Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536803009802/br6097sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S1600536803009802/br6097Isup2.hkl |
CCDC reference: 214777
Key indicators
- Single-crystal X-ray study
- T = 293 K
- Mean (C-C) = 0.008 Å
- R factor = 0.056
- wR factor = 0.162
- Data-to-parameter ratio = 12.5
checkCIF results
No syntax errors found ADDSYM reports no extra symmetry
QDC was prepared as reported in the literature (Balasubramanian & Prathiba, 1986). To a stirred solution of CrO3 (10 g) in water (10 ml), cooled in ice, was added quinoline (9 ml), in small portions. The solution was diluted with acetone (40 ml), cooled to 253 K and the orange solid which separated out was filtered off, washed with acetone, dried in vacuo and recrystallized from water (m.p. 433 K, yield 72%).
All H atoms were placed in geometrically idealized positions, N—H = 0.86 Å and C—H = 0.93 Å, and constrained to ride on their parent atoms with Uiso(H) = 1.2Ueq(N) and 1.2Ueq(C).
Data collection: CAD-4 EXPRESS (Enraf-Nonius, 1994); cell refinement: CAD-4 EXPRESS; data reduction: XCAD4 (Harms & Wocadlo, 1995); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: WinGX (Version 1.64.02; Farrugia, 1999) and PLATON (Spek, 2002); software used to prepare material for publication: SHELXL97 and PARST (Nardelli, 1995).
(C9H8N)2[Cr2O7] | F(000) = 968 |
Mr = 476.33 | Dx = 1.695 Mg m−3 |
Monoclinic, P21/c | Melting point: 433 K |
Hall symbol: -P 2ybc | Mo Kα radiation, λ = 0.71073 Å |
a = 12.286 (5) Å | Cell parameters from 25 reflections |
b = 9.965 (3) Å | θ = 2.0–25.0° |
c = 15.386 (5) Å | µ = 1.21 mm−1 |
β = 97.67 (3)° | T = 293 K |
V = 1866.9 (11) Å3 | Needles, orange red |
Z = 4 | 0.30 × 0.20 × 0.10 mm |
Enraf-Nonius CAD-4 diffractometer | 2210 reflections with I > 2σ(I) |
Radiation source: Enraf Nonius FR590 | Rint = 0.034 |
Graphite monochromator | θmax = 25.0°, θmin = 2.4° |
Non–profiled ω/2θ scans | h = 0→14 |
Absorption correction: ψ scan (North et al., 1968) | k = 0→11 |
Tmin = 0.713, Tmax = 0.889 | l = −18→18 |
3447 measured reflections | 2 standard reflections every 60 min |
3283 independent reflections | intensity decay: none |
Refinement on F2 | Primary atom site location: structure-invariant direct methods |
Least-squares matrix: full | Secondary atom site location: difference Fourier map |
