Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270104004007/na1645sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S0108270104004007/na1645Isup2.hkl |
CCDC reference: 226806
CrO3 (0.3 mol) and DABCO (0.1 mol) were dissolved separately in water (1.2 and 0.9 mol), and the two solutions were then mixed with cautious stirring. Crystals of the title salt were formed in the final solution by slow evaporation of water at 293 K for one week.
The H atoms of NH groups were located in difference Fourier maps and refined freely. All remaining H atoms were placed in calculated positions and allowed to ride on their parent atoms at distances of 0.97 Å, with Uiso values equal to 1.2Ueq of the parent atoms.
Data collection: SMART (Bruker, 2000); cell refinement: SMART; data reduction: SAINT (Bruker, 2000); program(s) used to solve structure: SHELXTL (Bruker, 2000); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.
C6H14N2·Cr3O10 | Z = 2 |
Mr = 430.19 | F(000) = 432.0 |
Triclinic, p1 | Dx = 2.073 Mg m−3 |
Hall symbol: -P1 | Mo Kα radiation, λ = 0.71073 Å |
a = 7.4895 (6) Å | Cell parameters from 346 reflections |
b = 9.7648 (8) Å | θ = 2.4–23.0° |
c = 10.1427 (8) Å | µ = 2.37 mm−1 |
α = 87.661 (1)° | T = 273 K |
β = 69.497 (1)° | Block, colorless |
γ = 82.771 (1)° | 0.59 × 0.58 × 0.52 mm |
V = 689.26 (10) Å3 |
Bruker SMART CCD area-detector diffractometer | 2459 independent reflections |
Radiation source: fine-focus sealed tube | 2336 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.013 |
ϕ and ω scans | θmax = 25.1°, θmin = 2.1° |
Absorption correction: multi-scan (SADABS; Bruker, 2000) | h = −8→8 |
Tmin = 0.023, Tmax = 0.026 | k = −11→11 |
5021 measured reflections | l = −12→11 |
Refinement on F2 | Secondary atom site location: difference Fourier map |
Least-squares matrix: full | Hydrogen site location: inferred from neighbouring sites |
R[F2 > 2σ(F2)] = 0.029 | H atoms treated by a mixture of independent and constrained refinement |
wR(F2) = 0.085 | w = 1/[σ2(Fo2) + (0.0519P)2 + 0.4865P] where P = (Fo2 + 2Fc2)/3 |
S = 1.07 | (Δ/σ)max < 0.001 |
2433 reflections | Δρmax = 0.42 e Å−3 |
199 parameters | Δρmin = −0.52 e Å−3 |
2 restraints | Extinction correction: SHELXL97, Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
Primary atom site location: structure-invariant direct methods | Extinction coefficient: 0.186 (6) |
C6H14N2·Cr3O10 | γ = 82.771 (1)° |
Mr = 430.19 | V = 689.26 (10) Å3 |
Triclinic, p1 | Z = 2 |
a = 7.4895 (6) Å | Mo Kα radiation |
b = 9.7648 (8) Å | µ = 2.37 mm−1 |
c = 10.1427 (8) Å | T = 273 K |
α = 87.661 (1)° | 0.59 × 0.58 × 0.52 mm |
β = 69.497 (1)° |
Bruker SMART CCD area-detector diffractometer | 2459 independent reflections |
