Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270102009460/bk1651sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S0108270102009460/bk1651Isup2.hkl |
CCDC reference: 192947
The precursor compound, [Rh2{O2CC6H2(OC2H5)3}4], was synthesized from commercial [Rh2(O2CCH3)4] by a metathesis reaction in a twofold excess of the molten ligand for 4 h under an N2 atmosphere. The compound was purified by washing with hot methanol and then by dissolving in CHCl3 and adding methanol until precipitation of the light blue methanolic bisadduct. Finally, the precipitate was dried under vacuum at 353 K until a green solid was obtained, due to the release of the axial ligands. When an excess of pyrazine was added to a solution of the complex in acetone, the solution immediately became red. Red crystals of (I) were obtained by slow evaporation of the solvent, and were kept in contact with the mother liquor in order to prevent loss of pyrazine and subsequent degradation. This instability made other physicochemical essays difficult.
All H atoms were located among the first 45 peaks of a difference Fourier map, but were positioned stereochemically and refined with a riding model, with C—H = 0.95–0.99 Å. Are these the correct constraints? Methyl H atoms were treated as rigid bodies and allowed to rotate around the corresponding C—C bond. The largest peak and trough of the final difference map were located 1.23 Å and 0.94 Å, respectively, from the Rh atom.
Data collection: COLLECT (Nonius, 1997); cell refinement: HKL SCALEPACK (Otwinowski & Minor 1997); data reduction: HKL DENZO (Otwinowski & Minor 1997) and SCALEPACK; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEPII (Johnson, 1976); software used to prepare material for publication: SHELXL97.
[Rh2(C13H17O5)4(C4H4N2)2] | Z = 1 |
Mr = 1379.07 | F(000) = 714 |
Triclinic, P1 | Dx = 1.498 Mg m−3 |
Hall symbol: -P 1 | Mo Kα radiation, λ = 0.71073 Å |
a = 7.780 (1) Å | Cell parameters from 21034 reflections |
b = 13.056 (1) Å | θ = 1.0–27.5° |
c = 15.245 (1) Å | µ = 0.62 mm−1 |
α = 97.04 (1)° | T = 100 K |
β = 93.48 (1)° | Prism, red |
γ = 94.23 (1)° | 0.10 × 0.05 × 0.04 mm |
V = 1528.9 (3) Å3 |
Nonius KappaCCD area-detector diffractometer | 5375 independent reflections |
Radiation source: fine-focus sealed tube | 4778 reflections with I > 2σ(I) |
Horizonally mounted graphite crystal monochromator | Rint = 0.090 |
Detector resolution: 9 pixels mm-1 | θmax = 25.0°, θmin = 2.6° |
ϕ and ω scans | h = −9→9 |
Absorption correction: numerical (Coppens et al., 1965) | k = −15→15 |
Tmin = 0.930, Tmax = 0.979 | l = −18→18 |
19184 measured reflections |
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)] = 0.034 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.087 | H-atom parameters constrained |
S = 1.06 | w = 1/[σ2(Fo2) + (0.0312P)2 + 1.2037P] where P = (Fo2 + 2Fc2)/3 |