R[F2 > 2σ(F2)] = 0.056 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.162 | H-atom parameters constrained |
S = 1.04 | w = 1/[σ2(Fo2) + (0.0975P)2 + 1.1704P] where P = (Fo2 + 2Fc2)/3 |
3283 reflections | (Δ/σ)max < 0.001 |
262 parameters | Δρmax = 1.12 e Å−3 |
0 restraints | Δρmin = −0.57 e Å−3 |
(C9H8N)2[Cr2O7] | V = 1866.9 (11) Å3 |
Mr = 476.33 | Z = 4 |
Monoclinic, P21/c | Mo Kα radiation |
a = 12.286 (5) Å | µ = 1.21 mm−1 |
b = 9.965 (3) Å | T = 293 K |
c = 15.386 (5) Å | 0.30 × 0.20 × 0.10 mm |
β = 97.67 (3)° |
Enraf-Nonius CAD-4 diffractometer | 2210 reflections with I > 2σ(I) |
Absorption correction: ψ scan (North et al., 1968) | Rint = 0.034 |
Tmin = 0.713, Tmax = 0.889 | 2 standard reflections every 60 min |
3447 measured reflections | intensity decay: none |
3283 independent reflections |
R[F2 > 2σ(F2)] = 0.056 | 0 restraints |
wR(F2) = 0.162 | H-atom parameters constrained |
S = 1.04 | Δρmax = 1.12 e Å−3 |
3283 reflections | Δρmin = −0.57 e Å−3 |
262 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 | ||
N1 | 0.3239 (4) | 0.1135 (4) | 0.0009 (3) | 0.0541 (11) | |
H1 | 0.3304 | 0.0276 | 0.0019 | 0.065* | |
C11 | 0.4057 (5) | 0.1868 (7) | −0.0208 (4) | 0.0615 (15) | |
H11 | 0.4691 | 0.1452 | −0.0344 | 0.074* | |
C12 | 0.3977 (5) | 0.3259 (7) | −0.0233 (4) | 0.0624 (16) | |
H12 | 0.4551 | 0.3771 | −0.0393 | 0.075* | |
C13 | 0.3068 (4) | 0.3862 (5) | −0.0025 (3) | 0.0464 (12) | |
H13 | 0.3023 | 0.4794 | −0.0037 | 0.056* | |
C14 | 0.1210 (5) | 0.3689 (6) | 0.0417 (3) | 0.0598 (15) | |
H14 | 0.1125 | 0.4617 | 0.0412 | 0.072* | |
C15 | 0.0391 (5) | 0.2890 (7) | 0.0627 (4) | 0.0696 (19) | |
H15 | −0.0259 | 0.3274 | 0.0756 | 0.084* | |
C16 | 0.0510 (5) | 0.1492 (7) | 0.0650 (4) | 0.0622 (15) | |
H16 | −0.0058 | 0.0962 | 0.0804 | 0.075* | |
C17 | 0.1425 (4) | 0.0910 (6) | 0.0457 (3) | 0.0535 (13) | |
H17 | 0.1494 | −0.0019 | 0.0479 | 0.064* | |
C18 | 0.2283 (4) | 0.1701 (5) | 0.0219 (3) | 0.0392 (11) | |
C19 | 0.2195 (4) | 0.3115 (5) | 0.0206 (3) | 0.0415 (11) | |
N2 | 0.3078 (3) | 0.0656 (4) | 0.2508 (2) | 0.0389 (9) | |
H2 | 0.3085 | −0.0207 | 0.2510 | 0.047* | |
C21 | 0.3936 (4) | 0.1291 (5) | 0.2287 (3) | 0.0460 (12) | |
H21 | 0.4531 | 0.0806 | 0.2138 | 0.055* | |
C22 | 0.3959 (5) | 0.2692 (5) | 0.2273 (4) | 0.0514 (13) | |
H22 | 0.4563 | 0.3145 | 0.2112 | 0.062* | |
C23 | 0.3088 (4) | 0.3379 (5) | 0.2499 (3) | 0.0477 (12) | |
H23 | 0.3098 | 0.4313 | 0.2491 | 0.057* | |
