Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270105001605/gg1225sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S0108270105001605/gg1225Isup2.hkl | |
Structure factor file (CIF format) https://doi.org/10.1107/S0108270105001605/gg1225IIsup3.hkl |
CCDC references: 269006; 269007
Single crystals of Ni(4,4'–bipyridyl)2Cr2O7 were synthesized by placing NiO (44.1 mg, Aldrich, 99.99%), (NH4)2Cr2O7 (291.6 mg, Aldrich, 99.5+%) and 4,4'–bipyridine (453.2 mg, Aldrich, 98%) into a Teflon (fluoroethylenepropylene) pouch (Harrison et al., 1993). To the pouch were added aqueous HF (885.9 mg, Aldrich, 49%, w/v) and deionized H2O (55.1 mg). The pouches were heat sealed and placed in a 125 ml autoclave, which was back-filled with H2O (45 ml). The autoclave was heated in a convection oven for 24 h at 423 K and cooled to room temperature at 6 K h−1. The pouch was opened in air and (I) was recovered by filtration in a 39% yield based on Ni content. Single crystals of Cu(4,4'–dipyridyl)2Cr2O7 were synthesized in a similar manner using Cu2O (44.6 mg, Aldrich, 97%), (pyH)2Cr2O7 (234.5 mg, Fluka, 98.0%), 4,4'–bipyridine (195.1 mg, Aldrich, 98%), aqueous HF (112.3 mg, Aldrich, 49%wv) and deionized H2O (1111.5 mg). Compound (II) was recovered by filtration in a 75% yield based on Cu content. Crystals of (I) and (II) are isomorphous.
H atoms were included in the final refinement model as riding atoms in idealized positions using the default SHELXL settings at low temperature [C—H = 0.95 \%A and Uiso(H) = 1.2Ueq(C) or 1.5Ueq(C)].
For both compounds, data collection: SMART-NT (Siemens, 1996); cell refinement: SAINT-Plus (Siemens, 1996); data reduction: SAINT-Plus; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ATOMS (Dowty, 1999); software used to prepare material for publication: program (reference)?.
[Ni(C10H8N2)2(Cr2O7)] | F(000) = 2368 |
Mr = 587.08 | Dx = 1.802 Mg m−3 Dm = 1.784 (3) Mg m−3 Dm measured by flotation pycnometry |
Monoclinic, C_1_2/c_1 | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -C 2yc | Cell parameters from 5184 reflections |
a = 21.343 (7) Å | θ = 4–28° |
b = 15.260 (5) Å | µ = 1.90 mm−1 |
c = 16.658 (6) Å | T = 153 K |
β = 127.094 (5)° | Columnar, blue |
V = 4328 (3) Å3 | 0.21 × 0.16 × 0.15 mm |
Z = 8 |
Bruker SMART AXS diffractometer | 5184 independent reflections |
Radiation source: fine-focus sealed tube | 4364 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.083 |
ω–2θ scans | θmax = 28.3°, θmin = 1.8° |
Absorption correction: analytical face-indexed (reference?) | h = −28→28 |
Tmin = 0.718, Tmax = 0.874 | k = −20→20 |
19357 measured reflections | l = −21→22 |
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)] = 0.038 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.099 | H-atom parameters constrained |
S = 1.08 | w = 1/[σ2(Fo2) + (0.0448P)2 + 7.5127P] where P = (Fo2 + 2Fc2)/3 |
5184 reflections | (Δ/σ)max = 0.001 |
307 parameters | Δρmax = 1.19 e Å−3 |
0 restraints | Δρmin = −0.64 e Å−3 |
[Ni(C10H8N2)2(Cr2O7)] | V = 4328 (3) Å3 |
Mr = 587.08 | Z = 8 |
Monoclinic, C_1_2/c_1 | Mo Kα radiation |
a = 21.343 (7) Å | µ = 1.90 mm−1 |
b = 15.260 (5) Å | T = 153 K |
c = 16.658 (6) Å | 0.21 × 0.16 × 0.15 mm |
β = 127.094 (5)° |
Bruker SMART AXS diffractometer | 5184 independent reflections |
Absorption correction: analytical face-indexed (reference?) | 4364 reflections with I > 2σ(I) |
Tmin = 0.718, Tmax = 0.874 | Rint = 0.083 |
19357 measured reflections |
R[F2 > 2σ(F2)] = 0.038 | 0 restraints |
wR(F2) = 0.099 | H-atom parameters constrained |
S = 1.08 | Δρmax = 1.19 e Å−3 |
5184 reflections | Δρmin = −0.64 e Å−3 |
307 parameters |
Experimental. Stationary background counts were recorded at each end of the scan, and the scan time:background time ratio was 2:1. |
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. |
x | y | z | Uiso*/Ueq | ||
Ni | 0.133935 (17) | 0.251246 (17) | 0.62064 (2) | 0.01183 (9) | |
Cr1 | 0.33243 (2) | 0.20390 (3) | 0.77624 (3) | 0.01774 (11) | |
Cr2 | 0.42678 (2) | 0.26482 (3) | 1.00533 (3) | 0.01608 (10) | |
O1 | 0.25321 (10) | 0.26572 (11) | 0.70270 (13) | 0.0187 (3) | |
O2 | 0.31487 (11) | 0.10568 (13) | 0.73330 (15) | 0.0313 (4) | |
O3 | 0.40446 (11) | 0.24397 (13) | 0.78138 (15) | 0.0281 (4) | |
O4 | 0.35578 (10) | 0.19958 (12) | 0.89870 (12) | 0.0219 (4) | |
