3)	0.014
C20	0.85515 (4)	0.52500 (5)	0.31971 (3)	0.018
C21	0.90974 (4)	0.57739 (6)	0.29744 (4)	0.023
C22	0.94176 (4)	0.64675 (6)	0.33613 (5)	0.025
C23	0.91911 (4)	0.66089 (5)	0.39756 (4)	0.022
C24	0.86452 (4)	0.60756 (5)	0.41902 (4)	0.018
C25	0.72387 (3)	0.52063 (5)	0.46149 (3)	0.014
C26	0.70630 (4)	0.61381 (5)	0.45835 (4)	0.022
C27	0.66426 (5)	0.65535 (6)	0.50204 (5)	0.028
C28	0.63712 (5)	0.60416 (6)	0.55088 (4)	0.025
C29	0.65152 (4)	0.51098 (6)	0.55386 (3)	0.02
C30	0.69369 (4)	0.47048 (5)	0.50985 (3)	0.016
C31	0.80665 (5)	0.47441 (10)	0.65537 (4)	0.024
C32	0.76930 (5)	0.38967 (8)	0.66486 (4)	0.026
B1	0.77072 (4)	0.47034 (5)	0.40857 (3)	0.013
H2A	0.498 (3)	0.487 (2)	0.4170 (15)	0.091 (9)
H2B	0.570 (2)	0.524 (2)	0.435 (2)	0.096 (10)
H2C	0.5564 (17)	0.456 (3)	0.3819 (16)	0.083 (8)
H4A	0.7810 (15)	0.723 (2)	0.3177 (11)	0.064 (6)
H4B	0.7465 (12)	0.8074 (18)	0.3561 (19)	0.076 (7)
H4C	0.7759 (15)	0.820 (2)	0.2813 (15)	0.078 (7)
H6A	0.483 (2)	0.913 (2)	0.450 (2)	0.092 (9)
H6B	0.4927 (18)	0.991 (4)	0.4084 (15)	0.097 (10)
H6C	0.555 (3)	0.9443 (17)	0.4368 (15)	0.086 (9)
H8	0.7080 (8)	0.5575 (14)	0.2967 (6)	0.040 (4)
H9	0.6140 (9)	0.5136 (13)	0.2182 (10)	0.056 (4)
H10	0.5570 (13)	0.3652 (11)	0.2233 (11)	0.062 (5)
H11	0.5975 (9)	0.2626 (15)	0.3105 (7)	0.051 (4)
H12	0.6913 (8)	0.3072 (12)	0.3899 (9)	0.040 (4)
H14	0.8216 (8)	0.3084 (9)	0.3564 (10)	0.041 (4)
H15	0.9001 (9)	0.1912 (15)	0.4016 (9)	0.061 (5)
H16	0.9466 (12)	0.1972 (16)	0.5137 (9)	0.058 (5)
H17	0.9145 (9)	0.3263 (10)	0.5794 (12)	0.056 (4)
H18	0.8369 (7)	0.4431 (13)	0.5331 (8)	0.040 (4)
H20	0.8341 (8)	0.4735 (13)	0.2907 (8)	0.045 (4)
H21	0.9261 (8)	0.5640 (10)	0.2530 (11)	0.052 (4)
H22	0.9836 (13)	0.6853 (14)	0.3204 (8)	0.061 (5)
H23	0.9438 (10)	0.7103 (15)	0.4255 (9)	0.059 (5)
H24	0.8486 (7)	0.6207 (9)	0.4644 (9)	0.035 (3)
H26	0.7242 (8)	0.6533 (12)	0.4235 (9)	0.045 (4)
H27	0.6538 (9)	0.7224 (17)	0.4988 (8)	0.059 (5)
H28	0.6082 (11)	0.6346 (12)	0.5827 (11)	0.056 (5)
H29	0.6316 (8)	0.4708 (12)	0.5895 (9)	0.047 (4)
H30	0.7025 (7)	0.4020 (14)	0.5128 (6)	0.038 (3)
H32A	0.7626 (8)	0.3589 (16)	0.6268 (17)	0.082 (6)
H32B	0.7262 (17)	0.4041 (12)	0.6810 (9)	0.074 (5)
H32C	0.7961 (14)	0.3542 (18)	0.6948 (14)	0.086 (6)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cr1	0.01741 (12)	0.01404 (11)	0.01707 (11)	0	0.00101 (8)	0
N1	0.0204 (4)	0.0180 (4)	0.0188 (4)	0.0014 (3)	0.0004 (3)	0.0024 (3)
N2	0.0163 (4)	0.0264 (5)	0.0281 (5)	−0.0014 (4)	−0.0007 (4)	0.0013 (4)