5375 reflections | (Δ/σ)max = 0.016 |
394 parameters | Δρmax = 0.73 e Å−3 |
0 restraints | Δρmin = −1.24 e Å−3 |
[Rh2(C13H17O5)4(C4H4N2)2] | γ = 94.23 (1)° |
Mr = 1379.07 | V = 1528.9 (3) Å3 |
Triclinic, P1 | Z = 1 |
a = 7.780 (1) Å | Mo Kα radiation |
b = 13.056 (1) Å | µ = 0.62 mm−1 |
c = 15.245 (1) Å | T = 100 K |
α = 97.04 (1)° | 0.10 × 0.05 × 0.04 mm |
β = 93.48 (1)° |
Nonius KappaCCD area-detector diffractometer | 5375 independent reflections |
Absorption correction: numerical (Coppens et al., 1965) | 4778 reflections with I > 2σ(I) |
Tmin = 0.930, Tmax = 0.979 | Rint = 0.090 |
19184 measured reflections |
R[F2 > 2σ(F2)] = 0.034 | 0 restraints |
wR(F2) = 0.087 | H-atom parameters constrained |
S = 1.06 | Δρmax = 0.73 e Å−3 |
5375 reflections | Δρmin = −1.24 e Å−3 |
394 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 | ||
Rh | 0.62337 (3) | 0.562207 (15) | 0.506482 (13) | 0.01212 (9) | |
O11 | 0.7540 (2) | 0.47187 (14) | 0.58494 (12) | 0.0151 (4) | |
O12 | 0.5193 (2) | 0.35691 (14) | 0.57212 (12) | 0.0165 (4) | |
O13 | 1.2036 (2) | 0.26028 (15) | 0.72891 (14) | 0.0223 (5) | |
O14 | 1.0122 (3) | 0.10071 (16) | 0.78177 (13) | 0.0232 (5) | |
O15 | 0.6716 (3) | 0.07488 (16) | 0.75024 (14) | 0.0264 (5) | |
C1 | 0.6747 (3) | 0.3878 (2) | 0.59992 (17) | 0.0155 (6) | |
C11 | 0.7662 (4) | 0.3159 (2) | 0.65183 (17) | 0.0161 (6) | |
C12 | 0.9444 (4) | 0.3309 (2) | 0.67159 (17) | 0.0167 (6) | |
H12 | 1.0082 | 0.3905 | 0.6568 | 0.020* | |
C13 | 1.0275 (4) | 0.2571 (2) | 0.71333 (18) | 0.0186 (6) | |
C14 | 0.9324 (4) | 0.1713 (2) | 0.73789 (19) | 0.0202 (6) | |
C15 | 0.7522 (4) | 0.1588 (2) | 0.71950 (19) | 0.0209 (6) | |
C16 | 0.6707 (4) | 0.2306 (2) | 0.67564 (18) | 0.0192 (6) | |
H16 | 0.5494 | 0.2215 | 0.6618 | 0.023* | |
C131 | 1.2890 (4) | 0.3583 (2) | 0.76962 (19) | 0.0210 (6) | |
H13A | 1.2586 | 0.4135 | 0.7337 | 0.025* | |
H13B | 1.4157 | 0.3545 | 0.7706 | 0.025* | |
C132 | 1.2381 (4) | 0.3857 (3) | 0.8626 (2) | 0.0347 (8) | |
H13C | 1.1138 | 0.3938 | 0.8615 | 0.052* | |
H13D | 1.3021 | 0.4508 | 0.8890 | 0.052* | |
H13E | 1.2653 | 0.3304 | 0.8979 | 0.052* | |
C141 | 1.0324 (4) | 0.0066 (2) | 0.7238 (2) | 0.0239 (6) | |
H14A | 1.1213 | 0.0195 | 0.6817 | 0.029* | |
H14B | 0.9220 | −0.0179 | 0.6893 | 0.029* | |
C142 | 1.0866 (4) | −0.0736 (2) | 0.7807 (2) | 0.0280 (7) | |
H14C | 1.1917 | −0.0466 | 0.8175 | 0.042* | |
H14D | 1.1094 | −0.1366 | 0.7428 | 0.042* | |
H14E | 0.9940 | −0.0897 | 0.8189 | 0.042* | |
C151 | 0.4969 (4) | 0.0423 (3) | 0.7171 (2) | 0.0313 (8) | |
H15A | 0.4281 | 0.1033 | 0.7194 | 0.038* | |
H15B | 0.4452 | −0.0061 | 0.7552 | 0.038* | |
C152 | 0.4898 (5) | −0.0101 (3) | 0.6234 (3) | 0.0421 (9) | |
H15C | 0.5389 | 0.0381 | 0.5854 | 0.063* | |
H15D | 0.3694 | −0.0317 | 0.6026 | 0.063* | |
H15E | 0.5566 | −0.0711 | 0.6212 | 0.063* | |
O21 | 0.5262 (2) | 0.63587 (14) | 0.61581 (12) | 0.0172 (4) | |