C24 | 0.1227 (5) | 0.3363 (5) | 0.2985 (3) | 0.0545 (14) | |
H24 | 0.1205 | 0.4295 | 0.3004 | 0.065* | |
C25 | 0.0368 (5) | 0.2649 (6) | 0.3188 (4) | 0.0586 (15) | |
H25 | −0.0242 | 0.3094 | 0.3346 | 0.070* | |
C26 | 0.0379 (4) | 0.1243 (6) | 0.3163 (3) | 0.0536 (13) | |
H26 | −0.0230 | 0.0765 | 0.3293 | 0.064* | |
C27 | 0.1267 (4) | 0.0572 (5) | 0.2951 (3) | 0.0465 (12) | |
H27 | 0.1276 | −0.0361 | 0.2948 | 0.056* | |
C28 | 0.2174 (4) | 0.1298 (4) | 0.2737 (3) | 0.0350 (10) | |
C29 | 0.2170 (4) | 0.2711 (4) | 0.2743 (3) | 0.0375 (10) | |
Cr1 | 0.30506 (7) | 0.72205 (7) | 0.35440 (5) | 0.0406 (3) | |
Cr2 | 0.31064 (6) | 0.73438 (7) | 0.13915 (5) | 0.0366 (3) | |
O1 | 0.1883 (4) | 0.6592 (6) | 0.3580 (4) | 0.1080 (19) | |
O2 | 0.3967 (3) | 0.6074 (4) | 0.3724 (3) | 0.0643 (11) | |
O3 | 0.3303 (5) | 0.8429 (4) | 0.4207 (3) | 0.1047 (19) | |
O4 | 0.1906 (3) | 0.6964 (6) | 0.0967 (3) | 0.0929 (16) | |
O5 | 0.3916 (3) | 0.6083 (3) | 0.1416 (2) | 0.0589 (10) | |
O6 | 0.3569 (3) | 0.8591 (3) | 0.0879 (2) | 0.0614 (11) | |
O7 | 0.3085 (3) | 0.7971 (3) | 0.2489 (2) | 0.0607 (11) |
U11 | U22 | U33 | U12 | U13 | U23 | |
N1 | 0.061 (3) | 0.049 (2) | 0.051 (3) | 0.014 (2) | 0.003 (2) | 0.000 (2) |
C11 | 0.046 (3) | 0.098 (5) | 0.041 (3) | 0.011 (3) | 0.007 (3) | −0.005 (3) |
C12 | 0.058 (4) | 0.091 (5) | 0.036 (3) | −0.026 (3) | 0.002 (3) | 0.009 (3) |
C13 | 0.066 (4) | 0.041 (3) | 0.029 (3) | −0.009 (2) | −0.002 (2) | 0.0022 (19) |
C14 | 0.074 (4) | 0.063 (3) | 0.041 (3) | 0.027 (3) | 0.001 (3) | −0.012 (3) |
C15 | 0.048 (3) | 0.121 (6) | 0.041 (3) | 0.021 (4) | 0.009 (3) | −0.012 (3) |
C16 | 0.054 (4) | 0.090 (5) | 0.043 (3) | −0.011 (3) | 0.009 (3) | 0.000 (3) |
C17 | 0.058 (3) | 0.057 (3) | 0.044 (3) | −0.006 (3) | 0.001 (3) | 0.003 (2) |
C18 | 0.047 (3) | 0.047 (3) | 0.023 (2) | 0.001 (2) | 0.001 (2) | −0.0022 (19) |
C19 | 0.055 (3) | 0.042 (2) | 0.025 (2) | 0.005 (2) | −0.002 (2) | −0.002 (2) |
N2 | 0.052 (2) | 0.0322 (19) | 0.033 (2) | 0.0054 (18) | 0.0047 (18) | −0.0024 (15) |
C21 | 0.045 (3) | 0.055 (3) | 0.038 (3) | 0.004 (2) | 0.005 (2) | −0.003 (2) |
C22 | 0.049 (3) | 0.060 (3) | 0.046 (3) | −0.017 (3) | 0.010 (2) | 0.001 (2) |
C23 | 0.070 (4) | 0.032 (2) | 0.039 (3) | −0.009 (2) | 0.001 (2) | −0.0002 (19) |
C24 | 0.076 (4) | 0.044 (3) | 0.043 (3) | 0.016 (3) | 0.005 (3) | −0.003 (2) |
C25 | 0.053 (3) | 0.081 (4) | 0.044 (3) | 0.017 (3) | 0.014 (3) | 0.002 (3) |
