The factors influencing the distortion of inorganic anions in the structures of chloridoantimonates(III) with organic cations, in spite of numerous structural studies on those compounds, have not been clearly described and separated. The title compound, [(C
2H
5)
2NH
2]
3[SbCl
6], consisting of isolated distorted [SbCl
6]
3− octahedra that have
C3 symmetry and [(C
2H
5)
2NH
2]
+ cations, unequivocally shows the role played by hydrogen bonding in the geometry variations of inorganic anions. The organic cations, which are linked to the inorganic substructure through N—H
Cl hydrogen bonds, are clearly responsible for the distortion of the octahedral coordination of Sb
III in terms of differences (Δ) in both Sb—Cl bond lengths [Δ = 0.4667 (6) Å] and Cl—Sb—Cl angles [Δ = 9.651 (17)°].
Supporting information
CCDC reference: 774880
SbCl3 (2.28 g, 1 mmol) dissolved in 6 M HCl (6 ml) was treated with
(C2H5)2NH (5.2 ml, 5 mmol) added slowly, dropwise, with stirring, to 6
M HCl (10 ml). Slow evaporation of the acid solution at room
temperature yielded transparent, colourless crystals of
[(C2H5)2NH2]3[SbCl6].
All H atoms were located in Fourier difference maps, refined with C—H
distances constrained (methyl groups allowed rotational freedom) and
Ueq values for –CH3 and >CH2, equal to 1.5 and 1.2 times the
Ueq value of their carriers, respectively. The >NH2+ group H-atom
parameters were refined freely. The absolute structure is determined
reliably.
Data collection: CrysAlis CCD (Oxford Diffraction, 2009); cell refinement: CrysAlis PRO (Oxford Diffraction, 2009); data reduction: CrysAlis PRO (Oxford Diffraction, 2009); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: Mercury (Macrae et al., 2008); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).
Tris(diethylammonium) hexachloridoantimonate(III)
top
Crystal data top
(C4H12N)3[SbCl6] | Dx = 1.559 Mg m−3 |
Mr = 556.90 | Mo Kα radiation, λ = 0.71073 Å |
Trigonal, R3c | Cell parameters from 8381 reflections |
Hall symbol: R 3 -2"c | θ = 2.8–29.7° |
a = 14.71917 (18) Å | µ = 1.84 mm−1 |
c = 18.9694 (3) Å | T = 85 K |
V = 3559.19 (8) Å3 | Tabular, colourless |
Z = 6 | 0.19 × 0.19 × 0.15 mm |
F(000) = 1692 | |
Data collection top
Oxford Diffraction Xcalibur diffractometer | 2056 independent reflections |
Radiation source: fine-focus sealed tube | 2018 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.012 |
ω–scan | θmax = 29.5°, θmin = 2.7° |
Absorption correction: analytical CrysAlis RED (Oxford Diffraction, 2009); analytical numeric absorption
correction using a multifaceted crystal
model based on expressions derived by Clark & Reid (1995) | h = −20→18 |
Tmin = 0.713, Tmax = 0.760 | k = −14→20 |
9101 measured reflections | l = −26→25 |
Refinement top
Refinement on F2 | Secondary atom site location: difference Fourier map |
Least-squares matrix: full | Hydrogen site location: difference Fourier map |
R[F2 > 2σ(F2)] = 0.008 | H atoms treated by a mixture of independent and constrained refinement |
wR(F2) = 0.030 | w = 1/[σ2(Fo2) + (0.0038P)2 + 4.6787P] where P = (Fo2 + 2Fc2)/3 |
S = 1.48 | (Δ/σ)max < 0.001 |
2056 reflections | Δρmax = 0.53 e Å−3 |
78 parameters | Δρmin = −0.54 e Å−3 |
1 restraint | Absolute structure: Flack (1983), 973 Friedel pairs |
Primary atom site location: heavy-atom method | Absolute structure parameter: 0.001 (16) |
Crystal data top
(C4H12N)3[SbCl6] | Z = 6 |
Mr = 556.90 | Mo Kα radiation |
Trigonal, R3c | µ = 1.84 mm−1 |
a = 14.71917 (18) Å | T = 85 K |
c = 18.9694 (3) Å | 0.19 × 0.19 × 0.15 mm |
V = 3559.19 (8) Å3 | |
Data collection top
Oxford Diffraction Xcalibur diffractometer | 2056 independent reflections |