N3	0.0210 (4)	0.0173 (4)	0.0207 (4)	−0.0014 (3)	0.0027 (3)	−0.0047 (3)
N4	0.0347 (7)	0.0332 (7)	0.0313 (6)	−0.0115 (6)	0.0056 (5)	−0.0056 (5)
C1	0.0159 (3)	0.0188 (4)	0.0180 (3)	0.0018 (3)	0.0002 (3)	0.0027 (3)
C2	0.0172 (4)	0.0288 (5)	0.0256 (4)	0.0041 (3)	0.0032 (3)	0.0099 (4)
C3	0.0156 (4)	0.0207 (4)	0.0231 (4)	0.0000 (3)	0.0025 (3)	0.0023 (3)
C4	0.0188 (4)	0.0298 (5)	0.0329 (5)	−0.0030 (4)	−0.0001 (4)	0.0013 (4)
C5	0.0183 (4)	0.0159 (4)	0.0194 (4)	−0.0004 (3)	0.0019 (3)	−0.0032 (3)
C6	0.0196 (4)	0.0196 (4)	0.0223 (4)	−0.0008 (3)	0.0022 (3)	−0.0045 (3)
C7	0.0119 (2)	0.0136 (3)	0.0152 (2)	−0.00058 (19)	0.00049 (19)	0.00021 (19)
C8	0.0147 (3)	0.0185 (3)	0.0184 (3)	0.0006 (2)	−0.0006 (2)	0.0032 (2)
C9	0.0151 (3)	0.0295 (4)	0.0194 (3)	0.0021 (2)	−0.0020 (2)	0.0026 (3)
C10	0.0138 (3)	0.0316 (4)	0.0231 (3)	−0.0013 (3)	−0.0026 (2)	−0.0043 (3)
C11	0.0152 (3)	0.0224 (3)	0.0269 (3)	−0.0049 (2)	−0.0013 (2)	−0.0027 (3)
C12	0.0148 (3)	0.0159 (3)	0.0209 (3)	−0.0029 (2)	0.0000 (2)	0.0000 (2)
C13	0.0130 (2)	0.0127 (2)	0.0138 (2)	0.00057 (19)	0.00163 (18)	0.00023 (19)
C14	0.0165 (3)	0.0144 (3)	0.0200 (3)	0.0017 (2)	0.0018 (2)	−0.0022 (2)
C15	0.0177 (3)	0.0142 (3)	0.0346 (4)	0.0028 (2)	0.0026 (3)	−0.0006 (3)
C16	0.0184 (3)	0.0202 (3)	0.0350 (4)	0.0033 (3)	−0.0006 (3)	0.0088 (3)
C17	0.0166 (3)	0.0286 (4)	0.0215 (3)	0.0017 (3)	−0.0011 (2)	0.0082 (3)
C18	0.0151 (3)	0.0206 (3)	0.0151 (2)	0.0008 (2)	0.00065 (19)	0.0011 (2)
C19	0.0131 (2)	0.0133 (2)	0.0157 (2)	−0.00122 (19)	0.00122 (18)	0.00033 (19)
C20	0.0150 (3)	0.0242 (3)	0.0154 (2)	−0.0040 (2)	0.00233 (19)	0.0013 (2)
C21	0.0164 (3)	0.0340 (4)	0.0200 (3)	−0.0063 (3)	0.0026 (2)	0.0062 (3)
C22	0.0155 (3)	0.0252 (4)	0.0331 (4)	−0.0060 (3)	0.0014 (3)	0.0091 (3)
C23	0.0157 (3)	0.0155 (3)	0.0352 (4)	−0.0036 (2)	−0.0003 (3)	0.0004 (3)
C24	0.0152 (3)	0.0141 (3)	0.0233 (3)	−0.0017 (2)	0.0007 (2)	−0.0023 (2)
C25	0.0143 (2)	0.0127 (3)	0.0165 (2)	0.00037 (19)	0.00345 (19)	−0.00026 (19)
C26	0.0237 (3)	0.0134 (3)	0.0302 (3)	0.0023 (2)	0.0115 (3)	0.0003 (2)
C27	0.0290 (4)	0.0155 (3)	0.0409 (4)	0.0020 (3)	0.0169 (3)	−0.0051 (3)
C28	0.0239 (3)	0.0233 (4)	0.0293 (4)	0.0018 (3)	0.0115 (3)	−0.0068 (3)
C29	0.0186 (3)	0.0239 (3)	0.0193 (3)	0.0028 (2)	0.0065 (2)	0.0001 (2)
C30	0.0147 (3)	0.0172 (3)	0.0171 (2)	0.0016 (2)	0.00390 (19)	0.0010 (2)
C31	0.0243 (3)	0.0272 (4)	0.0192 (3)	−0.0020 (4)	0.0021 (2)	−0.0036 (3)
C32	0.0302 (4)	0.0236 (4)	0.0226 (3)	−0.0006 (3)	0.0013 (3)	0.0008 (3)
B1	0.0121 (3)	0.0120 (3)	0.0140 (3)	−0.0005 (2)	0.0017 (2)	0.0004 (2)