O5 | 0.40137 (12) | 0.36647 (12) | 0.98216 (16) | 0.0315 (4) | |
O6 | 0.42760 (11) | 0.23169 (13) | 1.09782 (14) | 0.0273 (4) | |
O7 | 0.51402 (10) | 0.25213 (10) | 1.03205 (13) | 0.0175 (3) | |
N1 | 0.12171 (11) | 0.35891 (13) | 0.52794 (14) | 0.0150 (4) | |
N2 | 0.13155 (11) | 0.16338 (13) | 0.52288 (14) | 0.0146 (4) | |
N3 | 0.13357 (11) | −0.14412 (13) | 0.20560 (14) | 0.0156 (4) | |
N4 | 0.13908 (11) | 0.65958 (12) | 0.21796 (14) | 0.0140 (4) | |
C1 | 0.15302 (14) | 0.43888 (15) | 0.56355 (17) | 0.0170 (4) | |
H1 | 0.1735 | 0.4526 | 0.6309 | 0.020* | |
C2 | 0.15693 (14) | 0.50248 (15) | 0.50702 (17) | 0.0168 (4) | |
H2 | 0.1775 | 0.5590 | 0.5344 | 0.020* | |
C3 | 0.13002 (13) | 0.48201 (15) | 0.40908 (17) | 0.0153 (4) | |
C4 | 0.09568 (13) | 0.39992 (15) | 0.37108 (17) | 0.0162 (4) | |
H4 | 0.0762 | 0.3837 | 0.3047 | 0.019* | |
C5 | 0.09025 (13) | 0.34223 (15) | 0.43078 (17) | 0.0159 (4) | |
H5 | 0.0632 | 0.2885 | 0.4021 | 0.019* | |
C6 | 0.07940 (13) | 0.60332 (14) | 0.18138 (17) | 0.0150 (4) | |
H6 | 0.0379 | 0.6037 | 0.1112 | 0.018* | |
C7 | 0.07586 (13) | 0.54488 (15) | 0.24163 (17) | 0.0161 (4) | |
H7 | 0.0331 | 0.5051 | 0.2126 | 0.019* | |
C8 | 0.13481 (14) | 0.54408 (15) | 0.34481 (17) | 0.0157 (4) | |
C9 | 0.19738 (14) | 0.60186 (15) | 0.38292 (17) | 0.0177 (5) | |
H9 | 0.2393 | 0.6030 | 0.4529 | 0.021* | |
C10 | 0.19774 (14) | 0.65782 (15) | 0.31730 (17) | 0.0177 (5) | |
H10 | 0.2411 | 0.6963 | 0.3437 | 0.021* | |
C11 | 0.18492 (13) | 0.16913 (15) | 0.50452 (17) | 0.0159 (4) | |
H11 | 0.2261 | 0.2108 | 0.5412 | 0.019* | |
C12 | 0.18243 (14) | 0.11706 (15) | 0.43466 (17) | 0.0171 (4) | |
H12 | 0.2194 | 0.1255 | 0.4211 | 0.021* | |
C13 | 0.12506 (14) | 0.05208 (15) | 0.38428 (17) | 0.0158 (4) | |
C14 | 0.06953 (14) | 0.04724 (15) | 0.40277 (17) | 0.0174 (5) | |
H14 | 0.0287 | 0.0049 | 0.3687 | 0.021* | |
C15 | 0.07394 (14) | 0.10401 (15) | 0.47052 (17) | 0.0166 (4) | |
H15 | 0.0346 | 0.1009 | 0.4805 | 0.020* | |
C16 | 0.10397 (14) | −0.16031 (15) | 0.25672 (17) | 0.0175 (5) | |
H16 | 0.0842 | −0.2173 | 0.2524 | 0.021* | |
C17 | 0.10103 (14) | −0.09849 (16) | 0.31476 (18) | 0.0182 (5) | |
H17 | 0.0821 | −0.1140 | 0.3518 | 0.022* | |
C18 | 0.12610 (13) | −0.01273 (15) | 0.31878 (16) | 0.0158 (4) | |
C19 | 0.15314 (14) | 0.00602 (16) | 0.26246 (17) | 0.0180 (5) | |
H19 | 0.1686 | 0.0639 | 0.2604 | 0.022* | |
C20 | 0.15720 (14) | −0.06155 (15) | 0.20910 (17) | 0.0170 (4) | |
H20 | 0.1778 | −0.0485 | 0.1734 | 0.020* |
U11 | U22 | U33 | U12 | U13 | U23 | |
Ni | 0.01557 (15) | 0.01088 (15) | 0.01136 (15) | 0.00057 (10) | 0.00934 (12) | 0.00010 (10) |
Cr1 | 0.01608 (19) | 0.0201 (2) | 0.01673 (19) | 0.00120 (14) | 0.00972 (16) | −0.00295 (15) |
Cr2 | 0.01665 (19) | 0.0174 (2) | 0.01540 (19) | 0.00174 (14) | 0.01030 (16) | 0.00025 (14) |
O1 | 0.0188 (8) | 0.0199 (8) | 0.0168 (8) | 0.0029 (7) | 0.0105 (7) | −0.0008 (7) |
O2 | 0.0307 (10) | 0.0247 (10) | 0.0315 (10) | 0.0039 (8) | 0.0151 (9) | −0.0086 (8) |
O3 | 0.0203 (9) | 0.0400 (12) | 0.0267 (10) | 0.0000 (8) | 0.0156 (8) | −0.0007 (8) |
O4 | 0.0204 (8) | 0.0261 (9) | 0.0165 (8) | −0.0027 (7) | 0.0096 (7) | 0.0002 (7) |
O5 | 0.0362 (11) | 0.0184 (9) | 0.0390 (11) | 0.0082 (8) | 0.0222 (9) | 0.0017 (8) |
O6 | 0.0304 (10) | 0.0353 (11) | 0.0227 (9) | 0.0005 (8) | 0.0194 (8) | 0.0009 (8) |
O7 | 0.0174 (8) | 0.0192 (8) | 0.0171 (8) | −0.0008 (6) | 0.0111 (7) | −0.0010 (6) |
N1 | 0.0166 (9) | 0.0145 (9) | 0.0156 (9) | 0.0014 (7) | 0.0106 (8) | 0.0034 (7) |
N2 | 0.0190 (9) | 0.0128 (9) | 0.0134 (9) | 0.0013 (7) | 0.0104 (8) | 0.0006 (7) |
N3 | 0.0195 (9) | 0.0157 (9) | 0.0160 (9) | −0.0017 (7) | 0.0130 (8) | −0.0023 (7) |
N4 | 0.0185 (9) | 0.0130 (9) | 0.0153 (9) | 0.0008 (7) | 0.0126 (8) | 0.0016 (7) |
C1 | 0.0203 (11) | 0.0162 (11) | 0.0163 (10) | −0.0008 (9) | 0.0120 (9) | −0.0001 (9) |
C2 | 0.0195 (11) | 0.0131 (10) | 0.0191 (11) | −0.0011 (8) | 0.0123 (9) | −0.0001 (9) |
C3 | 0.0156 (10) | 0.0143 (10) | 0.0180 (11) | 0.0028 (8) | 0.0111 (9) | 0.0044 (8) |
C4 | 0.0187 (11) | 0.0152 (11) | 0.0149 (10) | 0.0012 (9) | 0.0104 (9) | 0.0004 (8) |
C5 | 0.0180 (11) | 0.0115 (10) | 0.0163 (10) | 0.0008 (8) | 0.0094 (9) | 0.0011 (8) |
C6 | 0.0180 (11) | 0.0134 (10) | 0.0153 (10) | 0.0001 (8) | 0.0110 (9) | −0.0009 (8) |
C7 | 0.0179 (11) | 0.0134 (10) | 0.0180 (11) | −0.0004 (8) | 0.0114 (9) | 0.0011 (9) |