Absorption correction: multi-scan (SADABS; Bruker, 2000) | 2336 reflections with I > 2σ(I) |
Tmin = 0.023, Tmax = 0.026 | Rint = 0.013 |
5021 measured reflections |
R[F2 > 2σ(F2)] = 0.029 | 2 restraints |
wR(F2) = 0.085 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.07 | Δρmax = 0.42 e Å−3 |
2433 reflections | Δρmin = −0.52 e Å−3 |
199 parameters |
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. 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. |
x | y | z | Uiso*/Ueq | ||
Cr2 | 0.02080 (5) | 0.45643 (4) | 0.21561 (4) | 0.02838 (17) | |
Cr3 | 0.30300 (6) | 0.30658 (4) | 0.37196 (4) | 0.02964 (17) | |
Cr1 | −0.07210 (6) | 0.16487 (4) | 0.14729 (5) | 0.03309 (18) | |
O8 | 0.4507 (3) | 0.2710 (2) | 0.2171 (2) | 0.0409 (5) | |
O10 | 0.3985 (3) | 0.3938 (2) | 0.4566 (2) | 0.0465 (5) | |
O9 | 0.2345 (4) | 0.1677 (2) | 0.4531 (2) | 0.0532 (6) | |
O7 | 0.0963 (3) | 0.4152 (2) | 0.3556 (2) | 0.0441 (5) | |
O5 | 0.2028 (3) | 0.4531 (2) | 0.0762 (2) | 0.0482 (5) | |
O6 | −0.0865 (3) | 0.6099 (2) | 0.2405 (3) | 0.0506 (6) | |
O4 | −0.1324 (3) | 0.3461 (2) | 0.2050 (2) | 0.0460 (5) | |
O2 | 0.1546 (3) | 0.1210 (2) | 0.1131 (3) | 0.0479 (5) | |
O1 | −0.1305 (4) | 0.1478 (3) | 0.0133 (3) | 0.0659 (8) | |
O3 | −0.1940 (4) | 0.0766 (3) | 0.2766 (3) | 0.0676 (7) | |
N1 | 0.5373 (3) | 0.2812 (2) | 0.6585 (2) | 0.0344 (5) | |
N2 | 0.6741 (3) | 0.1367 (2) | 0.8140 (2) | 0.0327 (5) | |
C1 | 0.7511 (5) | 0.2565 (4) | 0.5888 (3) | 0.0498 (8) | |
H1A | 0.8064 | 0.3421 | 0.5839 | 0.060* | |
H1B | 0.7839 | 0.2224 | 0.4937 | 0.060* | |
C2 | 0.8298 (4) | 0.1506 (3) | 0.6751 (3) | 0.0429 (7) | |
H2A | 0.8691 | 0.0624 | 0.6265 | 0.052* | |
H2B | 0.9406 | 0.1808 | 0.6889 | 0.052* | |
C3 | 0.4566 (5) | 0.1482 (3) | 0.6822 (4) | 0.0530 (8) | |
H3A | 0.5034 | 0.0952 | 0.5954 | 0.064* | |
H3B | 0.3177 | 0.1645 | 0.7123 | 0.064* | |
C4 | 0.5166 (4) | 0.0682 (3) | 0.7948 (3) | 0.0433 (7) | |
H4A | 0.4084 | 0.0694 | 0.8824 | 0.052* | |
H4B | 0.5620 | −0.0271 | 0.7655 | 0.052* | |
C5 | 0.4894 (4) | 0.3539 (3) | 0.7944 (3) | 0.0396 (6) | |
H5A | 0.3521 | 0.3612 | 0.8450 | 0.047* | |
H5B | 0.5266 | 0.4465 | 0.7774 | 0.047* | |
C6 | 0.5944 (4) | 0.2746 (3) | 0.8806 (3) | 0.0407 (6) | |
H6A | 0.6974 | 0.3238 | 0.8841 | 0.049* | |
H6B | 0.5071 | 0.2639 | 0.9761 | 0.049* | |
H2 | 0.729 (5) | 0.084 (3) | 0.859 (4) | 0.059 (11)* | |
H1 | 0.488 (5) | 0.331 (3) | 0.605 (3) | 0.055 (10)* |
U11 | U22 | U33 | U12 | U13 | U23 | |
Cr2 | 0.0280 (3) | 0.0257 (3) | 0.0330 (3) | 0.00169 (16) | −0.01383 (18) | −0.00392 (16) |
Cr3 | 0.0341 (3) | 0.0318 (3) | 0.0264 (3) | −0.00484 (17) | −0.01470 (18) | 0.00289 (16) |