Geometric parameters (Å, º)

Cr1—N1	2.0918 (11)	C1—C2	1.4432 (14)
Cr1—N2	2.4231 (13)	C3—C4	1.4513 (16)
Cr1—N3	2.0655 (12)	C5—C6	1.4448 (14)
N1—C1	1.1480 (14)	C4—H4A	0.98 (4)
N2—C3	1.1507 (15)	C4—H4B	1.01 (4)
N3—C5	1.1499 (13)	C4—H4C	1.01 (4)
N1—Cr1—N2	85.71 (4)	Cr1—N3—C5	173.90 (11)
N1—Cr1—N3	89.59 (5)	C3—C4—H4B	107.5 (13)
N1—Cr1—N2^i	94.02 (4)	C3—C4—H4C	106.9 (13)
N2^i—Cr1—N3^i	88.52 (4)	H4A—C4—H4B	111.5 (17)
Cr1—N1—C1	171.71 (10)	H4A—C4—H4C	108.5 (17)
Cr1—N2—C3	152.49 (11)

Symmetry code: (i) −x+1, y, −z+1/2.

(3) Hexakis(acetonitrile-κN)chromium(II) bis(tetraphenylborate) acetonitrile disolvate

Crystal data

[Cr(C2H3N)6](C24H20B)2·2C2H3N	F(000) = 2152
Mr = 1018.92	Dx = 1.183 Mg m^−3
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71073 Å
a = 18.8632 (3) Å	Cell parameters from 9787 reflections
b = 14.6756 (2) Å	µ = 0.25 mm^−1
c = 20.7596 (3) Å	T = 110 K
β = 95.230 (1)°	Prism, green
V = 5722.93 (15) Å^3	0.37 × 0.34 × 0.18 mm
Z = 4

Data collection

Bruker APEXII CCD area-detector diffractometer	26260 independent reflections
Radiation source: fine-focus sealed tube	12685 reflections with I ≥ 3σ(I)
Graphite monochromator	Rint = 0.05
φ and ω scans	θmax = 47.6°, θmin = 1.8°
Absorption correction: multi-scan (SADABS; Bruker, 2014)	h = −39→38
Tmin = 0.594, Tmax = 0.749	k = 0→30
129273 measured reflections	l = 0→42

Refinement

Refinement on F	0 restraints
Least-squares matrix: full	Only H-atom displacement parameters refined
R[F^2 > 2σ(F^2)] = 0.036	, w1 = [Fo*sqrt(w2) + sqrt(Fo^2w2^2 + sqrt(w2^2))]^2 where w2 = q/[s^2(Fo^2) + (0.05 P)^2 + 0.00 P + 0.00 + 0.00 sin(th)] where P = (0.3333 Fo^2 + 0.6667 Fc^2) q = 1.0
wR(F^2) = 0.044	(Δ/σ)max = 0.001
S = 1.20	Δρmax = 0.44 e Å^−3
12582 reflections	Δρmin = −0.48 e Å^−3
495 parameters