O22 | 0.2918 (2) | 0.51995 (14) | 0.60358 (12) | 0.0155 (4) | |
O23 | 0.4852 (2) | 0.84790 (16) | 0.91353 (13) | 0.0243 (5) | |
O24 | 0.1679 (3) | 0.80111 (15) | 0.95913 (12) | 0.0197 (4) | |
O25 | −0.0444 (2) | 0.65010 (15) | 0.86504 (13) | 0.0204 (4) | |
C2 | 0.3848 (3) | 0.5986 (2) | 0.64272 (18) | 0.0158 (6) | |
C21 | 0.3268 (3) | 0.6515 (2) | 0.72595 (18) | 0.0153 (6) | |
C22 | 0.4380 (4) | 0.7276 (2) | 0.77777 (18) | 0.0179 (6) | |
H22 | 0.5481 | 0.7473 | 0.7585 | 0.021* | |
C23 | 0.3865 (4) | 0.7736 (2) | 0.85717 (19) | 0.0184 (6) | |
C24 | 0.2234 (4) | 0.7463 (2) | 0.88483 (18) | 0.0168 (6) | |
C25 | 0.1121 (3) | 0.6708 (2) | 0.83212 (18) | 0.0163 (6) | |
C26 | 0.1637 (3) | 0.6233 (2) | 0.75319 (18) | 0.0163 (6) | |
H26 | 0.0887 | 0.5717 | 0.7176 | 0.020* | |
C231 | 0.6635 (4) | 0.8691 (2) | 0.8960 (2) | 0.0254 (7) | |
H23A | 0.6718 | 0.9053 | 0.8428 | 0.030* | |
H23B | 0.7209 | 0.8039 | 0.8860 | 0.030* | |
C232 | 0.7473 (4) | 0.9373 (3) | 0.9773 (3) | 0.0478 (11) | |
H23C | 0.6945 | 1.0034 | 0.9838 | 0.072* | |
H23D | 0.8712 | 0.9499 | 0.9705 | 0.072* | |
H23E | 0.7303 | 0.9026 | 1.0299 | 0.072* | |
C241 | 0.1590 (4) | 0.7470 (3) | 1.0362 (2) | 0.0300 (7) | |
H24A | 0.0896 | 0.6800 | 1.0198 | 0.036* | |
H24B | 0.0996 | 0.7885 | 1.0821 | 0.036* | |
C242 | 0.3345 (5) | 0.7275 (3) | 1.0739 (2) | 0.0419 (9) | |
H24C | 0.3890 | 0.6805 | 1.0309 | 0.063* | |
H24D | 0.3230 | 0.6961 | 1.1287 | 0.063* | |
H24E | 0.4062 | 0.7932 | 1.0869 | 0.063* | |
C251 | −0.1644 (4) | 0.5724 (2) | 0.8150 (2) | 0.0237 (7) | |
H25A | −0.1064 | 0.5087 | 0.7979 | 0.028* | |
H25B | −0.2109 | 0.5978 | 0.7605 | 0.028* | |
C252 | −0.3074 (4) | 0.5504 (3) | 0.8733 (2) | 0.0277 (7) | |
H25C | −0.2612 | 0.5204 | 0.9248 | 0.042* | |
H25D | −0.3964 | 0.5014 | 0.8399 | 0.042* | |
H25E | −0.3581 | 0.6150 | 0.8933 | 0.042* | |
N31 | 0.8368 (3) | 0.69037 (18) | 0.51780 (15) | 0.0177 (5) | |
N32 | 1.0803 (3) | 0.8604 (2) | 0.52869 (17) | 0.0262 (6) | |
C31 | 0.9997 (4) | 0.6838 (2) | 0.54265 (19) | 0.0216 (6) | |
H31 | 1.0358 | 0.6197 | 0.5573 | 0.026* | |
C33 | 0.9133 (4) | 0.8669 (2) | 0.5037 (2) | 0.0258 (7) | |
H33 | 0.8779 | 0.9313 | 0.4891 | 0.031* | |
C32 | 1.1209 (4) | 0.7690 (2) | 0.5480 (2) | 0.0234 (6) | |
H32 | 1.2375 | 0.7608 | 0.5663 | 0.028* | |
C34 | 0.7922 (4) | 0.7845 (2) | 0.49831 (19) | 0.0219 (6) | |
H34 | 0.6753 | 0.7930 | 0.4808 | 0.026* |
U11 | U22 | U33 | U12 | U13 | U23 | |
Rh | 0.01228 (12) | 0.01076 (12) | 0.01245 (13) | −0.00064 (8) | 0.00041 (8) | −0.00076 (8) |
O11 | 0.0153 (9) | 0.0126 (9) | 0.0168 (10) | −0.0007 (7) | −0.0016 (7) | 0.0018 (7) |
O12 | 0.0141 (9) | 0.0162 (10) | 0.0187 (10) | −0.0016 (8) | −0.0019 (8) | 0.0027 (8) |
O13 | 0.0142 (10) | 0.0163 (10) | 0.0347 (12) | 0.0023 (8) | −0.0041 (8) | −0.0016 (9) |
O14 | 0.0263 (11) | 0.0201 (11) | 0.0225 (11) | 0.0048 (9) | −0.0029 (9) | 0.0000 (9) |