C26 | 0.047 (3) | 0.077 (4) | 0.037 (3) | −0.002 (3) | 0.009 (2) | 0.010 (3) |
C27 | 0.053 (3) | 0.045 (3) | 0.041 (3) | −0.009 (2) | 0.005 (2) | 0.005 (2) |
C28 | 0.045 (3) | 0.039 (2) | 0.021 (2) | 0.0022 (19) | 0.0021 (19) | −0.0004 (17) |
C29 | 0.048 (3) | 0.038 (2) | 0.024 (2) | 0.001 (2) | −0.0012 (19) | −0.0030 (18) |
Cr1 | 0.0604 (6) | 0.0343 (4) | 0.0298 (4) | 0.0023 (3) | 0.0166 (4) | 0.0007 (3) |
Cr2 | 0.0472 (5) | 0.0370 (4) | 0.0269 (4) | −0.0002 (3) | 0.0089 (3) | −0.0026 (3) |
O1 | 0.068 (3) | 0.117 (4) | 0.146 (5) | −0.004 (3) | 0.043 (3) | 0.022 (4) |
O2 | 0.078 (3) | 0.058 (2) | 0.059 (3) | 0.0172 (19) | 0.012 (2) | 0.0113 (19) |
O3 | 0.227 (6) | 0.046 (2) | 0.038 (2) | 0.013 (3) | 0.009 (3) | −0.0123 (18) |
O4 | 0.056 (3) | 0.138 (4) | 0.087 (4) | −0.022 (3) | 0.015 (2) | −0.021 (3) |
O5 | 0.091 (3) | 0.0390 (18) | 0.049 (2) | 0.0136 (18) | 0.016 (2) | −0.0014 (16) |
O6 | 0.096 (3) | 0.0411 (18) | 0.052 (2) | 0.0033 (19) | 0.028 (2) | 0.0077 (16) |
O7 | 0.113 (3) | 0.0398 (19) | 0.032 (2) | 0.0141 (19) | 0.022 (2) | 0.0001 (14) |
N1—C11 | 1.321 (7) | C22—C23 | 1.355 (7) |
N1—C18 | 1.380 (6) | C22—H22 | 0.9300 |
N1—H1 | 0.8600 | C23—C29 | 1.403 (7) |
C11—C12 | 1.389 (9) | C23—H23 | 0.9300 |
C11—H11 | 0.9300 | C24—C25 | 1.343 (8) |
C12—C13 | 1.344 (8) | C24—C29 | 1.421 (7) |
C12—H12 | 0.9300 | C24—H24 | 0.9300 |
C13—C19 | 1.391 (7) | C25—C26 | 1.402 (8) |
C13—H13 | 0.9300 | C25—H25 | 0.9300 |
C14—C15 | 1.356 (8) | C26—C27 | 1.356 (7) |
C14—C19 | 1.415 (7) | C26—H26 | 0.9300 |
C14—H14 | 0.9300 | C27—C28 | 1.404 (6) |
C15—C16 | 1.401 (9) | C27—H27 | 0.9300 |
C15—H15 | 0.9300 | C28—C29 | 1.408 (6) |
C16—C17 | 1.333 (8) | Cr1—O1 | 1.572 (5) |
C16—H16 | 0.9300 | Cr1—O3 | 1.582 (4) |
C17—C18 | 1.404 (7) | Cr1—O2 | 1.602 (4) |
C17—H17 | 0.9300 | Cr1—O7 | 1.793 (3) |
C18—C19 | 1.414 (7) | Cr2—O4 | 1.577 (4) |
N2—C21 | 1.312 (6) | Cr2—O5 | 1.599 (3) |
N2—C28 | 1.368 (6) | Cr2—O6 | 1.615 (3) |
N2—H2 | 0.8600 | Cr2—O7 | 1.804 (3) |
C21—C22 | 1.397 (7) | Cg1—Cg4 | 3.667 (3) |
C21—H21 | 0.9300 | Cg2—Cg3 | 3.609 (3) |
C11—N1—C18 | 122.2 (5) | C23—C22—H22 | 120.6 |
C11—N1—H1 | 118.9 | C21—C22—H22 | 120.6 |
C18—N1—H1 | 118.9 | C22—C23—C29 | 121.3 (4) |
N1—C11—C12 | 120.4 (5) | C22—C23—H23 | 119.4 |
N1—C11—H11 | 119.8 | C29—C23—H23 | 119.4 |
C12—C11—H11 | 119.8 | C25—C24—C29 | 120.9 (5) |
C13—C12—C11 | 119.8 (5) | C25—C24—H24 | 119.6 |
C13—C12—H12 | 120.1 | C29—C24—H24 | 119.6 |