Special details

Experimental. Absorption correction: SADABS-2012/1 (Bruker, 2014) was used for absorption correction. wR2(int) was 0.0831 before and 0.0669 after correction. The Ratio of minimum to maximum transmission is 0.7925. The λ/2 correction factor is 0.0015.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Cr1	0.5	0.733561 (11)	0.25	0.016
N1	0.50956 (4)	0.63191 (4)	0.32080 (3)	0.02
N2	0.62912 (4)	0.73310 (5)	0.25868 (4)	0.025
N3	0.50453 (4)	0.83122 (4)	0.32197 (3)	0.02
N4	0.83713 (5)	0.54131 (7)	0.64750 (4)	0.033
C1	0.52284 (4)	0.57455 (5)	0.35745 (3)	0.018
C2	0.53904 (5)	0.50195 (8)	0.40335 (5)	0.024
C3	0.68386 (4)	0.75402 (5)	0.28296 (4)	0.02
C4	0.75340 (6)	0.77950 (8)	0.31285 (6)	0.028
C5	0.50665 (4)	0.87930 (5)	0.36568 (3)	0.018
C6	0.50897 (5)	0.93851 (7)	0.42144 (4)	0.021
C7	0.71085 (4)	0.43574 (5)	0.35128 (3)	0.014
C8	0.68531 (4)	0.49359 (5)	0.30033 (3)	0.018
C9	0.63009 (4)	0.46879 (6)	0.25426 (4)	0.022
C10	0.59784 (4)	0.38375 (7)	0.25737 (4)	0.024
C11	0.62107 (4)	0.32508 (6)	0.30784 (4)	0.022
C12	0.67620 (4)	0.35102 (5)	0.35370 (4)	0.018
C13	0.81873 (3)	0.38602 (5)	0.44096 (3)	0.014
C14	0.83944 (4)	0.31191 (5)	0.40417 (4)	0.017
C15	0.88526 (4)	0.24404 (5)	0.43012 (5)	0.023
C16	0.91246 (4)	0.24753 (6)	0.49483 (5)	0.025
C17	0.89384 (4)	0.32114 (6)	0.53243 (4)	0.023
C18	0.84825 (4)	0.38865 (5)	0.50555 (3)	0.017
C19	0.82990 (4)	0.53876 (5)	0.38070 (3)	0.015
C20	0.85518 (4)	0.52508 (5)	0.31976 (3)	0.019
C21	0.90970 (4)	0.57742 (6)	0.29755 (4)	0.024
C22	0.94169 (4)	0.64667 (6)	0.33618 (5)	0.025
C23	0.91907 (4)	0.66081 (5)	0.39750 (4)	0.023
C24	0.86453 (4)	0.60752 (5)	0.41895 (4)	0.018
C25	0.72387 (4)	0.52063 (5)	0.46151 (3)	0.015
C26	0.70626 (4)	0.61374 (5)	0.45842 (4)	0.023
C27	0.66427 (5)	0.65522 (6)	0.50203 (5)	0.028
C28	0.63717 (5)	0.60410 (6)	0.55082 (4)	0.026
C29	0.65156 (4)	0.51107 (6)	0.55379 (4)	0.021
C30	0.69369 (4)	0.47060 (5)	0.50983 (3)	0.017
C31	0.80665 (5)	0.47447 (8)	0.65536 (4)	0.024
C32	0.76939 (5)	0.38988 (8)	0.66485 (4)	0.026
B1	0.77072 (4)	0.47032 (5)	0.40857 (4)	0.013
H2A	0.490322	0.478607	0.422591	0.064 (9)
H2B	0.57583	0.526667	0.44305	0.074 (10)
H2C	0.563541	0.445224	0.379751	0.062 (9)
H4A	0.786294	0.718765	0.320845	0.067 (8)
