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The title compound, C20H32B2N4, is monoclinic at ambient temperature but triclinic (pseudo-monoclinic) below 150 K. The structures of the two phases, determined at 200 and 120 K, respectively, are very similar, the mol­ecular symmetry being crystallographic C2 and approximate (local) C2, respectively. There is significant π conjugation within each N—B—N moiety, but none between them or between the N—B—N and arene moieties.

Supporting information

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270111039230/mx3055sup1.cif
Contains datablocks global, bI, aI

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S0108270111039230/mx3055aIsup2.hkl
Contains datablock aI

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S0108270111039230/mx3055bIsup3.hkl
Contains datablock bI

mol

MDL mol file https://doi.org/10.1107/S0108270111039230/mx3055aIsup4.mol
Supplementary material

mol

MDL mol file https://doi.org/10.1107/S0108270111039230/mx3055bIsup5.mol
Supplementary material

CCDC references: 851743; 851744

Comment top

Tetra(amido)diborane(4) derivatives are important as precursors in diborane(4) chemistry (Brotherton, 1964), especially since the Suzuki reaction became widely used in the synthesis of complex molecular species (Miyaura & Suzuki, 1995). The title compound, (I), was first reported by Patton et al. (2001). In the course of our studies of substitution reactions in diboranes (Baber et al., 2005), we reproduced the synthesis of (I) and structurally characterized it by X-ray diffraction, which revealed a phase transition.

Under ambient conditions, (I) is monoclinic. On slow cooling, this α form (fully studied at 200 K) persisted to 160 K, as was indicated by express lattice determinations at 292, 274, 250, 230, 200, 180 and 160 K. The phase transition was observed between 160 and 150 K, at which point the peaks of most reflections became split, but the separations between the maxima were not wide enough to index the components separately. If flash-cooled below 150 K, the crystals shattered. After several unsuccessful attempts, we obtained just one crystal of the low-temperature phase, β-(I), by annealing a crystal with three cycles of cooling–heating above the phase transition (230 to 160 K) before finally cooling it down to 120 K. On warming to 230 K, the crystal remained triclinic, but cracked on warming to room temperature. We tried the annealing procedure on other samples but without success.

The structure of β-(I), determined from the data set collected at 120 K, is triclinic, although the actual difference from α-(I) is small. To simplify the comparison, β-(I) is presented here in the (non-standard) pseudo-monoclinic lattice setting analogous to that of α-(I). Interestingly, this lattice of β-(I) can be transformed by the operation (1 0 1 / 1 0 1 / 0 1 0) to a C-centred pseudo-monoclinic lattice with a = 15.844, b = 13.702 and c = 9.645 Å, α = 89.91, β = 93.46 and γ = 89.66°, and V = 2090 Å3. However, we found no approximate structural or Laue symmetry (Rint = 0.51) associated with this cell.

The molecular structure of (I) (Fig. 1) is very similar to that of its mesityl analogue, 1,2-bis(2,4,6-trimethylanilide)-1,2-bis-(dimethylamido)diborane, (II) (Firinci et al., 2010). In the α-(I) form, the molecule possesses a crystallographic twofold axis passing through the midpoint of the B—B bond. In the β form, this twofold symmetry was noncrystallographic yet almost perfect. In fact, the structure of β-(I) can be solved and refined to R1 = 0.125 (Rint = 0.255) in the space group P2/n of the α phase, ignoring the deviation of α and γ angles from 90°.

All B and N atoms have planar–trigonal geometry. In each case, the planes of a B atom and its two adjacent N atoms coincide within experimental error, and the B—N distances indicate a degree of multiple bonding (Weber et al., 2001). On the other hand, strong twists around the B—B bond [67.6 (2)° in α-(I) and 65.9 (2)° in β-(I)] and around the N—C(Ar) bonds [69.2 (2)° in α-(I), and 67.1 (2) and 68.8 (2)° in β-(I)] preclude any π-conjugation. Thus, the B—B bond is essentially single; its length falls within the usual range of 1.69–1.75 Å for tetramido-diborane derivatives (Weber et al., 2001; Baber et al., 2005) and is practically the same as in (II) [1.735 (6) Å].

The two dimethylarene groups in molecule (I) are nearly parallel, the interplanar angle being 3.5 (1)° in both forms. These groups stack closely together in a offset face-to-face manner, with mean interplanar separations of 3.48 and 3.46 Å in the α and β forms, respectively. Similar stacking occurs between the dimethylarenes of adjacent molecules related by an inversion centre. In this case the arene planes are rigorously parallel, with interplanar separations of 3.43 Å in α-(I) and 3.39 Å in β-(I). Thus, the structure containes an infinite stacking motif, running parallel to the [011] direction.