C8 | 0.0212 (11) | 0.0122 (10) | 0.0181 (11) | 0.0025 (8) | 0.0142 (10) | 0.0032 (8) |
C9 | 0.0202 (11) | 0.0183 (11) | 0.0139 (10) | −0.0010 (9) | 0.0099 (9) | 0.0014 (9) |
C10 | 0.0216 (11) | 0.0156 (11) | 0.0186 (11) | −0.0042 (9) | 0.0136 (10) | −0.0009 (9) |
C11 | 0.0187 (11) | 0.0134 (10) | 0.0171 (10) | −0.0025 (9) | 0.0116 (9) | −0.0020 (8) |
C12 | 0.0209 (11) | 0.0161 (11) | 0.0188 (11) | −0.0004 (9) | 0.0143 (9) | −0.0011 (9) |
C13 | 0.0193 (11) | 0.0145 (10) | 0.0145 (10) | 0.0015 (8) | 0.0107 (9) | −0.0008 (8) |
C14 | 0.0196 (11) | 0.0143 (11) | 0.0195 (11) | −0.0024 (9) | 0.0124 (10) | −0.0029 (9) |
C15 | 0.0195 (11) | 0.0143 (11) | 0.0185 (11) | −0.0009 (9) | 0.0127 (9) | 0.0001 (9) |
C16 | 0.0237 (12) | 0.0126 (10) | 0.0211 (11) | −0.0016 (9) | 0.0161 (10) | −0.0019 (9) |
C17 | 0.0226 (12) | 0.0175 (11) | 0.0199 (11) | −0.0007 (9) | 0.0157 (10) | −0.0010 (9) |
C18 | 0.0172 (10) | 0.0156 (11) | 0.0139 (10) | 0.0000 (8) | 0.0090 (9) | −0.0030 (8) |
C19 | 0.0229 (12) | 0.0148 (11) | 0.0185 (11) | −0.0024 (9) | 0.0135 (10) | −0.0019 (9) |
C20 | 0.0210 (11) | 0.0164 (11) | 0.0180 (11) | −0.0023 (9) | 0.0141 (10) | −0.0015 (9) |
Ni—O1 | 2.0494 (19) | C3—C4 | 1.395 (3) |
Ni—O7i | 2.0433 (19) | C3—C8 | 1.478 (3) |
Ni—N1 | 2.160 (2) | C4—C5 | 1.384 (3) |
Ni—N2 | 2.086 (2) | C4—H4 | 0.9500 |
Ni—N3ii | 2.165 (2) | C5—H5 | 0.9500 |
Ni—N4iii | 2.0683 (19) | C6—C7 | 1.378 (3) |
Cr1—O1 | 1.6586 (18) | C6—H6 | 0.9500 |
Cr1—O2 | 1.605 (2) | C7—C8 | 1.389 (3) |
Cr1—O3 | 1.608 (2) | C7—H7 | 0.9500 |
Cr1—O4 | 1.7854 (19) | C8—C9 | 1.393 (3) |
Cr1—Cr2 | 3.1958 (13) | C9—C10 | 1.391 (3) |
Cr2—O4 | 1.7877 (18) | C9—H9 | 0.9500 |
Cr2—O5 | 1.611 (2) | C10—H10 | 0.9500 |
Cr2—O6 | 1.6115 (19) | C11—C12 | 1.383 (3) |
Cr2—O7 | 1.6440 (18) | C11—H11 | 0.9500 |
O7—Niiv | 2.0433 (19) | C12—C13 | 1.396 (3) |
N1—C1 | 1.345 (3) | C12—H12 | 0.9500 |
N1—C5 | 1.351 (3) | C13—C14 | 1.395 (3) |
N2—C15 | 1.342 (3) | C13—C18 | 1.483 (3) |
N2—C11 | 1.349 (3) | C14—C15 | 1.380 (3) |
N3—C20 | 1.345 (3) | C14—H14 | 0.9500 |
N3—C16 | 1.354 (3) | C15—H15 | 0.9500 |
N3—Niv | 2.165 (2) | C16—C17 | 1.379 (3) |
N4—C6 | 1.340 (3) | C16—H16 | 0.9500 |
N4—C10 | 1.344 (3) | C17—C18 | 1.400 (3) |
N4—Nivi | 2.0683 (19) | C17—H17 | 0.9500 |
C1—C2 | 1.389 (3) | C18—C19 | 1.396 (3) |
C1—H1 | 0.9500 | C19—C20 | 1.398 (3) |
C2—C3 | 1.400 (3) | C19—H19 | 0.9500 |
C2—H2 | 0.9500 | C20—H20 | 0.9500 |
O7i—Ni—O1 | 174.48 (7) | C3—C2—H2 | 120.5 |
Cr1—O1—Ni | 137.24 (10) | C4—C3—C2 | 117.6 (2) |
Cr2—O7—Niiv | 156.82 (11) | C4—C3—C8 | 119.6 (2) |
O7i—Ni—N4iii | 91.94 (7) | C2—C3—C8 | 122.8 (2) |
O1—Ni—N4iii | 87.07 (7) | C5—C4—C3 | 119.6 (2) |
O7i—Ni—N2 | 89.42 (7) | C5—C4—H4 | 120.2 |
O1—Ni—N2 | 91.47 (7) | C3—C4—H4 | 120.2 |
N4iii—Ni—N2 | 178.23 (7) | N1—C5—C4 | 123.0 (2) |
O7i—Ni—N1 | 86.81 (7) | N1—C5—H5 | 118.5 |
O1—Ni—N1 | 87.75 (7) | C4—C5—H5 | 118.5 |
N4iii—Ni—N1 | 89.22 (8) | N4—C6—C7 | 122.6 (2) |
N2—Ni—N1 | 89.73 (8) | N4—C6—H6 | 118.7 |
O7i—Ni—N3ii | 87.50 (7) | C7—C6—H6 | 118.7 |
O1—Ni—N3ii | 97.93 (7) | C6—C7—C8 | 120.0 (2) |
N4iii—Ni—N3ii | 90.22 (8) | C6—C7—H7 | 120.0 |
N2—Ni—N3ii | 90.97 (8) | C8—C7—H7 | 120.0 |
N1—Ni—N3ii | 174.25 (7) | C7—C8—C9 | 117.5 (2) |
O2—Cr1—O3 | 109.74 (11) | C7—C8—C3 | 119.7 (2) |
O2—Cr1—O1 | 110.00 (10) | C9—C8—C3 | 122.8 (2) |
O3—Cr1—O1 | 109.82 (10) | C10—C9—C8 | 119.2 (2) |
O2—Cr1—O4 | 107.70 (10) | C10—C9—H9 | 120.4 |
O3—Cr1—O4 | 110.74 (9) | C8—C9—H9 | 120.4 |
O1—Cr1—O4 | 108.82 (9) | N4—C10—C9 | 122.5 (2) |
O2—Cr1—Cr2 | 127.84 (8) | N4—C10—H10 | 118.8 |
O3—Cr1—Cr2 | 86.11 (7) | C9—C10—H10 | 118.8 |
O1—Cr1—Cr2 | 110.12 (6) | N2—C11—C12 | 123.0 (2) |
O4—Cr1—Cr2 | 26.59 (6) | N2—C11—H11 | 118.5 |
O5—Cr2—O6 | 109.82 (11) | C12—C11—H11 | 118.5 |
O5—Cr2—O7 | 109.93 (10) | C11—C12—C13 | 119.2 (2) |
O6—Cr2—O7 | 110.28 (10) | C11—C12—H12 | 120.4 |
O5—Cr2—O4 | 109.69 (10) | C13—C12—H12 | 120.4 |
O6—Cr2—O4 | 106.81 (10) | C14—C13—C12 | 117.3 (2) |
O7—Cr2—O4 | 110.26 (9) | C14—C13—C18 | 121.3 (2) |
O5—Cr2—Cr1 | 96.62 (8) | C12—C13—C18 | 121.3 (2) |
O6—Cr2—Cr1 | 133.32 (8) | C15—C14—C13 | 120.0 (2) |
O7—Cr2—Cr1 | 94.83 (6) | C15—C14—H14 | 120.0 |
O4—Cr2—Cr1 | 26.55 (6) | C13—C14—H14 | 120.0 |
Cr1—O4—Cr2 | 126.86 (10) | N2—C15—C14 | 122.6 (2) |
C1—N1—C5 | 117.07 (19) | N2—C15—H15 | 118.7 |
C1—N1—Ni | 124.13 (15) | C14—C15—H15 | 118.7 |