H4B	0.747747	0.812894	0.359001	0.078 (10)
H4C	0.778691	0.826234	0.281158	0.073 (9)
H6A	0.477802	0.908644	0.457794	0.072 (9)
H6B	0.486795	1.004853	0.407162	0.084 (11)
H6C	0.563896	0.946878	0.441849	0.076 (10)
H8	0.709473	0.560129	0.29675	0.024 (3)
H9	0.612246	0.516029	0.216094	0.038 (4)
H10	0.555677	0.36348	0.221306	0.045 (5)
H11	0.596222	0.258975	0.311455	0.033 (4)
H12	0.692885	0.30422	0.392488	0.027 (4)
H14	0.819112	0.30733	0.35377	0.029 (4)
H15	0.900025	0.188206	0.399959	0.044 (5)
H16	0.947296	0.194456	0.515605	0.040 (4)
H17	0.91486	0.325532	0.582647	0.039 (4)
H18	0.835211	0.445256	0.535788	0.027 (4)
H20	0.831271	0.471908	0.288789	0.033 (4)
H21	0.927276	0.564723	0.25014	0.035 (4)
H22	0.983241	0.688596	0.318894	0.046 (5)
H23	0.943855	0.713433	0.428444	0.041 (5)
H24	0.848412	0.619657	0.466963	0.021 (3)
H26	0.726295	0.654963	0.420787	0.031 (4)
H27	0.652651	0.727389	0.498159	0.041 (5)
H28	0.605875	0.635975	0.585812	0.040 (5)
H29	0.630122	0.469865	0.590705	0.030 (4)
H30	0.703416	0.397963	0.513286	0.026 (4)
H32A	0.761316	0.35311	0.619153	0.064 (9)
H32B	0.717914	0.404371	0.682562	0.040 (7)
H32C	0.800769	0.347898	0.700159	0.056 (8)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cr1	0.01708 (7)	0.01467 (7)	0.01684 (6)	0	0.00072 (5)	0
N1	0.0215 (3)	0.0185 (3)	0.0196 (2)	0.0014 (2)	0.00049 (19)	0.0023 (2)
N2	0.0175 (3)	0.0272 (3)	0.0283 (3)	−0.0009 (2)	−0.0005 (2)	0.0016 (2)
N3	0.0214 (3)	0.0185 (3)	0.0213 (2)	−0.0011 (2)	0.0023 (2)	−0.0040 (2)
N4	0.0350 (4)	0.0338 (4)	0.0318 (4)	−0.0112 (3)	0.0056 (3)	−0.0058 (3)
C1	0.0158 (3)	0.0198 (3)	0.0187 (2)	0.0015 (2)	0.0005 (2)	0.0024 (2)
C2	0.0175 (4)	0.0293 (5)	0.0262 (4)	0.0039 (3)	0.0033 (3)	0.0096 (4)
C3	0.0163 (3)	0.0214 (3)	0.0235 (3)	0.0000 (2)	0.0024 (2)	0.0024 (2)
C4	0.0195 (4)	0.0301 (5)	0.0334 (5)	−0.0029 (4)	0.0001 (4)	0.0011 (4)
C5	0.0183 (3)	0.0165 (3)	0.0202 (3)	−0.0005 (2)	0.0020 (2)	−0.0025 (2)
C6	0.0199 (4)	0.0202 (4)	0.0229 (4)	−0.0007 (3)	0.0022 (3)	−0.0042 (3)
C7	0.0125 (2)	0.0141 (3)	0.0160 (2)	−0.00060 (19)	0.00067 (19)	0.00026 (19)
C8	0.0153 (3)	0.0188 (3)	0.0192 (3)	0.0004 (2)	−0.0005 (2)	0.0032 (2)
C9	0.0159 (3)	0.0299 (4)	0.0199 (3)	0.0023 (3)	−0.0021 (2)	0.0030 (3)