O15 | 0.0224 (11) | 0.0247 (12) | 0.0340 (12) | 0.0016 (9) | 0.0021 (9) | 0.0114 (10) |
C1 | 0.0168 (14) | 0.0165 (14) | 0.0124 (13) | 0.0020 (11) | 0.0031 (10) | −0.0034 (11) |
C11 | 0.0196 (14) | 0.0132 (13) | 0.0141 (13) | 0.0029 (11) | −0.0005 (11) | −0.0038 (11) |
C12 | 0.0199 (14) | 0.0145 (14) | 0.0146 (13) | 0.0005 (11) | −0.0005 (11) | −0.0012 (11) |
C13 | 0.0164 (14) | 0.0183 (14) | 0.0184 (14) | 0.0000 (11) | −0.0033 (11) | −0.0049 (11) |
C14 | 0.0213 (15) | 0.0207 (15) | 0.0181 (14) | 0.0038 (12) | −0.0022 (11) | 0.0009 (12) |
C15 | 0.0237 (15) | 0.0175 (15) | 0.0209 (15) | −0.0017 (12) | 0.0013 (12) | 0.0025 (12) |
C16 | 0.0145 (14) | 0.0224 (15) | 0.0194 (14) | 0.0004 (11) | −0.0014 (11) | −0.0005 (12) |
C131 | 0.0157 (14) | 0.0225 (15) | 0.0228 (15) | −0.0024 (11) | −0.0036 (11) | −0.0003 (12) |
C132 | 0.0233 (16) | 0.049 (2) | 0.0271 (18) | −0.0076 (15) | 0.0000 (13) | −0.0067 (15) |
C141 | 0.0245 (16) | 0.0221 (15) | 0.0247 (16) | 0.0052 (12) | 0.0028 (12) | −0.0013 (12) |
C142 | 0.0311 (17) | 0.0198 (16) | 0.0351 (18) | 0.0058 (13) | 0.0030 (14) | 0.0084 (13) |
C151 | 0.0180 (15) | 0.0276 (17) | 0.050 (2) | −0.0022 (13) | 0.0025 (14) | 0.0132 (15) |
C152 | 0.0310 (19) | 0.034 (2) | 0.058 (2) | −0.0031 (15) | −0.0009 (17) | −0.0016 (18) |
O21 | 0.0174 (10) | 0.0144 (10) | 0.0183 (10) | −0.0031 (8) | 0.0025 (8) | −0.0025 (8) |
O22 | 0.0150 (9) | 0.0139 (9) | 0.0162 (10) | −0.0016 (7) | 0.0002 (7) | −0.0019 (8) |
O23 | 0.0174 (10) | 0.0246 (11) | 0.0253 (11) | −0.0054 (9) | 0.0009 (8) | −0.0139 (9) |
O24 | 0.0257 (11) | 0.0187 (10) | 0.0132 (10) | 0.0023 (8) | 0.0040 (8) | −0.0058 (8) |
O25 | 0.0187 (10) | 0.0195 (10) | 0.0207 (10) | −0.0043 (8) | 0.0058 (8) | −0.0057 (8) |
C2 | 0.0150 (13) | 0.0156 (14) | 0.0167 (14) | 0.0011 (11) | −0.0016 (11) | 0.0034 (11) |
C21 | 0.0174 (14) | 0.0120 (13) | 0.0159 (14) | 0.0007 (11) | 0.0018 (11) | −0.0004 (11) |
C22 | 0.0157 (14) | 0.0180 (14) | 0.0190 (14) | 0.0000 (11) | 0.0012 (11) | −0.0003 (11) |
C23 | 0.0207 (14) | 0.0137 (13) | 0.0185 (14) | 0.0001 (11) | −0.0035 (11) | −0.0033 (11) |
C24 | 0.0195 (14) | 0.0146 (14) | 0.0166 (14) | 0.0043 (11) | 0.0022 (11) | 0.0011 (11) |
C25 | 0.0163 (14) | 0.0146 (13) | 0.0184 (14) | 0.0028 (11) | 0.0016 (11) | 0.0027 (11) |
C26 | 0.0182 (14) | 0.0118 (13) | 0.0177 (14) | −0.0018 (11) | −0.0015 (11) | −0.0002 (11) |
C231 | 0.0178 (15) | 0.0239 (16) | 0.0303 (17) | −0.0047 (12) | 0.0020 (12) | −0.0096 (13) |
C232 | 0.0250 (18) | 0.053 (2) | 0.053 (2) | −0.0105 (17) | 0.0029 (16) | −0.034 (2) |
C241 | 0.0411 (19) | 0.0336 (18) | 0.0154 (15) | 0.0050 (15) | 0.0068 (13) | −0.0006 (13) |
C242 | 0.057 (2) | 0.043 (2) | 0.0271 (19) | 0.0156 (18) | 0.0002 (16) | 0.0055 (16) |
C251 | 0.0191 (15) | 0.0243 (16) | 0.0248 (16) | −0.0040 (12) | 0.0000 (12) | −0.0037 (13) |
C252 | 0.0214 (15) | 0.0279 (17) | 0.0323 (18) | −0.0056 (13) | 0.0047 (13) | 0.0010 (14) |