Since the lone electron pairs of the N atoms are involved in π conjugation, the molecule of (I) contains no electronegative acceptors for strong hydrogen bonds. The N—H bonds point roughly towards the π orbitals of arene C atoms of adjacent molecules within the stack. In α-(I) there is one symmetrically independent such contact, N1—H1N···C3(-x, -y, -z), whereas in β-(I) there are two, one with the same notation and the other N3—H3N···C13(1 - x, -y, 1 - z). These H···C distances are 2.77 (1), and 2.76 (2) and 2.76 (2) Å, respectively. Rowland & Taylor (1996) estimated the standard van der Waals H···C separation as 3.02 Å, using H-atom positions normalized by moving the H atom along the observed X—H bond until this bond length matched the neutron diffraction value (0.983 Å for N—H). Applying such normalization to (I) reduces the above-mentioned H···C distances to 2.67, and 2.68 and 2.66 Å, respectively, hence these contacts can be regarded as weak hydrogen bonds (Desiraju & Steiner, 1999).

Related literature top

For related literature, see: Baber et al. (2005); Brotherton (1964); Desiraju & Steiner (1999); Firinci et al. (2010); Miyaura & Suzuki (1995); Patton et al. (2001); Rowland & Taylor (1996); Weber et al. (2001).

Experimental top

Compound (I) was prepared by reaction of Me2NB(Cl)B(Cl)NMe2 with LiHNC6H3Me2-2,6, as described by Patton et al. (2001). [Crystals obtained directly, or by solvent evaporation from which solvent?]

Refinement top

All H atoms were located in difference maps. Methyl groups were refined as rigid bodies rotating around C—C or N—C bonds, with C—H = 0.98 Å. The C10H3 group in α-(I) was treated as ideally disordered. The arene H atoms were treated as riding on their C atoms, with C—H = 0.95 Å. The amino H atoms were refined with N—H distances restrained to 0.88 (2) Å. The Uiso values of the methyl H atoms were constrained to 1.5 times, and those of other H atoms to 1.2 times, the Ueq of the respective C or N atom.

Computing details top

Data collection: SMART (Bruker, 1998) for aI; SMART (Bruker, 2001) for bI. For both compounds, cell refinement: SAINT (Bruker, 2007); data reduction: SAINT (Bruker, 2007); program(s) used to solve structure: SHELXTL (Version 6.12; Sheldrick, 2008); program(s) used to refine structure: SHELXTL (Version 6.12; Sheldrick, 2008); molecular graphics: OLEX2 (Version 1.1-β+++; Dolomanov et al., 2009); software used to prepare material for publication: OLEX2 (Version 1.1-β+++; Dolomanov et al., 2009).

Figures top
[Figure 1] Fig. 1. The molecular structure of (I) in the α (top) and β (bottom) forms. Displacement ellipsoids are drawn at the 50% probability level and dashed lines indicate the minor disordered components of the methyl groups. [Please check added text] Primed atoms are generated by the crystallographic twofold axis [symmetry operator (-x + 1/2, y, -z + 1/2)].
(aI) 1,2-bis(dimethylamino)-1,2-bis(2,6-dimethylanilino)diborane top
Crystal data top
C20H32B2N4F(000) = 380
Mr = 350.12Dx = 1.100 Mg m3
Monoclinic, P2/nMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yacCell parameters from 4810 reflections
a = 10.4957 (11) Åθ = 2.6–28.9°
b = 9.6327 (10) ŵ = 0.07 mm1
c = 10.5554 (11) ÅT = 200 K
β = 98.06 (2)°Plate, colourless
V = 1056.63 (19) Å30.53 × 0.35 × 0.05 mm
Z = 2
Data collection top
Siemens SMART 1000 CCD area-detector
diffractometer
2436 independent reflections
Radiation source: fine-focus sealed tube1779 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.028
Detector resolution: 8 pixels mm-1θmax = 27.5°, θmin = 2.1°
ω scansh = 1313
Absorption correction: multi-scan
(SADABS; Sheldrick, 2006)
k = 1212
Tmin = 0.924, Tmax = 1.000l = 1313
10983 measured reflections
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.043Hydrogen site location: difference Fourier map
wR(F2) = 0.128H atoms treated by a mixture of independent and constrained refinement
S = 1.05 w = 1/[σ2(Fo2) + (0.0582P)2 + 0.1935P]
where P = (Fo2 + 2Fc2)/3
2436 reflections(Δ/σ)max < 0.001
124 parametersΔρmax = 0.28 e Å3
1 restraintΔρmin = 0.16 e Å3
Crystal data top
C20H32B2N4V = 1056.63 (19) Å3
Mr = 350.12Z = 2
Monoclinic, P2/nMo Kα radiation
a = 10.4957 (11) ŵ = 0.07 mm1
b = 9.6327 (10) ÅT = 200 K
c = 10.5554 (11) Å0.53 × 0.35 × 0.05 mm
β = 98.06 (2)°
Data collection top
Siemens SMART 1000 CCD area-detector
diffractometer
2436 independent reflections
Absorption correction: multi-scan
(SADABS; Sheldrick, 2006)
1779 reflections with I > 2σ(I)
Tmin = 0.924, Tmax = 1.000Rint = 0.028
10983 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0431 restraint
wR(F2) = 0.128H atoms treated by a mixture of independent and constrained refinement
S = 1.05Δρmax = 0.28 e Å3
2436 reflectionsΔρmin = 0.16 e Å3
124 parameters
Special details top