C11—C12—H12 | 120.1 | C24—C25—C26 | 120.8 (5) |
C12—C13—C19 | 121.0 (5) | C24—C25—H25 | 119.6 |
C12—C13—H13 | 119.5 | C26—C25—H25 | 119.6 |
C19—C13—H13 | 119.5 | C27—C26—C25 | 120.7 (5) |
C15—C14—C19 | 120.1 (5) | C27—C26—H26 | 119.7 |
C15—C14—H14 | 119.9 | C25—C26—H26 | 119.7 |
C19—C14—H14 | 119.9 | C26—C27—C28 | 119.5 (5) |
C14—C15—C16 | 120.8 (5) | C26—C27—H27 | 120.3 |
C14—C15—H15 | 119.6 | C28—C27—H27 | 120.3 |
C16—C15—H15 | 119.6 | N2—C28—C27 | 121.1 (4) |
C17—C16—C15 | 121.0 (6) | N2—C28—C29 | 118.2 (4) |
C17—C16—H16 | 119.5 | C27—C28—C29 | 120.7 (4) |
C15—C16—H16 | 119.5 | C23—C29—C28 | 118.0 (4) |
C16—C17—C18 | 119.9 (5) | C23—C29—C24 | 124.5 (5) |
C16—C17—H17 | 120.0 | C28—C29—C24 | 117.5 (4) |
C18—C17—H17 | 120.0 | O1—Cr1—O3 | 112.4 (3) |
N1—C18—C17 | 121.6 (4) | O1—Cr1—O2 | 109.5 (3) |
N1—C18—C19 | 118.1 (4) | O3—Cr1—O2 | 111.0 (3) |
C17—C18—C19 | 120.3 (5) | O1—Cr1—O7 | 109.2 (3) |
C13—C19—C18 | 118.5 (5) | O3—Cr1—O7 | 103.9 (2) |
C13—C19—C14 | 123.7 (5) | O2—Cr1—O7 | 110.62 (18) |
C18—C19—C14 | 117.8 (5) | O4—Cr2—O5 | 111.4 (3) |
C21—N2—C28 | 123.3 (4) | O4—Cr2—O6 | 110.7 (3) |
C21—N2—H2 | 118.4 | O5—Cr2—O6 | 110.95 (19) |
C28—N2—H2 | 118.4 | O4—Cr2—O7 | 110.0 (2) |
N2—C21—C22 | 120.3 (5) | O5—Cr2—O7 | 109.66 (18) |
N2—C21—H21 | 119.8 | O6—Cr2—O7 | 103.92 (17) |
C22—C21—H21 | 119.8 | Cr1—O7—Cr2 | 135.1 (2) |
C23—C22—C21 | 118.9 (5) | ||
C18—N1—C11—C12 | −0.2 (8) | C29—C24—C25—C26 | −0.1 (8) |
N1—C11—C12—C13 | 0.9 (9) | C24—C25—C26—C27 | 1.4 (9) |
C11—C12—C13—C19 | −0.8 (8) | C25—C26—C27—C28 | −1.4 (8) |
C19—C14—C15—C16 | 1.0 (8) | C21—N2—C28—C27 | 178.6 (4) |
C14—C15—C16—C17 | −0.9 (9) | C21—N2—C28—C29 | −0.7 (6) |
C15—C16—C17—C18 | −0.4 (9) | C26—C27—C28—N2 | −179.1 (4) |
C11—N1—C18—C17 | −179.3 (5) | C26—C27—C28—C29 | 0.2 (7) |
C11—N1—C18—C19 | −0.5 (7) | C22—C23—C29—C28 | −0.8 (7) |
C16—C17—C18—N1 | −179.6 (5) | C22—C23—C29—C24 | −179.9 (5) |
C16—C17—C18—C19 | 1.7 (8) | N2—C28—C29—C23 | 1.1 (6) |
C12—C13—C19—C18 | 0.1 (7) | C27—C28—C29—C23 | −178.2 (4) |
C12—C13—C19—C14 | −178.9 (5) | N2—C28—C29—C24 | −179.7 (4) |
N1—C18—C19—C13 | 0.6 (7) | C27—C28—C29—C24 | 1.0 (7) |
C17—C18—C19—C13 | 179.4 (4) | C25—C24—C29—C23 | 178.1 (5) |
N1—C18—C19—C14 | 179.6 (4) | C25—C24—C29—C28 | −1.0 (7) |
C17—C18—C19—C14 | −1.6 (7) | O1—Cr1—O7—Cr2 | −71.5 (4) |
C15—C14—C19—C13 | 179.3 (5) | O3—Cr1—O7—Cr2 | 168.3 (4) |
C15—C14—C19—C18 | 0.3 (7) | O2—Cr1—O7—Cr2 | 49.1 (4) |