N31 | 0.0207 (13) | 0.0162 (12) | 0.0144 (12) | −0.0041 (10) | 0.0027 (9) | −0.0026 (9) |
N32 | 0.0233 (13) | 0.0265 (14) | 0.0264 (14) | −0.0048 (11) | 0.0000 (11) | −0.0010 (11) |
C31 | 0.0226 (15) | 0.0219 (15) | 0.0200 (15) | 0.0020 (12) | 0.0009 (12) | 0.0018 (12) |
C33 | 0.0282 (17) | 0.0198 (15) | 0.0281 (17) | −0.0012 (12) | 0.0008 (13) | 0.0010 (13) |
C32 | 0.0191 (15) | 0.0270 (16) | 0.0222 (15) | −0.0029 (12) | −0.0002 (12) | −0.0013 (13) |
C34 | 0.0200 (15) | 0.0214 (15) | 0.0241 (16) | 0.0012 (12) | −0.0012 (12) | 0.0037 (12) |
Rh—O12i | 2.026 (2) | N32—C32 | 1.320 (4) |
Rh—O21 | 2.035 (2) | N32—C33 | 1.344 (4) |
Rh—O22i | 2.049 (2) | C31—C32 | 1.395 (4) |
Rh—O11 | 2.056 (2) | C33—C34 | 1.368 (4) |
Rh—N31 | 2.252 (2) | C12—H12 | 0.9499 |
Rh—Rhi | 2.4037 (4) | C16—H16 | 0.9499 |
O11—C1 | 1.271 (3) | C22—H22 | 0.9501 |
O12—C1 | 1.276 (3) | C26—H26 | 0.9501 |
O12—Rhi | 2.026 (2) | C12—H12 | 0.9499 |
O13—C13 | 1.373 (3) | C16—H16 | 0.9499 |
O13—C131 | 1.448 (3) | C22—H22 | 0.9501 |
O14—C14 | 1.367 (3) | C26—H26 | 0.9501 |
O14—C141 | 1.448 (3) | C31—H31 | 0.9497 |
O15—C15 | 1.369 (4) | C32—H32 | 0.9503 |
O15—C151 | 1.437 (4) | C33—H33 | 0.9513 |
C1—C11 | 1.492 (4) | C34—H34 | 0.9504 |
C11—C16 | 1.391 (4) | C131—H13A | 0.9906 |
C11—C12 | 1.395 (4) | C131—H13B | 0.9899 |
C12—C13 | 1.394 (4) | C132—H13E | 0.9796 |
C13—C14 | 1.399 (4) | C132—H13C | 0.9799 |
C14—C15 | 1.406 (4) | C132—H13D | 0.9807 |
C15—C16 | 1.384 (4) | C141—H14B | 0.9900 |
C131—C132 | 1.503 (4) | C141—H14A | 0.9909 |
C141—C142 | 1.507 (4) | C142—H14E | 0.9803 |
C151—C152 | 1.502 (5) | C142—H14C | 0.9803 |
O21—C2 | 1.281 (3) | C142—H14D | 0.9794 |
O22—C2 | 1.274 (3) | C151—H15A | 0.9901 |
O22—Rhi | 2.049 (2) | C151—H15B | 0.9896 |
O23—C23 | 1.369 (3) | C152—H15C | 0.9789 |
O23—C231 | 1.442 (3) | C152—H15D | 0.9801 |
O24—C24 | 1.374 (3) | C152—H15E | 0.9808 |
O24—C241 | 1.446 (4) | C231—H23A | 0.9905 |
O25—C25 | 1.366 (3) | C231—H23B | 0.9898 |
O25—C251 | 1.437 (3) | C232—H23C | 0.9796 |
C2—C21 | 1.480 (4) | C232—H23D | 0.9797 |
C21—C26 | 1.397 (4) | C232—H23E | 0.9792 |
C21—C22 | 1.399 (4) | C241—H24A | 0.9897 |
C22—C23 | 1.380 (4) | C241—H24B | 0.9900 |
C23—C24 | 1.396 (4) | C242—H24C | 0.9796 |
C24—C25 | 1.401 (4) | C242—H24D | 0.9806 |
C25—C26 | 1.381 (4) | C242—H24E | 0.9801 |
C231—C232 | 1.516 (4) | C251—H25A | 0.9898 |
C241—C242 | 1.501 (5) | C251—H25B | 0.9899 |
C251—C252 | 1.498 (4) | C252—H25C | 0.9803 |
N31—C31 | 1.312 (4) | C252—H25D | 0.9798 |
N31—C34 | 1.364 (4) | C252—H25E | 0.9801 |
O12i—Rh—O21 | 90.31 (8) | C21—C22—H22 | 120.29 |
O12i—Rh—O22i | 89.98 (7) | C21—C26—H26 | 120.17 |
O21—Rh—O22i | 176.08 (7) | C25—C26—H26 | 120.20 |
O12i—Rh—O11 | 175.91 (7) | C32—C31—H31 | 119.32 |
O21—Rh—O11 | 89.93 (8) | N31—C31—H31 | 119.29 |
O22i—Rh—O11 | 89.51 (7) | C31—C32—H32 | 118.59 |
O12i—Rh—N31 | 88.98 (8) | N32—C32—H32 | 118.68 |
O21—Rh—N31 | 88.82 (8) | N32—C33—H33 | 118.71 |