Experimental. The data collection nominally covered full sphere of reciprocal space, by a combination of 4 runs of narrow-frame ω-scans (scan width 0.3° ω, 20 s exposure), every run at a different ϕ angle. Crystal to detector distance 4.41 cm.

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

Refinement. Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > σ(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. Methyl groups were refined as rigid bodies rotating around C—C or N—C bonds, except C(10)H3 which was treated as ideally disordered between 2 orientations (riding model). The amino hydrogen - Only coordinates of H atoms refined with the N—H distance restrained to 0.88 (2), arene H atoms - riding model.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/UeqOcc. (<1)
N10.11688 (10)0.21137 (13)0.12955 (11)0.0417 (3)
H1N0.0336 (12)0.2042 (16)0.1103 (14)0.050*
N20.08526 (12)0.42128 (13)0.24982 (12)0.0509 (3)
C10.17641 (11)0.09284 (14)0.08258 (11)0.0351 (3)
C20.13404 (11)0.03951 (14)0.11391 (11)0.0363 (3)
C30.18564 (12)0.15600 (15)0.06326 (12)0.0427 (3)
H30.15720.24300.08460.051*
C40.27814 (13)0.14390 (18)0.01784 (13)0.0486 (4)
H40.31330.22790.05170.058*
C50.31867 (13)0.01409 (18)0.04859 (12)0.0486 (4)
H50.38230.01220.10440.058*
C60.26890 (12)0.10617 (16)0.00077 (12)0.0424 (3)
C70.03494 (12)0.05473 (16)0.20282 (12)0.0433 (3)
H7A0.01670.15340.21400.065*
H7B0.04430.00700.16640.065*
H7C0.06770.01370.28600.065*
C80.31144 (16)0.24532 (19)0.04330 (15)0.0611 (4)
H8A0.38160.28050.01960.092*
H8B0.23890.31030.05060.092*
H8C0.34160.23600.12660.092*
C90.12520 (17)0.53273 (16)0.33939 (17)0.0592 (4)
H9A0.21660.52180.37270.089*
H9B0.07430.52960.41040.089*
H9C0.11180.62220.29530.089*
C100.05069 (17)0.4308 (2)0.1985 (2)0.0774 (6)
H10A0.09210.34080.20750.116*0.50
H10B0.05970.45630.10780.116*0.50
H10C0.09180.50160.24570.116*0.50
H10D0.06550.52540.16560.116*0.50
H10E0.08060.37390.12320.116*0.50
H10F0.09410.42190.27440.116*0.50
B10.16980 (14)0.31610 (16)0.21743 (14)0.0391 (3)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
N10.0265 (5)0.0522 (7)0.0449 (6)0.0033 (5)0.0007 (4)0.0041 (5)
N20.0400 (6)0.0517 (7)0.0587 (7)0.0077 (5)0.0009 (5)0.0089 (6)
C10.0261 (6)0.0500 (8)0.0276 (5)0.0015 (5)0.0023 (4)0.0013 (5)
C20.0272 (6)0.0532 (8)0.0270 (5)0.0011 (5)0.0012 (4)0.0001 (5)
C30.0375 (7)0.0495 (8)0.0393 (7)0.0027 (6)0.0010 (5)0.0012 (6)
C40.0400 (7)0.0637 (10)0.0414 (7)0.0103 (7)0.0035 (6)0.0105 (7)
C50.0316 (7)0.0804 (11)0.0347 (6)0.0035 (7)0.0082 (5)0.0050 (7)
C60.0316 (6)0.0630 (9)0.0315 (6)0.0036 (6)0.0006 (5)0.0012 (6)
C70.0341 (7)0.0608 (9)0.0347 (6)0.0016 (6)0.0040 (5)0.0033 (6)
C80.0581 (9)0.0747 (12)0.0530 (9)0.0121 (8)0.0163 (7)0.0093 (8)
C90.0604 (10)0.0481 (9)0.0690 (10)0.0055 (7)0.0086 (8)0.0092 (8)
C100.0462 (9)0.0832 (13)0.0978 (14)0.0227 (9)0.0075 (9)0.0223 (11)
B10.0352 (7)0.0439 (8)0.0379 (7)0.0009 (6)0.0040 (6)0.0034 (6)
Geometric parameters (Å, º) top
N1—C11.4237 (16)C7—H7A0.9800
N1—B11.4290 (19)C7—H7B0.9801
N1—H1N0.871 (12)C7—H7C0.9800
N2—B11.4197 (19)C8—H8A0.9803
N2—C91.453 (2)C8—H8B0.9800
N2—C101.456 (2)C8—H8C0.9798
C1—C61.4043 (17)C9—H9A0.9800
C1—C21.4049 (18)C9—H9B0.9800
C2—C31.3855 (18)C9—H9C0.9801
C2—C71.5026 (17)C10—H10A0.9800
C3—C41.3864 (19)C10—H10B0.9800
C3—H30.9283C10—H10C0.9800
C4—C51.374 (2)C10—H10D0.9800
C4—H40.9777C10—H10E0.9800
C5—C61.394 (2)C10—H10F0.9800