C10	0.0144 (3)	0.0323 (4)	0.0236 (3)	−0.0016 (3)	−0.0030 (2)	−0.0043 (3)
C11	0.0159 (3)	0.0225 (3)	0.0277 (3)	−0.0052 (2)	−0.0011 (2)	−0.0026 (3)
C12	0.0156 (3)	0.0163 (3)	0.0214 (3)	−0.0028 (2)	−0.0001 (2)	0.0003 (2)
C13	0.0136 (2)	0.0133 (2)	0.0144 (2)	0.0006 (2)	0.00176 (18)	0.00017 (19)
C14	0.0172 (3)	0.0150 (3)	0.0202 (3)	0.0018 (2)	0.0017 (2)	−0.0022 (2)
C15	0.0184 (3)	0.0144 (3)	0.0354 (4)	0.0029 (2)	0.0027 (3)	−0.0009 (3)
C16	0.0191 (3)	0.0204 (3)	0.0358 (4)	0.0037 (3)	−0.0007 (3)	0.0089 (3)
C17	0.0175 (3)	0.0292 (4)	0.0218 (3)	0.0017 (3)	−0.0012 (2)	0.0081 (3)
C18	0.0158 (3)	0.0209 (3)	0.0156 (2)	0.0010 (2)	0.00073 (19)	0.0008 (2)
C19	0.0137 (2)	0.0138 (2)	0.0163 (2)	−0.0012 (2)	0.00134 (19)	0.0003 (2)
C20	0.0156 (3)	0.0247 (3)	0.0160 (2)	−0.0042 (2)	0.0023 (2)	0.0010 (2)
C21	0.0173 (3)	0.0348 (4)	0.0203 (3)	−0.0063 (3)	0.0029 (2)	0.0061 (3)
C22	0.0161 (3)	0.0257 (4)	0.0339 (4)	−0.0064 (3)	0.0017 (3)	0.0092 (3)
C23	0.0163 (3)	0.0159 (3)	0.0358 (4)	−0.0039 (2)	−0.0003 (3)	0.0001 (3)
C24	0.0160 (3)	0.0147 (3)	0.0236 (3)	−0.0018 (2)	0.0009 (2)	−0.0024 (2)
C25	0.0149 (2)	0.0132 (3)	0.0171 (2)	0.00040 (19)	0.0036 (2)	−0.0002 (2)
C26	0.0246 (3)	0.0138 (3)	0.0308 (3)	0.0022 (2)	0.0119 (3)	0.0005 (2)
C27	0.0300 (4)	0.0156 (3)	0.0418 (4)	0.0021 (3)	0.0171 (3)	−0.0052 (3)
C28	0.0249 (4)	0.0237 (4)	0.0299 (4)	0.0020 (3)	0.0121 (3)	−0.0068 (3)
C29	0.0194 (3)	0.0244 (3)	0.0198 (3)	0.0028 (2)	0.0068 (2)	0.0004 (2)
C30	0.0155 (3)	0.0173 (3)	0.0179 (2)	0.0017 (2)	0.0041 (2)	0.0010 (2)
C31	0.0247 (3)	0.0277 (4)	0.0196 (3)	−0.0019 (3)	0.0022 (2)	−0.0036 (3)
C32	0.0308 (4)	0.0246 (4)	0.0230 (3)	−0.0002 (4)	0.0013 (3)	0.0007 (3)
B1	0.0128 (3)	0.0126 (3)	0.0147 (3)	−0.0005 (2)	0.0018 (2)	0.0004 (2)

Geometric parameters (Å, º)

Cr1—N1	2.0904 (6)	C5—C6	1.4437 (11)
Cr1—N2	2.4259 (8)	C2—H2A	1.0900
Cr1—N3	2.0665 (6)	C2—H2B	1.0900
N1—C1	1.1469 (10)	C2—H2C	1.0900
N2—C3	1.1485 (11)	C4—H4A	1.0900
N3—C5	1.1472 (10)	C4—H4B	1.0900
C1—C2	1.4422 (12)	C4—H4C	1.0900
C3—C4	1.4467 (14)
N1—Cr1—N2	85.65 (3)	Cr1—N2—C3	152.63 (7)
N1—Cr1—N3	89.51 (2)	Cr1—N3—C5	174.02 (6)
N2—Cr1—N3	88.46 (3)	H4A—C4—H4B	109.41
N1^i—Cr1—N2	94.12 (3)	H4A—C4—H4C	109.32
Cr1—N1—C1	171.81 (7)	H4B—C4—H4C	109.24

Symmetry code: (i) −x+1, y, −z+1/2.