C28—N2—C21—C22 | −0.1 (7) | O4—Cr2—O7—Cr1 | 81.3 (4) |
N2—C21—C22—C23 | 0.5 (8) | O5—Cr2—O7—Cr1 | −41.6 (4) |
C21—C22—C23—C29 | 0.0 (8) | O6—Cr2—O7—Cr1 | −160.3 (3) |
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1···O6i | 0.86 | 2.14 | 2.871 (5) | 143 |
N2—H2···O7i | 0.86 | 1.82 | 2.676 (5) | 179 |
C11—H11···O6ii | 0.93 | 2.39 | 3.254 (7) | 154 |
C13—H13···O3iii | 0.93 | 2.17 | 2.976 (6) | 144 |
C21—H21···O2iv | 0.93 | 2.43 | 3.189 (6) | 139 |
C24—H24···O1 | 0.93 | 2.55 | 3.413 (8) | 154 |
Symmetry codes: (i) x, y−1, z; (ii) −x+1, −y+1, −z; (iii) x, −y+3/2, z−1/2; (iv) −x+1, y−1/2, −z+1/2. |
Experimental details
Crystal data | |
Chemical formula | (C9H8N)2[Cr2O7] |
Mr | 476.33 |
Crystal system, space group | Monoclinic, P21/c |
Temperature (K) | 293 |
a, b, c (Å) | 12.286 (5), 9.965 (3), 15.386 (5) |
β (°) | 97.67 (3) |
V (Å3) | 1866.9 (11) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 1.21 |
Crystal size (mm) | 0.30 × 0.20 × 0.10 |
Data collection | |
Diffractometer | Enraf-Nonius CAD-4 diffractometer |
Absorption correction | ψ scan (North et al., 1968) |
Tmin, Tmax | 0.713, 0.889 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 3447, 3283, 2210 |
Rint | 0.034 |
(sin θ/λ)max (Å−1) | 0.594 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.056, 0.162, 1.04 |
No. of reflections | 3283 |
No. of parameters | 262 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 1.12, −0.57 |
Computer programs: CAD-4 EXPRESS (Enraf-Nonius, 1994), CAD-4 EXPRESS, XCAD4 (Harms & Wocadlo, 1995), SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), WinGX (Version 1.64.02; Farrugia, 1999) and PLATON (Spek, 2002), SHELXL97 and PARST (Nardelli, 1995).
Cg1—Cg4 | 3.667 (3) | Cg2—Cg3 | 3.609 (3) |
O1—Cr1—O7—Cr2 | −71.5 (4) | O6—Cr2—O7—Cr1 | −160.3 (3) |
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1···O6i | 0.86 | 2.14 | 2.871 (5) | 143 |
N2—H2···O7i | 0.86 | 1.82 | 2.676 (5) | 179 |
C11—H11···O6ii | 0.93 | 2.39 | 3.254 (7) | 154 |
C13—H13···O3iii | 0.93 | 2.17 | 2.976 (6) | 144 |
C21—H21···O2iv | 0.93 | 2.43 | 3.189 (6) | 139 |
C24—H24···O1 | 0.93 | 2.55 | 3.413 (8) | 154 |
Symmetry codes: (i) x, y−1, z; (ii) −x+1, −y+1, −z; (iii) x, −y+3/2, z−1/2; (iv) −x+1, y−1/2, −z+1/2. |
Subscribe to Acta Crystallographica Section E: Crystallographic Communications
The full text of this article is available to subscribers to the journal.