O22i—Rh—N31 | 95.10 (8) | C34—C33—H33 | 118.72 |
O11—Rh—N31 | 95.11 (8) | N31—C34—H34 | 119.53 |
O12i—Rh—Rhi | 86.44 (5) | C33—C34—H34 | 119.54 |
O21—Rh—Rhi | 88.30 (5) | H13A—C131—H13B | 107.94 |
O22i—Rh—Rhi | 87.82 (5) | O13—C131—H13B | 109.31 |
O11—Rh—Rhi | 89.48 (5) | O13—C131—H13A | 109.32 |
N31—Rh—Rhi | 174.57 (6) | C132—C131—H13A | 109.28 |
C1—O11—Rh | 117.2 (2) | C132—C131—H13B | 109.26 |
C1—O12—Rhi | 121.9 (2) | C131—C132—H13C | 109.46 |
C13—O13—C131 | 116.2 (2) | C131—C132—H13E | 109.47 |
C14—O14—C141 | 111.8 (2) | H13C—C132—H13D | 109.51 |
C15—O15—C151 | 118.2 (2) | C131—C132—H13D | 109.44 |
O11—C1—O12 | 125.0 (2) | H13D—C132—H13E | 109.48 |
O11—C1—C11 | 119.7 (2) | H13C—C132—H13E | 109.46 |
O12—C1—C11 | 115.3 (2) | C142—C141—H14B | 110.18 |
C16—C11—C12 | 121.0 (2) | O14—C141—H14A | 110.17 |
C16—C11—C1 | 118.2 (2) | O14—C141—H14B | 110.16 |
C12—C11—C1 | 120.7 (2) | C142—C141—H14A | 110.12 |
C13—C12—C11 | 119.0 (3) | H14A—C141—H14B | 108.36 |
O13—C13—C12 | 123.5 (3) | H14D—C142—H14E | 109.47 |
O13—C13—C14 | 116.1 (2) | C141—C142—H14C | 109.44 |
C12—C13—C14 | 120.3 (3) | C141—C142—H14D | 109.51 |
O14—C14—C13 | 120.7 (2) | C141—C142—H14E | 109.48 |
O14—C14—C15 | 119.5 (3) | H14C—C142—H14D | 109.47 |
C13—C14—C15 | 119.9 (3) | H14C—C142—H14E | 109.46 |
O15—C15—C16 | 125.5 (3) | O15—C151—H15A | 109.37 |
O15—C15—C14 | 114.8 (2) | O15—C151—H15B | 109.43 |
C16—C15—C14 | 119.7 (3) | C152—C151—H15A | 109.36 |
C15—C16—C11 | 120.1 (3) | C152—C151—H15B | 109.36 |
O13—C131—C132 | 111.6 (3) | H15A—C151—H15B | 108.02 |
O14—C141—C142 | 107.8 (2) | C151—C152—H15C | 109.48 |
O15—C151—C152 | 111.2 (3) | C151—C152—H15D | 109.48 |
C2—O21—Rh | 119.4 (2) | C151—C152—H15E | 109.41 |
C2—O22—Rhi | 119.4 (2) | H15C—C152—H15D | 109.57 |
C23—O23—C231 | 118.2 (2) | H15C—C152—H15E | 109.46 |
C24—O24—C241 | 115.9 (2) | H15D—C152—H15E | 109.43 |
C25—O25—C251 | 118.2 (2) | O23—C231—H23A | 110.48 |
O22—C2—O21 | 125.0 (3) | O23—C231—H23B | 110.50 |
O22—C2—C21 | 118.1 (2) | C232—C231—H23A | 110.47 |
O21—C2—C21 | 116.9 (2) | C232—C231—H23B | 110.50 |
C26—C21—C22 | 120.6 (3) | H23A—C231—H23B | 108.71 |
C26—C21—C2 | 119.8 (2) | C231—C232—H23C | 109.42 |
C22—C21—C2 | 119.5 (2) | C231—C232—H23D | 109.38 |
C23—C22—C21 | 119.4 (3) | C231—C232—H23E | 109.44 |
O23—C23—C22 | 124.4 (3) | H23C—C232—H23D | 109.48 |
O23—C23—C24 | 115.2 (2) | H23C—C232—H23E | 109.55 |
C22—C23—C24 | 120.4 (2) | H23D—C232—H23E | 109.55 |
O24—C24—C23 | 119.2 (2) | O24—C241—H24A | 109.21 |
O24—C24—C25 | 120.7 (2) | O24—C241—H24B | 109.11 |
C23—C24—C25 | 119.8 (3) | C242—C241—H24A | 109.14 |
O25—C25—C26 | 124.8 (2) | C242—C241—H24B | 109.19 |
O25—C25—C24 | 115.1 (2) | H24A—C241—H24B | 107.84 |
C26—C25—C24 | 120.1 (3) | C241—C242—H24C | 109.49 |
C25—C26—C21 | 119.6 (2) | C241—C242—H24D | 109.49 |
O23—C231—C232 | 106.2 (2) | C241—C242—H24E | 109.51 |
O24—C241—C242 | 112.2 (3) | H24C—C242—H24D | 109.49 |