C5—N1—Ni | 118.14 (15) | N3—C16—C17 | 123.5 (2) |
C15—N2—C11 | 117.69 (19) | N3—C16—H16 | 118.3 |
C15—N2—Ni | 121.52 (15) | C17—C16—H16 | 118.3 |
C11—N2—Ni | 120.59 (15) | C16—C17—C18 | 119.7 (2) |
C20—N3—C16 | 116.64 (19) | C16—C17—H17 | 120.2 |
C20—N3—Niv | 125.91 (15) | C18—C17—H17 | 120.2 |
C16—N3—Niv | 117.40 (15) | C19—C18—C17 | 117.4 (2) |
C6—N4—C10 | 118.12 (19) | C19—C18—C13 | 123.6 (2) |
C6—N4—Nivi | 118.60 (15) | C17—C18—C13 | 118.9 (2) |
C10—N4—Nivi | 123.21 (16) | C18—C19—C20 | 119.0 (2) |
N1—C1—C2 | 123.5 (2) | C18—C19—H19 | 120.5 |
N1—C1—H1 | 118.3 | C20—C19—H19 | 120.5 |
C2—C1—H1 | 118.3 | N3—C20—C19 | 123.6 (2) |
C1—C2—C3 | 118.9 (2) | N3—C20—H20 | 118.2 |
C1—C2—H2 | 120.5 | C19—C20—H20 | 118.2 |
Symmetry codes: (i) x−1/2, −y+1/2, z−1/2; (ii) x, −y, z+1/2; (iii) x, −y+1, z+1/2; (iv) x+1/2, −y+1/2, z+1/2; (v) x, −y, z−1/2; (vi) x, −y+1, z−1/2. |
[Cu(C10H8N2)2(Cr2O7)] | F(000) = 2376 |
Mr = 591.91 | Dx = 1.817 Mg m−3 Dm = 1.828 (5) Mg m−3 Dm measured by flotation pycnometry |
Monoclinic, C_1_2/c_1 | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -C 2yc | Cell parameters from 5221 reflections |
a = 21.603 (3) Å | θ = 4–28° |
b = 14.8505 (18) Å | µ = 2.01 mm−1 |
c = 16.604 (2) Å | T = 153 K |
β = 125.682 (2)° | Cube, green |
V = 4326.8 (10) Å3 | 0.15 × 0.15 × 0.14 mm |
Z = 8 |
Bruker SMART AXS diffractometer | 5221 independent reflections |
Radiation source: fine-focus sealed tube | 4526 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.026 |
ω–2θ scans | θmax = 28.3°, θmin = 1.8° |
Absorption correction: analytical face indexed | h = −28→27 |
Tmin = 0.769, Tmax = 0.816 | k = −19→19 |
19193 measured reflections | l = −21→22 |
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)] = 0.031 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.085 | H-atom parameters constrained |
S = 1.06 | w = 1/[σ2(Fo2) + (0.047P)2 + 7.1233P] where P = (Fo2 + 2Fc2)/3 |
5221 reflections | (Δ/σ)max = 0.001 |
307 parameters | Δρmax = 0.73 e Å−3 |
0 restraints | Δρmin = −0.78 e Å−3 |
[Cu(C10H8N2)2(Cr2O7)] | V = 4326.8 (10) Å3 |
Mr = 591.91 | Z = 8 |
Monoclinic, C_1_2/c_1 | Mo Kα radiation |
a = 21.603 (3) Å | µ = 2.01 mm−1 |
b = 14.8505 (18) Å | T = 153 K |
c = 16.604 (2) Å | 0.15 × 0.15 × 0.14 mm |
β = 125.682 (2)° |
Bruker SMART AXS diffractometer | 5221 independent reflections |
Absorption correction: analytical face indexed | 4526 reflections with I > 2σ(I) |
Tmin = 0.769, Tmax = 0.816 | Rint = 0.026 |
19193 measured reflections |
R[F2 > 2σ(F2)] = 0.031 | 0 restraints |
wR(F2) = 0.085 | H-atom parameters constrained |
S = 1.06 | Δρmax = 0.73 e Å−3 |
5221 reflections | Δρmin = −0.78 e Å−3 |
307 parameters |
Experimental. Stationary background counts were recorded at each end of the scan, and the scan time:background time ratio was 2:1. |
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. |
x | y | z | Uiso*/Ueq | ||
Cu | 0.135200 (13) | 0.251166 (14) | 0.621092 (16) | 0.01239 (8) | |
Cr1 | 0.335441 (18) | 0.20572 (2) | 0.77490 (2) | 0.01886 (9) | |
Cr2 | 0.419807 (19) | 0.26282 (2) | 1.00090 (2) | 0.01688 (9) | |
O1 | 0.26508 (8) | 0.27596 (11) | 0.70369 (11) | 0.0210 (3) | |
O2 | 0.31226 (10) | 0.10670 (12) | 0.72644 (13) | 0.0335 (4) | |
O3 | 0.41134 (9) | 0.23950 (13) | 0.78674 (13) | 0.0312 (4) | |
O4 | 0.35066 (8) | 0.19990 (11) | 0.89264 (11) | 0.0221 (3) | |
O5 | 0.39622 (11) | 0.36783 (11) | 0.98379 (14) | 0.0362 (4) | |
O6 | 0.42047 (10) | 0.22367 (12) | 1.09203 (12) | 0.0296 (4) | |
O7 | 0.50347 (9) | 0.25031 (10) | 1.02384 (12) | 0.0211 (3) | |
N1 | 0.12198 (9) | 0.35858 (11) | 0.52904 (12) | 0.0147 (3) | |
N2 | 0.13276 (9) | 0.16381 (11) | 0.52695 (12) | 0.0140 (3) | |
N3 | 0.13121 (9) | −0.14545 (11) | 0.20216 (12) | 0.0147 (3) | |
N4 | 0.14071 (9) | 0.66020 (11) | 0.21516 (12) | 0.0135 (3) | |
C1 | 0.15453 (11) | 0.43983 (13) | 0.56358 (14) | 0.0167 (4) | |
H1 | 0.1763 | 0.4536 | 0.6310 | 0.020* | |
C2 | 0.15807 (11) | 0.50457 (13) | 0.50618 (14) | 0.0170 (4) | |
H2 | 0.1796 | 0.5621 | 0.5329 | 0.020* | |
C3 | 0.12939 (11) | 0.48343 (13) | 0.40829 (14) | 0.0156 (4) | |
C4 | 0.09333 (11) | 0.40042 (13) | 0.37136 (14) | 0.0164 (4) | |
H4 | 0.0721 | 0.3843 | 0.3046 | 0.020* | |
C5 | 0.08864 (11) | 0.34191 (13) | 0.43209 (14) | 0.0162 (4) | |
H5 | 0.0608 | 0.2876 | 0.4045 | 0.019* | |