C5—H50.9512B1—B1i1.727 (3)
C6—C81.501 (2)
C1—N1—B1129.99 (11)C6—C8—H8C109.5
C1—N1—H1N109.3 (10)H8A—C8—H8C109.5
B1—N1—H1N119.5 (10)H8B—C8—H8C109.5
B1—N2—C9123.43 (12)N2—C9—H9A109.5
B1—N2—C10124.61 (13)N2—C9—H9B109.6
C9—N2—C10111.96 (13)H9A—C9—H9B109.5
C6—C1—C2119.99 (12)N2—C9—H9C109.3
C6—C1—N1121.37 (12)H9A—C9—H9C109.4
C2—C1—N1118.48 (11)H9B—C9—H9C109.5
C3—C2—C1119.36 (11)N2—C10—H10A109.4
C3—C2—C7120.28 (13)N2—C10—H10B109.6
C1—C2—C7120.35 (12)H10A—C10—H10B109.5
C2—C3—C4121.04 (14)N2—C10—H10C109.4
C2—C3—H3118.8H10A—C10—H10C109.5
C4—C3—H3120.2H10B—C10—H10C109.5
C5—C4—C3119.28 (13)N2—C10—H10D106.8
C5—C4—H4121.4H10A—C10—H10D143.7
C3—C4—H4119.3H10B—C10—H10D55.4
C4—C5—C6121.76 (12)H10C—C10—H10D58.2
C4—C5—H5115.6N2—C10—H10E116.9
C6—C5—H5122.7H10A—C10—H10E59.2
C5—C6—C1118.55 (13)H10B—C10—H10E51.1
C5—C6—C8119.43 (12)H10C—C10—H10E133.5
C1—C6—C8121.98 (13)H10D—C10—H10E102.5
C2—C7—H7A109.5N2—C10—H10F103.5
C2—C7—H7B109.4H10A—C10—H10F65.1
H7A—C7—H7B109.5H10B—C10—H10F146.0
C2—C7—H7C109.5H10C—C10—H10F50.0
H7A—C7—H7C109.5H10D—C10—H10F107.6
H7B—C7—H7C109.5H10E—C10—H10F118.8
C6—C8—H8A109.5N2—B1—N1117.45 (12)
C6—C8—H8B109.5N2—B1—B1i120.76 (10)
H8A—C8—H8B109.5N1—B1—B1i121.80 (10)
C6—C1—N1—B169.21 (18)N1—B1—B1i—N1i67.7 (3)
C1—N1—B1—B1i1.8 (2)N2—B1—B1i—N2ii173.69 (16)
Symmetry codes: (i) x+1/2, y, z+1/2; (ii) x, y, z.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1—H1N···C3ii0.87 (1)2.77 (1)3.5631 (18)152 (1)
Symmetry code: (ii) x, y, z.
(bI) 1,2-bis(dimethylamino)-1,2-bis(2,6-dimethylanilino)diborane top
Crystal data top
C20H32B2N4Z = 2
Mr = 350.12F(000) = 380
Triclinic, P1Dx = 1.113 Mg m3
Hall symbol: -P 1Mo Kα radiation, λ = 0.71073 Å
a = 10.5043 (13) ÅCell parameters from 3491 reflections
b = 9.6449 (11) Åθ = 2.6–27.4°
c = 10.4428 (14) ŵ = 0.07 mm1
α = 92.69 (3)°T = 120 K
β = 98.29 (3)°Plate, colourless
γ = 87.45 (3)°0.52 × 0.21 × 0.02 mm
V = 1045.0 (2) Å3
Data collection top
Bruker SMART 6000 CCD area-detector
diffractometer
3693 independent reflections
Radiation source: fine-focus sealed tube2774 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.027
Detector resolution: 5.6 pixels mm-1θmax = 25.0°, θmin = 2.0°
ω scansh = 1212
Absorption correction: multi-scan
(SADABS; Sheldrick, 2006)
k = 1111
Tmin = 0.715, Tmax = 0.862l = 1212
9870 measured reflections
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.053Hydrogen site location: difference Fourier map
wR(F2) = 0.150H atoms treated by a mixture of independent and constrained refinement
S = 1.05 w = 1/[σ2(Fo2) + (0.0806P)2 + 0.3393P]
where P = (Fo2 + 2Fc2)/3
3693 reflections(Δ/σ)max < 0.001
249 parametersΔρmax = 0.35 e Å3
2 restraintsΔρmin = 0.24 e Å3
Crystal data top
C20H32B2N4γ = 87.45 (3)°
Mr = 350.12V = 1045.0 (2) Å3
Triclinic, P1Z = 2
a = 10.5043 (13) ÅMo Kα radiation
b = 9.6449 (11) ŵ = 0.07 mm1
c = 10.4428 (14) ÅT = 120 K
α = 92.69 (3)°0.52 × 0.21 × 0.02 mm
β = 98.29 (3)°
Data collection top
Bruker SMART 6000 CCD area-detector
diffractometer
3693 independent reflections
Absorption correction: multi-scan
(SADABS; Sheldrick, 2006)
2774 reflections with I > 2σ(I)
Tmin = 0.715, Tmax = 0.862Rint = 0.027
9870 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0532 restraints
wR(F2) = 0.150H atoms treated by a mixture of independent and constrained refinement
S = 1.05Δρmax = 0.35 e Å3
3693 reflectionsΔρmin = 0.24 e Å3
249 parameters
Special details top