Absorption correction: analytical CrysAlis RED (Oxford Diffraction, 2009); analytical numeric absorption
correction using a multifaceted crystal
model based on expressions derived by Clark & Reid (1995) | 2018 reflections with I > 2σ(I) |
Tmin = 0.713, Tmax = 0.760 | Rint = 0.012 |
9101 measured reflections | |
Refinement top
R[F2 > 2σ(F2)] = 0.008 | H atoms treated by a mixture of independent and constrained refinement |
wR(F2) = 0.030 | Δρmax = 0.53 e Å−3 |
S = 1.48 | Δρmin = −0.54 e Å−3 |
2056 reflections | Absolute structure: Flack (1983), 973 Friedel pairs |
78 parameters | Absolute structure parameter: 0.001 (16) |
1 restraint | |
Special details top
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. |
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. R-factors
based on F2 are statistically about twice as large as those based on
F, and R- factors based on ALL data will be even larger. |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | |
Sb1 | 0.0000 | 0.0000 | −0.000139 (14) | 0.00777 (4) | |
Cl1 | 0.01743 (3) | 0.14641 (3) | 0.07349 (2) | 0.01389 (8) | |
Cl2 | 0.16498 (3) | 0.16960 (3) | −0.08459 (2) | 0.01228 (8) | |
N1 | 0.29887 (12) | 0.22044 (12) | 0.35085 (8) | 0.0114 (3) | |
H1 | 0.2657 (17) | 0.1554 (17) | 0.3647 (10) | 0.010 (5)* | |
H2 | 0.360 (2) | 0.241 (2) | 0.3335 (13) | 0.028 (7)* | |
C1 | 0.31842 (15) | 0.28205 (13) | 0.41751 (11) | 0.0151 (3) | |
H11 | 0.3513 | 0.2576 | 0.4526 | 0.018* | |
H12 | 0.2505 | 0.2689 | 0.4370 | 0.018* | |
C2 | 0.38888 (14) | 0.39873 (14) | 0.40580 (10) | 0.0176 (4) | |
H21 | 0.4579 | 0.4126 | 0.3896 | 0.026* | |
H22 | 0.3967 | 0.4362 | 0.4501 | 0.026* | |
H23 | 0.3576 | 0.4229 | 0.3701 | 0.026* | |
C3 | 0.22999 (14) | 0.23397 (14) | 0.29888 (9) | 0.0146 (3) | |
H31 | 0.2693 | 0.3043 | 0.2770 | 0.018* | |
H32 | 0.1684 | 0.2290 | 0.3236 | 0.018* | |
C4 | 0.19323 (15) | 0.15046 (15) | 0.24191 (10) | 0.0191 (4) | |
H41 | 0.2542 | 0.1562 | 0.2170 | 0.029* | |
H42 | 0.1482 | 0.1604 | 0.2085 | 0.029* | |
H43 | 0.1536 | 0.0809 | 0.2635 | 0.029* | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
Sb1 | 0.00776 (5) | 0.00776 (5) | 0.00778 (6) | 0.00388 (2) | 0.000 | 0.000 |
Cl1 | 0.01554 (19) | 0.01321 (19) | 0.01340 (18) | 0.00755 (16) | 0.00087 (16) | −0.00293 (15) |
Cl2 | 0.01352 (18) | 0.01190 (18) | 0.01190 (17) | 0.00670 (16) | 0.00194 (15) | −0.00073 (15) |
N1 | 0.0091 (7) | 0.0099 (7) | 0.0145 (7) | 0.0042 (6) | 0.0015 (5) | 0.0017 (5) |
C1 | 0.0160 (9) | 0.0183 (8) | 0.0121 (7) | 0.0094 (8) | 0.0011 (7) | −0.0010 (8) |
C2 | 0.0180 (9) | 0.0170 (9) | 0.0183 (9) | 0.0090 (7) | −0.0006 (7) | −0.0046 (7) |
C3 | 0.0148 (8) | 0.0157 (8) | 0.0144 (8) | 0.0084 (7) | 0.0004 (7) | 0.0027 (7) |
C4 | 0.0213 (9) | 0.0173 (9) | 0.0161 (8) | 0.0077 (8) | −0.0023 (7) | 0.0002 (7) |
Geometric parameters (Å, º) top
Sb1—Cl1 | 2.4715 (4) | C1—H12 | 0.9900 |
Sb1—Cl2 | 2.9382 (4) | C2—H21 | 0.9800 |
N1—C1 | 1.498 (2) | C2—H22 | 0.9800 |
N1—C3 | 1.497 (2) | C2—H23 | 0.9800 |
C1—C2 | 1.514 (2) | C3—H31 | 0.9900 |
C3—C4 | 1.519 (3) | C3—H32 | 0.9900 |
N1—H1 | 0.87 (2) | C4—H41 | 0.9800 |
N1—H2 | 0.85 (3) | C4—H42 | 0.9800 |
C1—H11 | 0.9900 | C4—H43 | 0.9800 |
| | | |
Cl1—Sb1—Cl1i | 91.200 (16) | C1—C2—H21 | 109.5 |
Cl1—Sb1—Cl2 | 83.450 (12) | C1—C2—H22 | 109.5 |
Cl1—Sb1—Cl2i | 173.514 (13) | H21—C2—H22 | 109.5 |
Cl1i—Sb1—Cl2 | 92.570 (13) | C1—C2—H23 | 109.5 |
Cl2i—Sb1—Cl2 | 93.101 (12) | H21—C2—H23 | 109.5 |
N1—C1—C2 | 112.22 (16) | H22—C2—H23 | 109.5 |
N1—C3—C4 | 110.60 (14) | N1—C3—H31 | 109.5 |
C1—N1—C3 | 114.41 (14) | C4—C3—H31 | 109.5 |
C3—N1—H1 | 107.4 (14) | N1—C3—H32 | 109.5 |
C1—N1—H1 | 104.1 (13) | C4—C3—H32 | 109.5 |
C3—N1—H2 | 111.1 (16) | H31—C3—H32 | 108.1 |
C1—N1—H2 | 105.3 (17) | C3—C4—H41 | 109.5 |