C6 | 0.08085 (11) | 0.60554 (13) | 0.18120 (14) | 0.0157 (4) | |
H6 | 0.0401 | 0.6070 | 0.1126 | 0.019* | |
C7 | 0.07645 (11) | 0.54754 (13) | 0.24207 (14) | 0.0164 (4) | |
H7 | 0.0337 | 0.5089 | 0.2153 | 0.020* | |
C8 | 0.13493 (11) | 0.54549 (13) | 0.34331 (14) | 0.0158 (4) | |
C9 | 0.19715 (11) | 0.60211 (13) | 0.37821 (14) | 0.0177 (4) | |
H9 | 0.2383 | 0.6025 | 0.4466 | 0.021* | |
C10 | 0.19846 (11) | 0.65783 (13) | 0.31234 (14) | 0.0169 (4) | |
H10 | 0.2415 | 0.6955 | 0.3365 | 0.020* | |
C11 | 0.18575 (11) | 0.16864 (13) | 0.50864 (14) | 0.0167 (4) | |
H11 | 0.2268 | 0.2098 | 0.5459 | 0.020* | |
C12 | 0.18271 (11) | 0.11611 (13) | 0.43771 (15) | 0.0171 (4) | |
H12 | 0.2198 | 0.1233 | 0.4247 | 0.021* | |
C13 | 0.12503 (11) | 0.05265 (13) | 0.38557 (14) | 0.0159 (4) | |
C14 | 0.06949 (12) | 0.04895 (14) | 0.40375 (15) | 0.0181 (4) | |
H14 | 0.0284 | 0.0076 | 0.3683 | 0.022* | |
C15 | 0.07463 (11) | 0.10555 (13) | 0.47342 (14) | 0.0171 (4) | |
H15 | 0.0359 | 0.1033 | 0.4839 | 0.021* | |
C16 | 0.09949 (12) | −0.16223 (13) | 0.25043 (15) | 0.0177 (4) | |
H16 | 0.0779 | −0.2200 | 0.2433 | 0.021* | |
C17 | 0.09685 (12) | −0.09950 (13) | 0.30989 (14) | 0.0180 (4) | |
H17 | 0.0761 | −0.1154 | 0.3450 | 0.022* | |
C18 | 0.12486 (11) | −0.01267 (13) | 0.31802 (14) | 0.0159 (4) | |
C19 | 0.15445 (12) | 0.00679 (13) | 0.26421 (15) | 0.0185 (4) | |
H19 | 0.1720 | 0.0657 | 0.2651 | 0.022* | |
C20 | 0.15771 (11) | −0.06132 (14) | 0.20948 (14) | 0.0178 (4) | |
H20 | 0.1798 | −0.0480 | 0.1754 | 0.021* |
U11 | U22 | U33 | U12 | U13 | U23 | |
Cu | 0.01714 (13) | 0.01155 (12) | 0.01110 (12) | 0.00053 (8) | 0.00971 (11) | 0.00007 (8) |
Cr1 | 0.01455 (16) | 0.02398 (18) | 0.01634 (16) | 0.00120 (12) | 0.00804 (14) | −0.00423 (12) |
Cr2 | 0.01653 (17) | 0.01879 (17) | 0.01471 (16) | 0.00125 (12) | 0.00876 (14) | 0.00033 (11) |
O1 | 0.0188 (7) | 0.0258 (8) | 0.0173 (7) | 0.0022 (6) | 0.0098 (6) | −0.0010 (6) |
O2 | 0.0314 (9) | 0.0280 (9) | 0.0336 (9) | 0.0045 (7) | 0.0147 (8) | −0.0105 (7) |
O3 | 0.0170 (8) | 0.0529 (11) | 0.0248 (9) | −0.0019 (7) | 0.0128 (7) | −0.0042 (7) |
O4 | 0.0182 (7) | 0.0286 (8) | 0.0169 (7) | −0.0041 (6) | 0.0088 (6) | −0.0016 (6) |
O5 | 0.0455 (11) | 0.0219 (8) | 0.0390 (10) | 0.0113 (8) | 0.0233 (9) | 0.0017 (7) |
O6 | 0.0318 (9) | 0.0387 (9) | 0.0231 (8) | −0.0023 (8) | 0.0187 (7) | 0.0005 (7) |
O7 | 0.0146 (7) | 0.0278 (8) | 0.0180 (7) | −0.0015 (5) | 0.0078 (6) | 0.0012 (5) |
N1 | 0.0151 (8) | 0.0155 (8) | 0.0138 (7) | 0.0000 (6) | 0.0085 (7) | 0.0018 (6) |
N2 | 0.0170 (8) | 0.0128 (7) | 0.0126 (7) | 0.0019 (6) | 0.0089 (6) | 0.0007 (6) |
N3 | 0.0167 (8) | 0.0157 (8) | 0.0135 (7) | −0.0010 (6) | 0.0098 (7) | −0.0014 (6) |
N4 | 0.0176 (8) | 0.0122 (7) | 0.0141 (7) | 0.0007 (6) | 0.0110 (7) | 0.0004 (6) |
C1 | 0.0191 (9) | 0.0182 (9) | 0.0141 (9) | −0.0009 (7) | 0.0104 (8) | −0.0006 (7) |
C2 | 0.0192 (9) | 0.0147 (9) | 0.0178 (9) | −0.0023 (7) | 0.0112 (8) | −0.0003 (7) |
C3 | 0.0148 (9) | 0.0171 (9) | 0.0165 (9) | 0.0023 (7) | 0.0099 (8) | 0.0034 (7) |
C4 | 0.0173 (9) | 0.0174 (9) | 0.0137 (9) | 0.0014 (7) | 0.0085 (8) | 0.0003 (7) |
C5 | 0.0168 (9) | 0.0149 (9) | 0.0151 (9) | 0.0004 (7) | 0.0083 (8) | 0.0009 (7) |
C6 | 0.0171 (9) | 0.0163 (9) | 0.0144 (9) | 0.0008 (7) | 0.0097 (8) | −0.0002 (7) |
C7 | 0.0169 (9) | 0.0168 (9) | 0.0165 (9) | −0.0007 (7) | 0.0103 (8) | 0.0007 (7) |
C8 | 0.0195 (9) | 0.0147 (9) | 0.0171 (9) | 0.0020 (7) | 0.0129 (8) | 0.0022 (7) |
C9 | 0.0194 (10) | 0.0189 (9) | 0.0125 (9) | −0.0008 (7) | 0.0079 (8) | 0.0011 (7) |
C10 | 0.0180 (9) | 0.0173 (9) | 0.0157 (9) | −0.0036 (7) | 0.0100 (8) | −0.0006 (7) |
C11 | 0.0174 (9) | 0.0171 (9) | 0.0154 (9) | −0.0017 (7) | 0.0093 (8) | −0.0020 (7) |
C12 | 0.0186 (9) | 0.0189 (9) | 0.0177 (9) | 0.0001 (7) | 0.0127 (8) | −0.0013 (7) |
C13 | 0.0186 (9) | 0.0165 (9) | 0.0128 (8) | 0.0003 (7) | 0.0092 (8) | −0.0010 (7) |
C14 | 0.0196 (10) | 0.0172 (9) | 0.0184 (9) | −0.0020 (7) | 0.0116 (8) | −0.0028 (7) |
C15 | 0.0203 (10) | 0.0164 (9) | 0.0183 (9) | −0.0009 (7) | 0.0133 (8) | −0.0002 (7) |
C16 | 0.0206 (9) | 0.0162 (9) | 0.0190 (9) | −0.0017 (7) | 0.0131 (8) | −0.0019 (7) |
C17 | 0.0217 (10) | 0.0181 (9) | 0.0184 (9) | −0.0010 (8) | 0.0141 (8) | −0.0016 (7) |
C18 | 0.0167 (9) | 0.0171 (9) | 0.0136 (8) | 0.0005 (7) | 0.0086 (8) | −0.0014 (7) |