O25—C251—C252 | 107.1 (2) | H24C—C242—H24E | 109.50 |
C31—N31—C34 | 116.7 (3) | H24D—C242—H24E | 109.35 |
C31—N31—Rh | 126.4 (2) | O25—C251—H25A | 110.30 |
C34—N31—Rh | 116.9 (2) | O25—C251—H25B | 110.35 |
C32—N32—C33 | 115.7 (3) | C252—C251—H25A | 110.28 |
N31—C31—C32 | 121.4 (3) | C252—C251—H25B | 110.26 |
N32—C33—C34 | 122.5 (3) | H25A—C251—H25B | 108.61 |
N32—C32—C31 | 122.7 (3) | C251—C252—H25C | 109.48 |
N31—C34—C33 | 120.9 (3) | C251—C252—H25D | 109.46 |
C13—C12—H12 | 120.48 | C251—C252—H25E | 109.45 |
C11—C12—H12 | 120.50 | H25C—C252—H25D | 109.46 |
C11—C16—H16 | 120.01 | H25C—C252—H25E | 109.51 |
C15—C16—H16 | 119.90 | H25D—C252—H25E | 109.47 |
C23—C22—H22 | 120.30 | ||
O21—Rh—O11—C1 | 88.95 (18) | C22—C23—C24—O24 | −172.9 (2) |
O22i—Rh—O11—C1 | −87.17 (18) | O23—C23—C24—C25 | −179.9 (2) |
N31—Rh—O11—C1 | 177.75 (18) | C22—C23—C24—C25 | 0.7 (4) |
Rhi—Rh—O11—C1 | 0.65 (18) | C251—O25—C25—C26 | 0.9 (4) |
Rh—O11—C1—O12 | −2.1 (3) | C251—O25—C25—C24 | −179.2 (2) |
Rh—O11—C1—C11 | 176.34 (17) | O24—C24—C25—O25 | −6.2 (4) |
Rhi—O12—C1—O11 | 2.6 (4) | C23—C24—C25—O25 | −179.8 (2) |
Rhi—O12—C1—C11 | −175.87 (16) | O24—C24—C25—C26 | 173.8 (2) |
O11—C1—C11—C16 | 172.8 (2) | C23—C24—C25—C26 | 0.2 (4) |
O12—C1—C11—C16 | −8.6 (4) | O25—C25—C26—C21 | 179.5 (2) |
O11—C1—C11—C12 | −10.7 (4) | C24—C25—C26—C21 | −0.5 (4) |
O12—C1—C11—C12 | 167.9 (2) | C22—C21—C26—C25 | −0.1 (4) |
C16—C11—C12—C13 | 2.0 (4) | C2—C21—C26—C25 | 178.2 (2) |
C1—C11—C12—C13 | −174.4 (2) | C23—O23—C231—C232 | −169.1 (3) |
C131—O13—C13—C12 | 49.0 (4) | C24—O24—C241—C242 | 68.3 (3) |
C131—O13—C13—C14 | −134.1 (3) | C25—O25—C251—C252 | 169.0 (2) |
C11—C12—C13—O13 | 174.4 (2) | O12i—Rh—N31—C31 | −161.4 (2) |
C11—C12—C13—C14 | −2.3 (4) | O21—Rh—N31—C31 | 108.3 (2) |
C141—O14—C14—C13 | −103.7 (3) | O22i—Rh—N31—C31 | −71.5 (2) |
C141—O14—C14—C15 | 78.0 (3) | O11—Rh—N31—C31 | 18.5 (2) |
O13—C13—C14—O14 | 5.5 (4) | O12i—Rh—N31—C34 | 19.7 (2) |
C12—C13—C14—O14 | −177.6 (2) | O21—Rh—N31—C34 | −70.6 (2) |
O13—C13—C14—C15 | −176.2 (2) | O22i—Rh—N31—C34 | 109.6 (2) |
C12—C13—C14—C15 | 0.7 (4) | O11—Rh—N31—C34 | −160.4 (2) |
C151—O15—C15—C16 | 16.3 (4) | C34—N31—C31—C32 | −0.5 (4) |
C151—O15—C15—C14 | −165.6 (3) | Rh—N31—C31—C32 | −179.4 (2) |
O14—C14—C15—O15 | 1.3 (4) | C32—N32—C33—C34 | 0.0 (4) |
C13—C14—C15—O15 | −177.0 (3) | C33—N32—C32—C31 | 0.3 (4) |
O14—C14—C15—C16 | 179.5 (2) | N31—C31—C32—N32 | 0.0 (5) |
C13—C14—C15—C16 | 1.2 (4) | C31—N31—C34—C33 | 0.8 (4) |
O15—C15—C16—C11 | 176.5 (3) | Rh—N31—C34—C33 | 179.8 (2) |
C14—C15—C16—C11 | −1.5 (4) | N32—C33—C34—N31 | −0.5 (5) |
C12—C11—C16—C15 | −0.1 (4) | O13—C131—C132—H13C | −62.48 |
C1—C11—C16—C15 | 176.4 (2) | O13—C131—C132—H13D | 177.49 |
C13—O13—C131—C132 | 66.3 (3) | O13—C131—C132—H13E | 57.50 |
C14—O14—C141—C142 | −168.5 (2) | H13A—C131—C132—H13C | 58.58 |