Cr1 | 0.0396 (3) | 0.0279 (3) | 0.0419 (3) | −0.00318 (18) | −0.0270 (2) | −0.00128 (18) |
O8 | 0.0382 (10) | 0.0496 (12) | 0.0319 (10) | 0.0023 (8) | −0.0110 (8) | 0.0011 (8) |
O10 | 0.0633 (14) | 0.0465 (12) | 0.0461 (12) | −0.0121 (10) | −0.0381 (11) | 0.0048 (9) |
O9 | 0.0691 (15) | 0.0414 (12) | 0.0462 (12) | −0.0177 (11) | −0.0135 (11) | 0.0101 (9) |
O7 | 0.0379 (10) | 0.0627 (13) | 0.0324 (10) | 0.0092 (9) | −0.0172 (8) | −0.0093 (9) |
O5 | 0.0476 (12) | 0.0506 (12) | 0.0381 (11) | −0.0018 (10) | −0.0061 (9) | 0.0027 (9) |
O6 | 0.0487 (12) | 0.0316 (11) | 0.0732 (15) | 0.0076 (9) | −0.0264 (11) | −0.0098 (10) |
O4 | 0.0385 (11) | 0.0357 (10) | 0.0696 (14) | −0.0026 (8) | −0.0253 (10) | −0.0136 (10) |
O2 | 0.0427 (11) | 0.0385 (11) | 0.0698 (14) | 0.0019 (9) | −0.0304 (11) | −0.0031 (10) |
O1 | 0.0914 (19) | 0.0553 (14) | 0.0744 (17) | 0.0237 (13) | −0.0663 (16) | −0.0234 (12) |
O3 | 0.0698 (17) | 0.0544 (15) | 0.0797 (18) | −0.0210 (13) | −0.0249 (14) | 0.0210 (13) |
N1 | 0.0446 (13) | 0.0348 (12) | 0.0302 (11) | 0.0027 (10) | −0.0236 (10) | 0.0025 (9) |
N2 | 0.0304 (11) | 0.0351 (12) | 0.0337 (12) | −0.0006 (9) | −0.0150 (9) | 0.0106 (9) |
C1 | 0.0532 (18) | 0.0574 (19) | 0.0279 (14) | −0.0007 (15) | −0.0032 (13) | 0.0055 (13) |
C2 | 0.0280 (13) | 0.0492 (16) | 0.0436 (16) | 0.0005 (12) | −0.0047 (12) | 0.0037 (13) |
C3 | 0.059 (2) | 0.0399 (16) | 0.081 (2) | −0.0100 (14) | −0.0497 (19) | −0.0023 (15) |
C4 | 0.0385 (15) | 0.0292 (14) | 0.0624 (19) | −0.0104 (11) | −0.0164 (14) | 0.0085 (12) |
C5 | 0.0524 (17) | 0.0315 (13) | 0.0360 (14) | 0.0056 (12) | −0.0197 (13) | −0.0068 (11) |
C6 | 0.0510 (17) | 0.0446 (16) | 0.0307 (14) | −0.0011 (13) | −0.0204 (12) | −0.0055 (11) |
Cr2—O5 | 1.581 (2) | N2—C4 | 1.500 (4) |
Cr2—O6 | 1.594 (2) | N2—H2 | 0.836 (19) |
Cr2—O4 | 1.702 (2) | C1—C2 | 1.523 (4) |
Cr2—O7 | 1.7195 (19) | C1—H1A | 0.9700 |
Cr3—O8 | 1.5947 (19) | C1—H1B | 0.9700 |
Cr3—O9 | 1.602 (2) | C2—H2A | 0.9700 |
Cr3—O10 | 1.618 (2) | C2—H2B | 0.9700 |
Cr3—O7 | 1.817 (2) | C3—C4 | 1.521 (4) |
Cr1—O1 | 1.587 (2) | C3—H3A | 0.9700 |
Cr1—O3 | 1.601 (3) | C3—H3B | 0.9700 |
Cr1—O2 | 1.614 (2) | C4—H4A | 0.9700 |
Cr1—O4 | 1.837 (2) | C4—H4B | 0.9700 |
N1—C3 | 1.477 (4) | C5—C6 | 1.502 (4) |
N1—C5 | 1.484 (3) | C5—H5A | 0.9700 |
N1—C1 | 1.499 (4) | C5—H5B | 0.9700 |
N1—H1 | 0.862 (18) | C6—H6A | 0.9700 |
N2—C6 | 1.488 (4) | C6—H6B | 0.9700 |
N2—C2 | 1.495 (3) | ||
O5—Cr2—O6 | 108.74 (12) | C2—C1—H1A | 110.1 |
O5—Cr2—O4 | 111.28 (12) | N1—C1—H1B | 110.1 |
O6—Cr2—O4 | 109.73 (11) | C2—C1—H1B | 110.1 |
O5—Cr2—O7 | 108.80 (11) | H1A—C1—H1B | 108.4 |
O6—Cr2—O7 | 107.38 (11) | N2—C2—C1 | 107.8 (2) |
O4—Cr2—O7 | 110.80 (11) | N2—C2—H2A | 110.1 |
O8—Cr3—O9 | 110.10 (12) | C1—C2—H2A | 110.1 |