C19 | 0.0224 (10) | 0.0161 (9) | 0.0184 (9) | −0.0033 (8) | 0.0128 (8) | −0.0025 (7) |
C20 | 0.0206 (10) | 0.0195 (9) | 0.0165 (9) | −0.0018 (7) | 0.0126 (8) | −0.0015 (7) |
Cu—O1 | 2.3238 (15) | C3—C8 | 1.476 (3) |
Cu—O7i | 2.3120 (16) | C4—C5 | 1.379 (3) |
Cu—N1 | 2.1102 (16) | C4—H4 | 0.95 |
Cu—N2 | 2.0082 (16) | C5—H5 | 0.95 |
Cu—N3ii | 2.1022 (16) | C6—C7 | 1.373 (3) |
Cu—N4iii | 1.9923 (16) | C6—H6 | 0.95 |
Cr1—O1 | 1.6432 (15) | C7—C8 | 1.395 (3) |
Cr1—O2 | 1.6095 (17) | C7—H7 | 0.95 |
Cr1—O3 | 1.6132 (17) | C8—C9 | 1.393 (3) |
Cr1—O4 | 1.7855 (15) | C9—C10 | 1.385 (3) |
Cr2—O4 | 1.7898 (15) | C9—H9 | 0.95 |
Cr2—O5 | 1.6135 (17) | C10—H10 | 0.95 |
Cr2—O6 | 1.6132 (16) | C11—C12 | 1.382 (3) |
Cr2—O7 | 1.6258 (16) | C11—H11 | 0.95 |
O7—Cuiv | 2.3120 (16) | C12—C13 | 1.390 (3) |
N1—C1 | 1.345 (3) | C12—H12 | 0.95 |
N1—C5 | 1.349 (2) | C13—C14 | 1.399 (3) |
N2—C15 | 1.347 (3) | C13—C18 | 1.481 (3) |
N2—C11 | 1.347 (2) | C14—C15 | 1.381 (3) |
N3—C20 | 1.350 (3) | C14—H14 | 0.95 |
N3—C16 | 1.347 (2) | C15—H15 | 0.95 |
N3—Cuv | 2.1022 (16) | C16—C17 | 1.382 (3) |
N4—C6 | 1.341 (2) | C16—H16 | 0.95 |
N4—C10 | 1.347 (2) | C17—C18 | 1.397 (3) |
N4—Cuvi | 1.9923 (16) | C17—H17 | 0.95 |
C1—C2 | 1.387 (3) | C18—C19 | 1.399 (3) |
C1—H1 | 0.95 | C19—C20 | 1.389 (3) |
C2—C3 | 1.396 (3) | C19—H19 | 0.95 |
C2—H2 | 0.95 | C20—H20 | 0.95 |
C3—C4 | 1.395 (3) | ||
O7i—Cu—O1 | 169.82 (6) | C5—C4—C3 | 119.73 (18) |
Cr1—O1—Cu | 128.01 (9) | C5—C4—H4 | 120.1 |
Cr2—O7—Cuiv | 155.78 (9) | C3—C4—H4 | 120.1 |
N4iii—Cu—N2 | 178.06 (7) | C4—C5—N1 | 122.78 (18) |
N4iii—Cu—N3ii | 89.85 (7) | C4—C5—H5 | 118.6 |
N2—Cu—N3ii | 91.36 (6) | N1—C5—H5 | 118.6 |
N4iii—Cu—N1 | 89.39 (7) | C7—C6—N4 | 122.29 (18) |
N2—Cu—N1 | 89.63 (6) | C7—C6—H6 | 118.9 |
N3ii—Cu—N1 | 171.70 (6) | N4—C6—H6 | 118.9 |
N4iii—Cu—O7i | 92.30 (6) | C6—C7—C8 | 119.86 (18) |
N2—Cu—O7i | 89.28 (6) | C6—C7—H7 | 120.1 |
N3ii—Cu—O7i | 86.94 (6) | C8—C7—H7 | 120.1 |
N1—Cu—O7i | 84.83 (6) | C9—C8—C7 | 117.66 (17) |
N4iii—Cu—O1 | 86.17 (6) | C9—C8—C3 | 122.86 (18) |
N2—Cu—O1 | 92.08 (6) | C7—C8—C3 | 119.47 (18) |
N3ii—Cu—O1 | 103.11 (6) | C10—C9—C8 | 119.43 (18) |
N1—Cu—O1 | 85.09 (6) | C10—C9—H9 | 120.3 |
O2—Cr1—O3 | 110.05 (9) | C8—C9—H9 | 120.3 |
O2—Cr1—O1 | 109.44 (8) | C9—C10—N4 | 122.04 (18) |
O3—Cr1—O1 | 109.76 (9) | C9—C10—H10 | 119.0 |
O2—Cr1—O4 | 107.94 (9) | N4—C10—H10 | 119.0 |
O3—Cr1—O4 | 110.90 (8) | C12—C11—N2 | 122.56 (18) |
O1—Cr1—O4 | 108.71 (7) | C12—C11—H11 | 118.7 |
O6—Cr2—O5 | 110.04 (10) | N2—C11—H11 | 118.7 |
O6—Cr2—O7 | 109.79 (8) | C11—C12—C13 | 119.55 (18) |
O5—Cr2—O7 | 110.21 (9) | C11—C12—H12 | 120.2 |
O6—Cr2—O4 | 107.42 (8) | C13—C12—H12 | 120.2 |
O5—Cr2—O4 | 109.56 (9) | C12—C13—C14 | 117.55 (17) |
O7—Cr2—O4 | 109.77 (7) | C12—C13—C18 | 121.39 (17) |
Cr1—O4—Cr2 | 125.96 (9) | C14—C13—C18 | 120.94 (18) |
C1—N1—C5 | 117.13 (16) | C15—C14—C13 | 119.80 (18) |
C1—N1—Cu | 123.58 (13) | C15—C14—H14 | 120.1 |
C5—N1—Cu | 118.57 (13) | C13—C14—H14 | 120.1 |
C15—N2—C11 | 118.26 (16) | C14—C15—N2 | 122.16 (18) |
C15—N2—Cu | 121.31 (13) | C14—C15—H15 | 118.9 |
C11—N2—Cu | 120.09 (13) | N2—C15—H15 | 118.9 |
C20—N3—C16 | 116.99 (17) | N3—C16—C17 | 123.18 (18) |
C20—N3—Cuv | 125.11 (13) | N3—C16—H16 | 118.4 |
C16—N3—Cuv | 117.90 (13) | C17—C16—H16 | 118.4 |
C6—N4—C10 | 118.70 (16) | C16—C17—C18 | 119.67 (18) |
C6—N4—Cuvi | 117.92 (13) | C16—C17—H17 | 120.2 |
C10—N4—Cuvi | 123.14 (13) | C18—C17—H17 | 120.2 |
N1—C1—C2 | 123.61 (18) | C17—C18—C19 | 117.55 (17) |
N1—C1—H1 | 118.2 | C17—C18—C13 | 119.16 (17) |
C2—C1—H1 | 118.2 | C19—C18—C13 | 123.24 (18) |
C1—C2—C3 | 118.64 (18) | C20—C19—C18 | 118.95 (18) |
C1—C2—H2 | 120.7 | C20—C19—H19 | 120.5 |
C3—C2—H2 | 120.7 | C18—C19—H19 | 120.5 |
C4—C3—C2 | 117.74 (17) | N3—C20—C19 | 123.52 (18) |
C4—C3—C8 | 119.54 (18) | N3—C20—H20 | 118.2 |
C2—C3—C8 | 122.71 (18) | C19—C20—H20 | 118.2 |
Symmetry codes: (i) x−1/2, −y+1/2, z−1/2; (ii) x, −y, z+1/2; (iii) x, −y+1, z+1/2; (iv) x+1/2, −y+1/2, z+1/2; (v) x, −y, z−1/2; (vi) x, −y+1, z−1/2. |
Experimental details
(I) | (II) | |
Crystal data | ||
Chemical formula | [Ni(C10H8N2)2(Cr2O7)] | [Cu(C10H8N2)2(Cr2O7)] |
Mr | 587.08 | 591.91 |
Crystal system, space group | Monoclinic, C_1_2/c_1 | Monoclinic, C_1_2/c_1 |
Temperature (K) | 153 | 153 |
a, b, c (Å) | 21.343 (7), 15.260 (5), 16.658 (6) | 21.603 (3), 14.8505 (18), 16.604 (2) |