H1—N1—H2 | 115 (2) | C3—C4—H42 | 109.5 |
N1—C1—H11 | 109.2 | H41—C4—H42 | 109.5 |
C2—C1—H11 | 109.2 | C3—C4—H43 | 109.5 |
N1—C1—H12 | 109.2 | H41—C4—H43 | 109.5 |
C2—C1—H12 | 109.2 | H42—C4—H43 | 109.5 |
H11—C1—H12 | 107.9 | | |
| | | |
C3—N1—C1—C2 | −70.72 (19) | C1—N1—C3—C4 | −166.34 (15) |
Symmetry code: (i) −x+y, −x, z. |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1···Cl2ii | 0.87 (2) | 2.28 (2) | 3.135 (2) | 170 (2) |
N1—H2···Cl2iii | 0.85 (3) | 2.39 (3) | 3.186 (2) | 154 (2) |
Symmetry codes: (ii) x, x−y, z+1/2; (iii) −y+2/3, x−y+1/3, z+1/3. |
Experimental details
Crystal data |
Chemical formula | (C4H12N)3[SbCl6] |
Mr | 556.90 |
Crystal system, space group | Trigonal, R3c |
Temperature (K) | 85 |
a, c (Å) | 14.71917 (18), 18.9694 (3) |
V (Å3) | 3559.19 (8) |
Z | 6 |
Radiation type | Mo Kα |
µ (mm−1) | 1.84 |
Crystal size (mm) | 0.19 × 0.19 × 0.15 |
|
Data collection |
Diffractometer | Oxford Diffraction Xcalibur diffractometer |
Absorption correction | Analytical CrysAlis RED (Oxford Diffraction, 2009); analytical numeric absorption
correction using a multifaceted crystal
model based on expressions derived by Clark & Reid (1995) |
Tmin, Tmax | 0.713, 0.760 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 9101, 2056, 2018 |
Rint | 0.012 |
(sin θ/λ)max (Å−1) | 0.692 |
|
Refinement |
R[F2 > 2σ(F2)], wR(F2), S | 0.008, 0.030, 1.48 |
No. of reflections | 2056 |
No. of parameters | 78 |
No. of restraints | 1 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.53, −0.54 |
Absolute structure | Flack (1983), 973 Friedel pairs |
Absolute structure parameter | 0.001 (16) |
Selected geometric parameters (Å, º) topSb1—Cl1 | 2.4715 (4) | N1—C3 | 1.497 (2) |
Sb1—Cl2 | 2.9382 (4) | C1—C2 | 1.514 (2) |
N1—C1 | 1.498 (2) | C3—C4 | 1.519 (3) |
| | | |
Cl1—Sb1—Cl1i | 91.200 (16) | Cl2i—Sb1—Cl2 | 93.101 (12) |
Cl1—Sb1—Cl2 | 83.450 (12) | N1—C1—C2 | 112.22 (16) |
Cl1—Sb1—Cl2i | 173.514 (13) | N1—C3—C4 | 110.60 (14) |
Cl1i—Sb1—Cl2 | 92.570 (13) | C1—N1—C3 | 114.41 (14) |
Symmetry code: (i) −x+y, −x, z. |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1···Cl2ii | 0.87 (2) | 2.28 (2) | 3.135 (2) | 170 (2) |
N1—H2···Cl2iii | 0.85 (3) | 2.39 (3) | 3.186 (2) | 154 (2) |
Symmetry codes: (ii) x, x−y, z+1/2; (iii) −y+2/3, x−y+1/3, z+1/3. |
Chloroantimonates(III) with organic cations are considered as organic–inorganic perovskite-like hybrid materials. They consist of organic cations within anionic inorganic substructures. The interest in this group of compounds is focused on two areas: (a) the structural phase transitions, some of them to polar phases, which mainly arise from the large polarizability of the complex anions, changes in the dynamic disorder of the organic cations and consequent changes in the hydrogen-bonding scheme; (b) the complex crystal chemistry – the inorganic chloroantimonate(III) anions may assume several structural geometries with varying degrees of distortion depending on the size, shape and ability to form hydrogen bonds to the organic cations (Fischer & Norman, 1994; Sobczyk et al., 1997; Mitzi, 2001; Bujak & Angel, 2005, 2006). The distortion of chloroantimonate(III) inorganic units is associated with the presence of the lone pair of electrons on the SbIII central atom (Wang & Liebau, 1996). This distortion has been correlated to a 'primary deformation', connected with the tendency of [SbCl6]3- octahedra and [SbCl5]2- square pyramids to share Cl atoms with each other in forming more complicted arrangements, and a 'secondary deformation', resulting from the presence of interactions between oppositely charged organic and inorganic components of the structures (Bujak & Zaleski, 2001, 2002).