O8—Cr3—O10 | 110.28 (11) | N2—C2—H2B | 110.1 |
O9—Cr3—O10 | 111.71 (12) | C1—C2—H2B | 110.1 |
O8—Cr3—O7 | 107.76 (10) | H2A—C2—H2B | 108.5 |
O9—Cr3—O7 | 109.18 (12) | N1—C3—C4 | 109.0 (2) |
O10—Cr3—O7 | 107.69 (11) | N1—C3—H3A | 109.9 |
O1—Cr1—O3 | 110.76 (16) | C4—C3—H3A | 109.9 |
O1—Cr1—O2 | 111.56 (14) | N1—C3—H3B | 109.9 |
O3—Cr1—O2 | 110.19 (13) | C4—C3—H3B | 109.9 |
O1—Cr1—O4 | 109.14 (11) | H3A—C3—H3B | 108.3 |
O3—Cr1—O4 | 106.17 (13) | N2—C4—C3 | 107.3 (2) |
O2—Cr1—O4 | 108.85 (10) | N2—C4—H4A | 110.2 |
Cr2—O7—Cr3 | 132.80 (12) | C3—C4—H4A | 110.2 |
Cr2—O4—Cr1 | 127.34 (12) | N2—C4—H4B | 110.2 |
C3—N1—C5 | 110.2 (2) | C3—C4—H4B | 110.2 |
C3—N1—C1 | 109.8 (2) | H4A—C4—H4B | 108.5 |
C5—N1—C1 | 109.4 (2) | N1—C5—C6 | 109.1 (2) |
C3—N1—H1 | 108 (2) | N1—C5—H5A | 109.9 |
C5—N1—H1 | 110 (2) | C6—C5—H5A | 109.9 |
C1—N1—H1 | 110 (2) | N1—C5—H5B | 109.9 |
C6—N2—C2 | 110.5 (2) | C6—C5—H5B | 109.9 |
C6—N2—C4 | 109.5 (2) | H5A—C5—H5B | 108.3 |
C2—N2—C4 | 110.1 (2) | N2—C6—C5 | 108.3 (2) |
C6—N2—H2 | 114 (3) | N2—C6—H6A | 110.0 |
C2—N2—H2 | 103 (3) | C5—C6—H6A | 110.0 |
C4—N2—H2 | 109 (3) | N2—C6—H6B | 110.0 |
N1—C1—C2 | 108.2 (2) | C5—C6—H6B | 110.0 |
N1—C1—H1A | 110.1 | H6A—C6—H6B | 108.4 |
O5—Cr2—O7—Cr3 | −30.2 (2) | C6—N2—C2—C1 | −52.0 (3) |
O6—Cr2—O7—Cr3 | −147.73 (18) | C4—N2—C2—C1 | 69.1 (3) |
O4—Cr2—O7—Cr3 | 92.44 (19) | N1—C1—C2—N2 | −13.7 (3) |
O8—Cr3—O7—Cr2 | 12.7 (2) | C5—N1—C3—C4 | −51.4 (3) |
O9—Cr3—O7—Cr2 | −106.89 (19) | C1—N1—C3—C4 | 69.2 (3) |
O10—Cr3—O7—Cr2 | 131.63 (18) | C6—N2—C4—C3 | 69.0 (3) |
O5—Cr2—O4—Cr1 | 48.2 (2) | C2—N2—C4—C3 | −52.8 (3) |
O6—Cr2—O4—Cr1 | 168.56 (16) | N1—C3—C4—N2 | −13.9 (4) |
O7—Cr2—O4—Cr1 | −73.03 (18) | C3—N1—C5—C6 | 67.6 (3) |
O1—Cr1—O4—Cr2 | −119.43 (19) | C1—N1—C5—C6 | −53.2 (3) |
O3—Cr1—O4—Cr2 | 121.14 (18) | C2—N2—C6—C5 | 68.0 (3) |
O2—Cr1—O4—Cr2 | 2.5 (2) | C4—N2—C6—C5 | −53.5 (3) |
C3—N1—C1—C2 | −52.4 (3) | N1—C5—C6—N2 | −12.3 (3) |
C5—N1—C1—C2 | 68.6 (3) |
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1···O10 | 0.86 (4) | 1.90 (4) | 2.738 (4) | 164 (3) |
N2—H2···O2i | 0.84 (4) | 2.13 (3) | 2.868 (3) | 147 (3) |
N2—H2···O1ii | 0.84 (4) | 2.31 (4) | 2.893 (4) | 127 (3) |
C6—H6A···O5iii | 0.97 | 2.48 | 3.339 (4) | 147 |
C6—H6B···O8iv | 0.97 | 2.33 | 3.199 (3) | 148 |
C4—H4B···O9i | 0.97 | 2.55 | 3.348 (3) | 140 |
C4—H4B···O8i | 0.97 | 2.39 | 3.294 (4) | 154 |
C4—H4A···O2iv | 0.97 | 2.47 | 3.419 (3) | 168 |
C5—H5A···O6v | 0.97 | 2.42 | 3.135 (4) | 131 |
C5—H5A···O5iv | 0.97 | 2.37 | 3.020 (3) | 124 |
Symmetry codes: (i) −x+1, −y, −z+1; (ii) x+1, y, z+1; (iii) −x+1, −y+1, −z+1; (iv) x, y, z+1; (v) −x, −y+1, −z+1. |
Experimental details
Crystal data | |