Experimental. The data collection nominally covered full sphere of reciprocal space, by a combination of 3 runs of narrow-frame ω-scans (scan width 0.3° ω, 20 s exposure), every run at a different ϕ angle. Crystal to detector distance 4.84 cm. Non-standard lattice setting has been chosen for compatibility with the high-temperature (monoclinic) phase.

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

Refinement. Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > σ(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. Methyl groups were refined as rigid bodies rotating around C—C and N—C bonds, with a common refined U for three H atoms. Amino H atoms: All H-atom parameters refined, other H atoms: riding model. Pseudo-monoclinic structure: can be solved refined in the same setting in space group P2/n (unique axis x) to R_factor_gt = 0.125 (Rint=0.255).

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
N10.11739 (14)0.21129 (16)0.12804 (15)0.0268 (4)
H1N0.0330 (15)0.204 (2)0.114 (2)0.032*
N20.08770 (15)0.43091 (17)0.24840 (16)0.0349 (4)
N30.38539 (15)0.20932 (16)0.36845 (15)0.0271 (4)
H3N0.4688 (15)0.197 (2)0.384 (2)0.033*
N40.41607 (15)0.41466 (17)0.25001 (16)0.0334 (4)
C10.17717 (16)0.08764 (19)0.08130 (17)0.0246 (4)
C20.13456 (16)0.04100 (19)0.11355 (16)0.0237 (4)
C30.18637 (17)0.16287 (19)0.06220 (17)0.0272 (4)
H30.15790.24990.08350.033*
C40.27892 (18)0.1596 (2)0.01945 (18)0.0297 (4)
H40.31410.24360.05330.036*
C50.31965 (17)0.0333 (2)0.05121 (17)0.0294 (4)
H50.38330.03140.10710.035*
C60.26959 (17)0.0919 (2)0.00312 (17)0.0270 (4)
C70.03569 (17)0.0458 (2)0.20329 (17)0.0278 (4)
H7A0.01700.14270.21470.042*
H7B0.04330.00430.16640.042*
H7C0.06890.00220.28740.042*
C80.3125 (2)0.2270 (2)0.0464 (2)0.0361 (5)
H8A0.38370.26110.01670.054*
H8B0.24050.29570.05270.054*
H8C0.34140.21180.13120.054*
C90.1286 (2)0.5437 (2)0.3398 (2)0.0381 (5)
H9A0.21960.52830.37450.057*
H9B0.07680.54730.41090.057*
H9C0.11700.63170.29560.057*
C100.0482 (2)0.4461 (3)0.1969 (3)0.0541 (7)
H10A0.06790.38070.12270.081*
H10B0.06810.54120.16890.081*
H10C0.10030.42650.26410.081*
C110.32536 (16)0.09702 (19)0.41676 (16)0.0240 (4)
C120.36720 (16)0.03945 (19)0.38587 (16)0.0239 (4)
C130.31468 (17)0.1498 (2)0.43824 (17)0.0284 (4)
H130.34270.24220.41790.034*
C140.22198 (18)0.1273 (2)0.52044 (19)0.0330 (5)
H140.18640.20350.55540.040*
C150.18238 (18)0.0064 (2)0.54993 (18)0.0327 (5)
H150.11880.02180.60570.039*
C160.23309 (17)0.1209 (2)0.50054 (17)0.0286 (4)
C170.46603 (17)0.0656 (2)0.29656 (17)0.0282 (4)
H17A0.48610.16550.28830.042*
H17B0.54440.01730.33180.042*
H17C0.43220.03070.21120.042*
C180.1909 (2)0.2647 (2)0.5425 (2)0.0408 (5)