Tris(diethylammonium) hexachoridooantimonate(III), [(C2H5)2NH2]3[SbCl6], (I), is a perfect model structure for understanding and separating the factors influencing distortion of inorganic polyhedra in chloroantimonates(III) because the inorganic substructure consists of single isolated units (the 'primary deformation' factor is thus eliminated), the organic cations are fully ordered, the postions of the H atoms are well defined and only one crystallographically independent Cl atom is involved in relatively strong well defined hydrogen-bonding interactions (Fig. 1). [(C2H5)2NH2]3[SbCl6], in the rhombohedral R3c space group, is isomorphous with its bismuth analogue – tris(diethylammonium) hexachloridobismuthate(III) (Lazarini, 1987; Jarraya et al., 1993). The structure of (I) consists of inorganic [SbCl6]3- octahedra and organic diethylammonium [(C2H5)2)NH2]+ cations that adopt an extended relative conformation of the ethyl groups with expected dimensions (Wahlberg, 1978). The [SbCl6]3- octahedra show C3 symmetry with three short [2.4715 (4) Å] and three longer [2.9382 (4) Å] Sb—Cl bonds, distributed mutually in a trans fashion, with a difference of 0.4667 (6) Å. The Cl—Sb—Cl angles are also significantly distorted. They range from 83.450 (12)°, the angle between the short and longer bonds, to 93.101 (12)°, the angle between the longer Sb–Cl bonds (Table 1), giving a difference of 9.651 (17)°. Although the distortion found in (I) is relatively large and somewhat unusual, it is not the first example of such large differences in Sb—Cl bond distances. A similar situation, with even larger Sb—Cl deviations was found in the structures of pentakis(benzidinediium) bis[hexachlordioantimony(III)] tetrachloride sesquihydrate (Dobrzycki & Woźniak, 2009), 2-ammonioguanidinium 2-aminoguanidinium hexachloridoantimonate(III) (Bujak et al., 2001) and diethylenetriammonium hexachloridoantimonate(III) (Vezzosi et al., 1984).
The observed differences in Sb—Cl bond lengths and Cl—Sb—Cl angles correlate well with the presence of N—H···Cl hydrogen bonds between the anionic substructure and the organic cations (Table 2 and Fig. 2). All N—H···Cl interactions are associated with the longer Sb1—Cl2 distances, causing the distortion of inorganic units from the ideal octahedral symmetry. The distortion is realised by a shift of the central SbIII atoms from the centre of the octahedra, by ca 0.1 Å, along the crystallographic c axis towards the three Cl1 atoms. Taking into account the geometrical parameters of the hydrogen bonds and their influence on the geometry of the inorganic substructure, they can be considered as a relatively strong among Sb–Cl···H–N interactions (Bruno et al., 2002; Steiner, 2002).
As expected, the distortion from ideal octahedral symmetry in (I) is more pronounced than that found in its bismuth(III) analogue, where the differences in Bi—Cl bond lengths and Cl—Bi—Cl angles are 0.288 (2) Å and 8.89 (6)°, respectively (Jarraya et al., 1993). This behaviour can be best rationalized on the basis of the valence shell electron pair repulsion model (Gillespie & Nyholm, 1957; Gillespie & Robinson, 2005), together with the electronic-distortion approach (Brown, 2002), in terms of a stereochemical activity (localization) of the lone pair of electrons along with the difference in polarizability of the central SbIII and BiIII atoms. Intermediate Sb—Cl bond lengths of 2.652 (6) and 2.6552 (3) Å are observed in the slightly distorted, isolated [SbCl6]3- octahedra in which all six Cl atoms are involved in hydrogen bonding rather than just three (Schroeder & Jacobson, 1973; Podesta & Orpen, 2005). Thus in (I), the asymmetric hydrogen-bond pattern is clearly responsible for the much longer Sb1—Cl2 distances and the pronounced angular distortion.