Chemical formula | C6H14N2·Cr3O10 |
Mr | 430.19 |
Crystal system, space group | Triclinic, p1 |
Temperature (K) | 273 |
a, b, c (Å) | 7.4895 (6), 9.7648 (8), 10.1427 (8) |
α, β, γ (°) | 87.661 (1), 69.497 (1), 82.771 (1) |
V (Å3) | 689.26 (10) |
Z | 2 |
Radiation type | Mo Kα |
µ (mm−1) | 2.37 |
Crystal size (mm) | 0.59 × 0.58 × 0.52 |
Data collection | |
Diffractometer | Bruker SMART CCD area-detector diffractometer |
Absorption correction | Multi-scan (SADABS; Bruker, 2000) |
Tmin, Tmax | 0.023, 0.026 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 5021, 2459, 2336 |
Rint | 0.013 |
(sin θ/λ)max (Å−1) | 0.597 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.029, 0.085, 1.07 |
No. of reflections | 2433 |
No. of parameters | 199 |
No. of restraints | 2 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.42, −0.52 |
Computer programs: SMART (Bruker, 2000), SMART, SAINT (Bruker, 2000), SHELXTL (Bruker, 2000), SHELXTL.
Cr2—O5 | 1.581 (2) | Cr3—O10 | 1.618 (2) |
Cr2—O6 | 1.594 (2) | Cr3—O7 | 1.817 (2) |
Cr2—O4 | 1.702 (2) | Cr1—O1 | 1.587 (2) |
Cr2—O7 | 1.7195 (19) | Cr1—O3 | 1.601 (3) |
Cr3—O8 | 1.5947 (19) | Cr1—O2 | 1.614 (2) |
Cr3—O9 | 1.602 (2) | Cr1—O4 | 1.837 (2) |
O5—Cr2—O6 | 108.74 (12) | O9—Cr3—O7 | 109.18 (12) |
O5—Cr2—O4 | 111.28 (12) | O10—Cr3—O7 | 107.69 (11) |
O6—Cr2—O4 | 109.73 (11) | O1—Cr1—O3 | 110.76 (16) |
O5—Cr2—O7 | 108.80 (11) | O1—Cr1—O2 | 111.56 (14) |
O6—Cr2—O7 | 107.38 (11) | O3—Cr1—O2 | 110.19 (13) |
O4—Cr2—O7 | 110.80 (11) | O1—Cr1—O4 | 109.14 (11) |
O8—Cr3—O9 | 110.10 (12) | O3—Cr1—O4 | 106.17 (13) |
O8—Cr3—O10 | 110.28 (11) | O2—Cr1—O4 | 108.85 (10) |
O9—Cr3—O10 | 111.71 (12) | Cr2—O7—Cr3 | 132.80 (12) |
O8—Cr3—O7 | 107.76 (10) | Cr2—O4—Cr1 | 127.34 (12) |
N1—C1—C2—N2 | −13.7 (3) | N1—C5—C6—N2 | −12.3 (3) |
N1—C3—C4—N2 | −13.9 (4) |
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1···O10 | 0.86 (4) | 1.90 (4) | 2.738 (4) | 164 (3) |
N2—H2···O2i | 0.84 (4) | 2.13 (3) | 2.868 (3) | 147 (3) |
N2—H2···O1ii | 0.84 (4) | 2.31 (4) | 2.893 (4) | 127 (3) |
C6—H6A···O5iii | 0.97 | 2.48 | 3.339 (4) | 147 |
C6—H6B···O8iv | 0.97 | 2.33 | 3.199 (3) | 148 |
C4—H4B···O9i | 0.97 | 2.55 | 3.348 (3) | 140 |
C4—H4B···O8i | 0.97 | 2.39 | 3.294 (4) | 154 |
C4—H4A···O2iv | 0.97 | 2.47 | 3.419 (3) | 168 |
C5—H5A···O6v | 0.97 | 2.42 | 3.135 (4) | 131 |
C5—H5A···O5iv | 0.97 | 2.37 | 3.020 (3) | 124 |
Symmetry codes: (i) −x+1, −y, −z+1; (ii) x+1, y, z+1; (iii) −x+1, −y+1, −z+1; (iv) x, y, z+1; (v) −x, −y+1, −z+1. |