H18A0.12090.29990.47830.061*
H18B0.26360.32620.54970.061*
H18C0.16050.26190.62670.061*
C190.3758 (2)0.5234 (2)0.1595 (2)0.0381 (5)
H19A0.28500.51340.12360.057*
H19B0.42840.51560.08910.057*
H19C0.38670.61450.20450.057*
C200.5512 (2)0.4227 (3)0.3048 (2)0.0470 (6)
H20A0.60440.41560.23480.070*
H20B0.57510.34640.36330.070*
H20C0.56500.51160.35310.070*
B10.1714 (2)0.3186 (2)0.2162 (2)0.0268 (5)
B20.3320 (2)0.3137 (2)0.2816 (2)0.0262 (5)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
N10.0182 (8)0.0331 (9)0.0275 (8)0.0020 (6)0.0011 (6)0.0001 (7)
N20.0275 (9)0.0354 (9)0.0375 (10)0.0061 (7)0.0048 (7)0.0066 (7)
N30.0177 (8)0.0334 (9)0.0289 (8)0.0010 (6)0.0017 (6)0.0024 (7)
N40.0277 (9)0.0345 (9)0.0366 (9)0.0036 (7)0.0025 (7)0.0076 (7)
C10.0198 (9)0.0323 (10)0.0192 (9)0.0021 (7)0.0044 (7)0.0015 (7)
C20.0176 (9)0.0341 (10)0.0174 (8)0.0005 (7)0.0047 (7)0.0014 (7)
C30.0248 (9)0.0305 (10)0.0242 (9)0.0012 (7)0.0037 (8)0.0006 (8)
C40.0255 (10)0.0378 (11)0.0235 (9)0.0060 (8)0.0004 (8)0.0040 (8)
C50.0218 (9)0.0462 (12)0.0194 (9)0.0019 (8)0.0024 (7)0.0014 (8)
C60.0216 (9)0.0383 (11)0.0191 (9)0.0009 (7)0.0036 (7)0.0020 (8)
C70.0235 (9)0.0371 (10)0.0220 (9)0.0011 (7)0.0001 (7)0.0023 (8)
C80.0349 (11)0.0426 (12)0.0321 (11)0.0022 (9)0.0076 (9)0.0051 (9)
C90.0390 (12)0.0322 (11)0.0412 (12)0.0033 (8)0.0023 (9)0.0048 (9)
C100.0324 (12)0.0549 (15)0.0668 (16)0.0168 (10)0.0092 (11)0.0177 (12)
C110.0193 (9)0.0341 (10)0.0167 (8)0.0012 (7)0.0044 (7)0.0022 (7)
C120.0182 (9)0.0347 (10)0.0168 (8)0.0026 (7)0.0048 (7)0.0012 (7)
C130.0251 (10)0.0332 (10)0.0249 (9)0.0014 (8)0.0034 (8)0.0023 (8)
C140.0278 (10)0.0444 (12)0.0266 (10)0.0098 (8)0.0018 (8)0.0087 (9)
C150.0204 (9)0.0566 (13)0.0212 (9)0.0006 (8)0.0029 (7)0.0029 (9)
C160.0205 (9)0.0422 (11)0.0208 (9)0.0021 (8)0.0029 (7)0.0002 (8)
C170.0229 (9)0.0369 (11)0.0236 (9)0.0001 (8)0.0004 (7)0.0003 (8)
C180.0378 (12)0.0506 (13)0.0336 (11)0.0092 (10)0.0092 (9)0.0039 (10)
C190.0414 (12)0.0316 (11)0.0412 (12)0.0025 (9)0.0040 (10)0.0053 (9)
C200.0301 (11)0.0531 (14)0.0569 (15)0.0127 (10)0.0030 (10)0.0121 (11)
B10.0266 (11)0.0289 (11)0.0246 (10)0.0014 (8)0.0024 (8)0.0030 (9)
B20.0262 (11)0.0286 (11)0.0227 (10)0.0006 (8)0.0022 (8)0.0033 (8)
Geometric parameters (Å, º) top
N1—C11.422 (2)C9—H9B0.9798
N1—B11.433 (3)C9—H9C0.9797
N1—H1N0.883 (15)C10—H10A0.9796
N2—B11.423 (3)C10—H10B0.9801
N2—C91.450 (3)C10—H10C0.9798
N2—C101.455 (3)C11—C161.401 (3)
N3—C111.424 (2)C11—C121.407 (3)
N3—B21.428 (3)C12—C131.390 (3)
N3—H3N0.871 (15)C12—C171.498 (3)
N4—B21.424 (3)C13—C141.392 (3)
N4—C191.453 (3)C13—H130.9501
N4—C201.456 (3)C14—C151.372 (3)
C1—C61.405 (3)C14—H140.9500
C1—C21.409 (3)C15—C161.398 (3)