- Information on subscribing
- Sample issue
- If you have already subscribed, you may need to register
The X-ray study of quinolinium dichromate (QDC), (I), was undertaken in order to study the hydrogen-bond patterns and crystal packing. QDC is reported to be a selective oxidant for a wide range of substrates in view of its ease of preparation and high stability (Aruna et al., 1994; Aruna & Manikyamba, 1995; Balasubramanian & Prathiba, 1986; Karim & Mahanti, 1992; Kharnaior et al., 2001; Lyngdoh et al., 2001; Ravishankar et al., 1998).
In QDC, two heterocyclic quinolinium cation moieties and a dichromate anion moiety are connected through N—H···O and C—H···O intermolecular hydrogen bonds. The refined asymmetric unit and the numbering scheme are shown in Fig. 1. The aromatic quinolinium moieties form π–π-stacking interactions. One of the six-membered rings, Cg1 (defined by atoms N1, C11–C13, C18 and C19), of the quinolinium moiety at (x, y, z) has a π–π interaction with one of the six-membered rings, Cg4 (defined by atoms C24–C29), at (x, 1/2 − y,-1/2 + z) of another quinolinium moiety. The other six-membered ring, Cg3 (defined by atoms C14–C19), has a π–π contact with Cg2 (defined by atoms N2, C21–C23, C28 and C29) of the quinolinium moiety which belongs to the same asymmetric unit as that of residue (I). The distances between the ring centroids, Cg, are listed in Table 1. The quinolinium rings are stacked along the the c axis, having their planes nearly parallel to the (001) plane (Fig. 2), as is evident from the fact that the dihedral angle between their least-squares planes is 2.87 (9)°. The corresponding bond lengths of the two quinolinium rings are in very good agreement. The largest difference in bond length is observed in the bonds C16—C17 [1.333 (8) Å] and C26—C27 [1.356 (7) Å]. The agreement is also good for the corresponding core angles between the rings, with maximum difference existing between C11—N1—C18 [122.2 (5)°] and C21—N2—C28 [123.3 (4)°]. However, these differences are not significant, as they are well within the 3σ level. Also, the bond distances and angles of the molecule are reasonably comparable with compounds containing the similar quinazoline ring and are in agreement with the related structures (Dobson & Gerkin, 1999a,b; Rajnikant et al., 2002).
The dichromate ion consits of two CrO4 tetrahedra sharing one O atom (the bridge atom O7). The CrO4 groups are slightly distorted tetrahedra. The distances of the chromium atoms from the bridging oxygen, O7, are 1.793 (3) (Cr1—O7) and 1.804 (3) Å (Cr2—O7). The other Cr—O distances range from 1.572 (5) (Cr1—O1) to 1.615 (3) Å (Cr2—O6). The dichromate geometry is normal for Cr1—O7—Cr2 [135.1 (2)°]. The angles O3—Cr1—O7 [103.9 (2)°] and O6—Cr2—O7 [103.92 (17)°] significantly differ from the tetrahedral geometry, 109.5°. The similar deviation is described for analogous sulfates in the paper by Brown (1973), where two types of angular distortions occur, known as the bond-length effect and the configurational effect. In the present case, the bond -ength effect is not observed since the O atoms are not in contact, but the configurational effect is observed. There is no significant deviation in the bond angles and distances of the dichromate moiety from the values of similar structures reported in the literature (Panagiotopoulos & Brown, 1972; Dahan, 1975; Blum et al., 1980).
The details of the N—H···O (Fig. 3) and C—H···O (Fig. 4) interactions observed are presented in Table 2. As seen from Table 2, for (I), atoms N1 and N2 act as hydrogen-bond donors and form N—H···O intermolecular interactions with atoms O6 and O7 of the adjacent molecule. H11 on C11 is involved in a weak intermolecular C—H···O interaction with the terminal atom O6 of the adjacent dichromate moiety and H13 on C13 is involved in a weak intermolecular C—H···O interaction with another terminal atom, O3, of another molecule. These interactions produce a continuous chain, which runs parallel to the c axis. Atom C21 forms a weak C—H···O intermolecular interaction with O2 of a neighbouring centrosymmetrically related molecule. Apart from the intermolecular hydrogen bonds, the structure is also stabilized by π–π-stacking interactions (Table 1).