Many cases of chromates and dichromates have been deposited, as well as a few cases of trichromates, and sporadic cases of tetrachromates and polychromates (Pressprich et al., 1988). It is almost impossible to predict the real form of these chromium compounds prior to experimental investigation. We report here the synthesis and structure determination of the title salt, (I), and compare its structure is compared with that of other trichromates.
Fig. 1 shows the asymmetric unit of (I), consisting of a diazabicyclo[2.2.2]octane-1,4-diium (DABCO-diium) cation and a discrete trichromate anion that are linked by an N1—H1···O10 hydrogen bond (Table 2). The trichromate anion is composed of three CrO4 tetrahedra, joined via shared O atoms. The Cr—Ot (terminal O atom) bond lengths are shorter than the Cr—Ob (bridging O atom) bonds, the mean lengths being 1.599 (5) and 1.77 (3) Å, respectively, with a strong dispersion around these mean values. The Cr—Ot distances range from 1.581 (2) to 1.618 (2) Å, and the Cr—Ob distances range from 1.702 (2) to 1.837 (2) Å (Table 1). The O—Cr—O angles range from 106.17 (13) to 111.71 (12)°, and thus deviate from the ideal value (109.5°). The Cr—O range of the inner tetrahedron of Cr2 is comparable to that of the terminal tetrahedra. Owing to the obvious difference between the magnitude of the Cr—Ob and Cr—Ot distances, as well the great disparity between the values of the O—Cr—O angles, the coordination geometries formed by the four O atoms round the Cr atom are distorted tetrahedra. These results are in good agreement with those for Rb2Cr3O10 (Blum, 1979a), (NH4)2Cr3O10 (Blum, 1979b; Blum & Guitel, 1980), K2Cr3O10 (Blum et al., 1979), dipyrazinium trichromate (Pressprich et al., 1988), tetramethylammonium trichromate (Fossε et al., 2001) and α-Cs2Cr3O10 (Kolitsch, 2003). The title compound exhibits a wide range of Cr—O—Cr angles [127.34 (12) and 132.80 (12)°, Table 1], which is different from guanidinium trichromates [132.7 (11); Stepień & Grabowski, 1977], α-Cs2Cr3O10 [136.58 (11) and 140.30 (12)°, Kolitsch, 2003], Rb2Cr3O10 [136.0 (4) and 140.0 (4)°; Löfgren, 1974] and dipyrazinium trichromate [137.3 (1) and 137.5 (2)°; Pressprich et al., 1988].
In (I), supramolecular rings, which can be described in graph-set notation as R44(26), are formed via N1—H1···O10 and N2—H2···O2i hydrogen bonds. In addition, the rings are stablized by a number of C—H···O interactions, thus establishing a network structure.
The DABCO-diium is distorted, as indicated by the N—C—C—N torsion angles, with a mean value of 13.3 (3) Å. DABCO has been observed to be disordered across the N—N axis in several cases, such as DABCO–biphenol (1:1) (Ferguson et al., 1998), DABCO–perchloride acid (1:1) (Katrusiak, 2000) and DABCO–maleic acid (1:2) (Sun & Jin, 2002). In (I), DABCO is ordered, owing to the confinement of the C—H···O interactions.