C2—C31.390 (3)C15—H150.9502
C2—C71.499 (3)C16—C181.503 (3)
C3—C41.385 (3)C17—H17A0.9799
C3—H30.9501C17—H17B0.9799
C4—C51.379 (3)C17—H17C0.9799
C4—H40.9500C18—H18A0.9802
C5—C61.396 (3)C18—H18B0.9799
C5—H50.9499C18—H18C0.9802
C6—C81.507 (3)C19—H19A0.9802
C7—H7A0.9797C19—H19B0.9800
C7—H7B0.9800C19—H19C0.9803
C7—H7C0.9802C20—H20A0.9800
C8—H8A0.9800C20—H20B0.9800
C8—H8B0.9801C20—H20C0.9800
C8—H8C0.9802B1—B21.726 (3)
C9—H9A0.9801
C1—N1—B1129.55 (15)N2—C10—H10C109.5
C1—N1—H1N109.4 (13)H10A—C10—H10C109.5
B1—N1—H1N119.0 (13)H10B—C10—H10C109.4
B1—N2—C9123.34 (16)C16—C11—C12120.23 (17)
B1—N2—C10124.88 (17)C16—C11—N3121.16 (17)
C9—N2—C10111.77 (16)C12—C11—N3118.46 (16)
C11—N3—B2129.98 (16)C13—C12—C11119.12 (17)
C11—N3—H3N109.8 (13)C13—C12—C17120.40 (17)
B2—N3—H3N118.8 (14)C11—C12—C17120.48 (16)
B2—N4—C19123.48 (16)C12—C13—C14121.09 (18)
B2—N4—C20124.54 (17)C12—C13—H13119.5
C19—N4—C20111.98 (17)C14—C13—H13119.4
C6—C1—C2120.10 (17)C15—C14—C13119.12 (18)
C6—C1—N1121.36 (17)C15—C14—H14120.5
C2—C1—N1118.36 (16)C13—C14—H14120.4
C3—C2—C1119.14 (17)C14—C15—C16121.92 (18)
C3—C2—C7120.66 (17)C14—C15—H15119.2
C1—C2—C7120.20 (16)C16—C15—H15118.9
C4—C3—C2121.10 (17)C15—C16—C11118.51 (18)
C4—C3—H3119.4C15—C16—C18119.23 (18)
C2—C3—H3119.5C11—C16—C18122.22 (18)
C5—C4—C3119.46 (17)C12—C17—H17A109.7
C5—C4—H4120.3C12—C17—H17B109.3
C3—C4—H4120.3H17A—C17—H17B109.5
C4—C5—C6121.56 (18)C12—C17—H17C109.4
C4—C5—H5119.2H17A—C17—H17C109.5
C6—C5—H5119.2H17B—C17—H17C109.5
C5—C6—C1118.63 (17)C16—C18—H18A109.5
C5—C6—C8119.36 (17)C16—C18—H18B109.5
C1—C6—C8121.98 (17)H18A—C18—H18B109.5
C2—C7—H7A109.4C16—C18—H18C109.4
C2—C7—H7B109.5H18A—C18—H18C109.5
H7A—C7—H7B109.5H18B—C18—H18C109.5
C2—C7—H7C109.4N4—C19—H19A109.5
H7A—C7—H7C109.5N4—C19—H19B109.4
H7B—C7—H7C109.5H19A—C19—H19B109.5
C6—C8—H8A109.4N4—C19—H19C109.6
C6—C8—H8B109.6H19A—C19—H19C109.5
H8A—C8—H8B109.5H19B—C19—H19C109.5
C6—C8—H8C109.3N4—C20—H20A109.5
H8A—C8—H8C109.5N4—C20—H20B109.5
H8B—C8—H8C109.5H20A—C20—H20B109.5
N2—C9—H9A109.4N4—C20—H20C109.5
N2—C9—H9B109.6H20A—C20—H20C109.5
H9A—C9—H9B109.5H20B—C20—H20C109.5
N2—C9—H9C109.4N2—B1—N1117.63 (17)
H9A—C9—H9C109.5N2—B1—B2120.61 (16)
H9B—C9—H9C109.5N1—B1—B2121.76 (16)
N2—C10—H10A109.3N4—B2—N3117.68 (17)
N2—C10—H10B109.6N4—B2—B1120.63 (16)
H10A—C10—H10B109.4N3—B2—B1121.69 (17)
C2—C1—N1—B1116.0 (2)B2—N3—C11—C12117.3 (2)
C1—N1—B1—B21.3 (3)C6—C1—N1—B168.8 (3)
N1—B1—B2—N366.0 (2)C16—C11—N2—B2149.46 (15)
B1—B2—N3—C110.2 (3)N3—B1—B2—N4180.0 (3)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1—H1N···C3i0.88 (2)2.76 (2)3.544 (2)148 (2)
N3—H3N···C13ii0.87 (2)2.76 (2)3.528 (3)148 (2)
Symmetry codes: (i) x, y, z; (ii) x+1, y, z+1.