β (°) | 127.094 (5) | 125.682 (2) |
V (Å3) | 4328 (3) | 4326.8 (10) |
Z | 8 | 8 |
Radiation type | Mo Kα | Mo Kα |
µ (mm−1) | 1.90 | 2.01 |
Crystal size (mm) | 0.21 × 0.16 × 0.15 | 0.15 × 0.15 × 0.14 |
Data collection | ||
Diffractometer | Bruker SMART AXS diffractometer | Bruker SMART AXS diffractometer |
Absorption correction | Analytical face-indexed (reference?) | Analytical face indexed |
Tmin, Tmax | 0.718, 0.874 | 0.769, 0.816 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 19357, 5184, 4364 | 19193, 5221, 4526 |
Rint | 0.083 | 0.026 |
(sin θ/λ)max (Å−1) | 0.667 | 0.667 |
Refinement | ||
R[F2 > 2σ(F2)], wR(F2), S | 0.038, 0.099, 1.08 | 0.031, 0.085, 1.06 |
No. of reflections | 5184 | 5221 |
No. of parameters | 307 | 307 |
H-atom treatment | H-atom parameters constrained | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 1.19, −0.64 | 0.73, −0.78 |
Computer programs: SMART-NT (Siemens, 1996), SAINT-Plus (Siemens, 1996), SAINT-Plus, SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), ATOMS (Dowty, 1999), program (reference)?.
Ni—O1 | 2.0494 (19) | Cr1—O2 | 1.605 (2) |
Ni—O7i | 2.0433 (19) | Cr1—O3 | 1.608 (2) |
Ni—N1 | 2.160 (2) | Cr1—O4 | 1.7854 (19) |
Ni—N2 | 2.086 (2) | Cr2—O4 | 1.7877 (18) |
Ni—N3ii | 2.165 (2) | Cr2—O5 | 1.611 (2) |
Ni—N4iii | 2.0683 (19) | Cr2—O6 | 1.6115 (19) |
Cr1—O1 | 1.6586 (18) | Cr2—O7 | 1.6440 (18) |
O7i—Ni—O1 | 174.48 (7) | O1—Cr1—O4 | 108.82 (9) |
Cr1—O1—Ni | 137.24 (10) | O5—Cr2—O6 | 109.82 (11) |
Cr2—O7—Niiv | 156.82 (11) | O5—Cr2—O7 | 109.93 (10) |
O2—Cr1—O3 | 109.74 (11) | O6—Cr2—O7 | 110.28 (10) |
O2—Cr1—O1 | 110.00 (10) | O5—Cr2—O4 | 109.69 (10) |
O3—Cr1—O1 | 109.82 (10) | O6—Cr2—O4 | 106.81 (10) |
O2—Cr1—O4 | 107.70 (10) | O7—Cr2—O4 | 110.26 (9) |
O3—Cr1—O4 | 110.74 (9) | Cr1—O4—Cr2 | 126.86 (10) |
Symmetry codes: (i) x−1/2, −y+1/2, z−1/2; (ii) x, −y, z+1/2; (iii) x, −y+1, z+1/2; (iv) x+1/2, −y+1/2, z+1/2. |
Cu—O1 | 2.3238 (15) | Cr1—O2 | 1.6095 (17) |
Cu—O7i | 2.3120 (16) | Cr1—O3 | 1.6132 (17) |
Cu—N1 | 2.1102 (16) | Cr1—O4 | 1.7855 (15) |
Cu—N2 | 2.0082 (16) | Cr2—O4 | 1.7898 (15) |
Cu—N3ii | 2.1022 (16) | Cr2—O5 | 1.6135 (17) |
Cu—N4iii | 1.9923 (16) | Cr2—O6 | 1.6132 (16) |
Cr1—O1 | 1.6432 (15) | Cr2—O7 | 1.6258 (16) |
O7i—Cu—O1 | 169.82 (6) | O1—Cr1—O4 | 108.71 (7) |
Cr1—O1—Cu | 128.01 (9) | O6—Cr2—O5 | 110.04 (10) |
Cr2—O7—Cuiv | 155.78 (9) | O6—Cr2—O7 | 109.79 (8) |
O2—Cr1—O3 | 110.05 (9) | O5—Cr2—O7 | 110.21 (9) |
O2—Cr1—O1 | 109.44 (8) | O6—Cr2—O4 | 107.42 (8) |
O3—Cr1—O1 | 109.76 (9) | O5—Cr2—O4 | 109.56 (9) |
O2—Cr1—O4 | 107.94 (9) | O7—Cr2—O4 | 109.77 (7) |
O3—Cr1—O4 | 110.90 (8) | Cr1—O4—Cr2 | 125.96 (9) |
Symmetry codes: (i) x−1/2, −y+1/2, z−1/2; (ii) x, −y, z+1/2; (iii) x, −y+1, z+1/2; (iv) x+1/2, −y+1/2, z+1/2. |
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Non-centrosymmetric solids, i.e. those without a center of inversion, may exhibit one or more interesting physical properties, such as ferroelectricity, pyroelectricity or piezoelectricity. A current approach to synthesizing non-centrosymmetric structures is to begin with asymmetric `building blocks' (Halasyamani & Poeppelmeier, 1998). One example of an asymmetric building block is the dichromate anion, Cr2O72−, which is found in the compounds M(py)4Cr2O7 (M = Cu2+ and Zn2+, and py is pyridine) (Norquist et al., 2001). These compounds consist of alternating vertex-linked CuN4O2 octahedra and Cr2O72− polyhedra that form linear chain structures. In contrast, the dichromate–containing Cu(2,2'–bpy)2Cr2O7 (bpy is bipyridine) forms isolated molecular species rather than chains (Maggard et al., 2002). Both left- and right-handed enantiomers of isolated Cu(2,2'–bpy)2Cr2O7 molecules pack with inversion symmetry between layers in space group P1. The structural difference between Cu(py)4Cr2O7 and Cu(2,2'–bpy)2Cr2O7 appears to be due to the modification evinced by the change of ligand. The different structures of the two compounds highlight the necessity of further studies to characterize the structure-directing features of organic mono- and bidentate ligands in relation to the dichromate anion. Presented here is continuing synthetic work employing the late transition metal oxides of nickel and copper with asymmetric dichromate species (also referred to as the anion) and the 4,4'–bipyridine (4,4'–bpy) ligand.