Experimental details

(aI)(bI)
Crystal data
Chemical formulaC20H32B2N4C20H32B2N4
Mr350.12350.12
Crystal system, space groupMonoclinic, P2/nTriclinic, P1
Temperature (K)200120
a, b, c (Å)10.4957 (11), 9.6327 (10), 10.5554 (11)10.5043 (13), 9.6449 (11), 10.4428 (14)
α, β, γ (°)90, 98.06 (2), 9092.69 (3), 98.29 (3), 87.45 (3)
V3)1056.63 (19)1045.0 (2)
Z22
Radiation typeMo KαMo Kα
µ (mm1)0.070.07
Crystal size (mm)0.53 × 0.35 × 0.050.52 × 0.21 × 0.02
Data collection
DiffractometerSiemens SMART 1000 CCD area-detector
diffractometer
Bruker SMART 6000 CCD area-detector
diffractometer
Absorption correctionMulti-scan
(SADABS; Sheldrick, 2006)
Multi-scan
(SADABS; Sheldrick, 2006)
Tmin, Tmax0.924, 1.0000.715, 0.862
No. of measured, independent and
observed [I > 2σ(I)] reflections
10983, 2436, 1779 9870, 3693, 2774
Rint0.0280.027
(sin θ/λ)max1)0.6490.595
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.043, 0.128, 1.05 0.053, 0.150, 1.05
No. of reflections24363693
No. of parameters124249
No. of restraints12
H-atom treatmentH atoms treated by a mixture of independent and constrained refinementH atoms treated by a mixture of independent and constrained refinement
Δρmax, Δρmin (e Å3)0.28, 0.160.35, 0.24

Computer programs: SMART (Bruker, 1998), SMART (Bruker, 2001), SAINT (Bruker, 2007), SHELXTL (Version 6.12; Sheldrick, 2008), OLEX2 (Version 1.1-β+++; Dolomanov et al., 2009).

Selected bond lengths (Å) for (aI) top
N1—C11.4237 (16)N2—B11.4197 (19)
N1—B11.4290 (19)B1—B1i1.727 (3)
Symmetry code: (i) x+1/2, y, z+1/2.
Hydrogen-bond geometry (Å, º) for (aI) top
D—H···AD—HH···AD···AD—H···A
N1—H1N···C3ii0.871 (12)2.773 (13)3.5631 (18)151.6 (13)
Symmetry code: (ii) x, y, z.
Selected bond lengths (Å) for (bI) top
N1—C11.422 (2)N3—B21.428 (3)
N1—B11.433 (3)N4—B21.424 (3)
N2—B11.423 (3)B1—B21.726 (3)
N3—C111.424 (2)
Hydrogen-bond geometry (Å, º) for (bI) top
D—H···AD—HH···AD···AD—H···A
N1—H1N···C3i0.883 (15)2.763 (17)3.544 (2)148.3 (17)
N3—H3N···C13ii0.871 (15)2.757 (17)3.528 (3)148.3 (17)
Symmetry codes: (i) x, y, z; (ii) x+1, y, z+1.
 

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