Ni(4,4'–bpy)2Cr2O7, (I), and Cu(4,4'–bpy)2Cr2O7, (II), are isostructural compounds. An ellipsoid plot is shown in Fig. 1. The bond lengths and angles of the dichromate anion in both (I) and (II) (Tables 1 and 2) are in good agreement with those reported for Na2Cr2O7 (Panagiotopoulos & Brown, 1972). In both (I) and (II), a three-dimensional structure is generated from two bonding motifs, viz. a linear chain that consists of alternating late transition metal centered octahedra joined to Cr2O72− polyhedra, as shown in Fig. 2, and a two–dimensional square net of type (4,4) (Wells, 1977) composed of late transition metal cations coordinated by 4,4'–bpy ligands along the [200] plane (perpendicular to the chain; Fig. 3). The late transition metal cations are also bonded to O-atom vertices of the dichromate anions in a trans fashion. These opposing vertices are also designated as the axial positions of the octahedra. As expected, the Cu—O bonds in (II) are elongated owing to the Jahn–Teller distortion of the Cu2+ ion. The average bond length between Cu and N atoms is 2.05 Å, while the average bond length of the Cu–O bonds is 2.32 Å. In comparison, Ni2+ has on average longer M—N bonds (2.12 Å) and shorter M–O bonds (2.02 Å). A general feature of the M–N bonds in both structures is that one M–N bond, for example M—N1 (M = Ni, Cu) of a 4,4'–bpy, is longer than the second M—N bond (M—N4) of the same 4,4'–bpy (Fig. 1, and Tables 1 and 2). The difference between the two bonds is approximately 0.1 Å for both 4,4'–bipyridine ligands of (I) and (II). Similarly, for both (I) and (II), the shorter M—N bonds are trans to one another, as are the two longer M—N bonds. There are other examples of octahedrally coordinated Ni and Cu atoms having four bonds to N atoms and two bonds to O atoms exhibiting a similar trend (Prout et al., 1971; Kulynych & Shimizu, 2002; Fritsky et al., 2004]. A search of the Cambridge Structural Database revealed that for octahedrally coordinated M (M = Cu and Ni) with four N-containing heterocyclic ligands and two O-containing ligands there is a correlation between the ionic character of the M—O bond (carbonate or dichromate versus water for example) and the variation of length within the four M—N bonds (Allen, 2002). The differences in M—O and M—N bond lengths of the title compounds are also accompanied by other distortions, such as a small displacement of the 4,4'–bpy molecule with respect to the equatorial plane.
Both compounds have chain structures composed of a late transition metal and coordinated dichromates. The chains are parallel to one another in the [–100] direction. Along the 21 screw axis there is a 180° rotation of each dichromate anion as the chain propagates; thus the repeating segment in a chain is composed of two cations and two anions (Fig. 2).
The second bonding motif in M(bpy)4Cr2O7 (M = Ni2+, Cu2+) is a two–dimensional (4,4)-net composed of the bridging ligands and the late transition metal atoms. Each Ni/Cu atom forms bonds to four 4,4'–bpy ligands in the equatorial positions. These ligands serve as linkers and bridge each Ni/Cu atom to four other Ni/Cu–centered octahedra (Fig. 3). The linking of octahedra creates a two–dimensional square net composed of Ni2+/Cu2+ cations and 4,4'–bpy ligands.
The combination of this square net with the linear chain motif results in a three-dimensional net where the points of connectivity for both motifs is the Ni2+/Cu2+-centered octahedra (n = 6) (Wells, 1977). The ligands act as spacers between the Ni2+/Cu2+-centered octahedra centers. Each three-dimensional net is non-centrosymmetric with large cavities (7.0 × 7.0 × 5.0 Å), owing to the physical size and rigidity of the linking ligands. When a single non-centrosymmetric three-dimensional net is considered, the net is compatible with the polar or chiral-polar space group Cc or C2, respectively. However, the title compounds crystallize in the centrosymmetric space group C2/c, which indicates that the structures are composed of more than one three-dimensional net.
Each parallel chain of late transition metal atoms and coordinated dichromate anions is surrounded by four other chains. These four surrounding chains are related to the central chain by an inversion center. The relationship between neighboring chains is shown in Fig. 4. Note that the Cr-centered tetrahedra have opposing facial directions. Additionally, the four closest neighboring chains are offset from the central chain by one-quater of the repeating segment along the chain propagation direction. The chains of the net are related to their neighbors by an inversion center and, in three dimensions, the entire non-centrosymmetric three-dimensional net is related to the second net by an inversion center. In addition, the second independent three-dimensional net effectively fills the cavities as it interpenetrates the first net (Fig. 5).
It is evident that the three-dimensional net is created from late transition metal cations with coordinated dichromate anions in one direction and, most importantly, the linking 4,4'-bipyridyl ligands in the other two directions. The rigidity and bidentate characteristics of 4,4'-bpy and dichromate bring about a stable three-dimensional net, while the length of the ligands affords enough space in the net to accommodate the interpenetration of an inversely related three-dimensional net.