C15—O15—C151—C152 | 73.6 (4) | H13A—C131—C132—H13D | −61.45 |
O12i—Rh—O21—C2 | 87.68 (19) | H13A—C131—C132—H13E | 178.56 |
O11—Rh—O21—C2 | −88.23 (19) | H13B—C131—C132—H13C | 176.48 |
N31—Rh—O21—C2 | 176.66 (19) | H13B—C131—C132—H13D | 56.45 |
Rhi—Rh—O21—C2 | 1.25 (19) | H13B—C131—C132—H13E | −63.54 |
Rhi—O22—C2—O21 | 4.4 (4) | O14—C141—C142—H14C | −55.90 |
Rhi—O22—C2—C21 | −175.31 (17) | O14—C141—C142—H14D | −175.90 |
Rh—O21—C2—O22 | −3.8 (4) | O14—C141—C142—H14E | 64.07 |
Rh—O21—C2—C21 | 175.96 (17) | H14A—C141—C142—H14C | 64.35 |
O22—C2—C21—C26 | −8.3 (4) | H14A—C141—C142—H14D | −55.65 |
O21—C2—C21—C26 | 172.0 (2) | H14A—C141—C142—H14E | −175.68 |
O22—C2—C21—C22 | 170.1 (2) | H14B—C141—C142—H14C | −176.17 |
O21—C2—C21—C22 | −9.7 (4) | H14B—C141—C142—H14D | 63.83 |
C26—C21—C22—C23 | 1.1 (4) | H14B—C141—C142—H14E | −56.20 |
C2—C21—C22—C23 | −177.3 (2) | O15—C151—C152—H15C | −60.08 |
C231—O23—C23—C22 | −9.5 (4) | O15—C151—C152—H15D | −179.79 |
C231—O23—C23—C24 | 171.1 (3) | O15—C151—C152—H15E | 59.87 |
C21—C22—C23—O23 | 179.3 (3) | H15A—C151—C152—H15C | 60.83 |
C21—C22—C23—C24 | −1.3 (4) | H15A—C151—C152—H15D | −59.30 |
C241—O24—C24—C23 | −109.1 (3) | H15B—C151—C152—H15C | 178.94 |
C241—O24—C24—C25 | 77.3 (3) | H15B—C151—C152—H15D | 58.81 |
O23—C23—C24—O24 | 6.5 (4) | H15B—C151—C152—H15E | −61.11 |
Symmetry code: (i) −x+1, −y+1, −z+1. |
Experimental details
Crystal data | |
Chemical formula | [Rh2(C13H17O5)4(C4H4N2)2] |
Mr | 1379.07 |
Crystal system, space group | Triclinic, P1 |
Temperature (K) | 100 |
a, b, c (Å) | 7.780 (1), 13.056 (1), 15.245 (1) |
α, β, γ (°) | 97.04 (1), 93.48 (1), 94.23 (1) |
V (Å3) | 1528.9 (3) |
Z | 1 |
Radiation type | Mo Kα |
µ (mm−1) | 0.62 |
Crystal size (mm) | 0.10 × 0.05 × 0.04 |
Data collection | |
Diffractometer | Nonius KappaCCD area-detector diffractometer |
Absorption correction | Numerical (Coppens et al., 1965) |
Tmin, Tmax | 0.930, 0.979 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 19184, 5375, 4778 |
Rint | 0.090 |
(sin θ/λ)max (Å−1) | 0.595 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.034, 0.087, 1.06 |
No. of reflections | 5375 |
No. of parameters | 394 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.73, −1.24 |
Computer programs: COLLECT (Nonius, 1997), HKL SCALEPACK (Otwinowski & Minor 1997), HKL DENZO (Otwinowski & Minor 1997) and SCALEPACK, SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), ORTEPII (Johnson, 1976), SHELXL97.
Rh—O12i | 2.026 (2) | Rh—O11 | 2.056 (2) |
Rh—O21 | 2.035 (2) | Rh—N31 | 2.252 (2) |
Rh—O22i | 2.049 (2) | Rh—Rhi | 2.4037 (4) |
O12i—Rh—O21 | 90.31 (8) | O22i—Rh—N31 | 95.10 (8) |
O12i—Rh—O22i | 89.98 (7) | O11—Rh—N31 | 95.11 (8) |
O21—Rh—O22i | 176.08 (7) | O12i—Rh—Rhi | 86.44 (5) |
O12i—Rh—O11 | 175.91 (7) | O21—Rh—Rhi | 88.30 (5) |
O21—Rh—O11 | 89.93 (8) | O22i—Rh—Rhi | 87.82 (5) |
O22i—Rh—O11 | 89.51 (7) | O11—Rh—Rhi | 89.48 (5) |
O12i—Rh—N31 | 88.98 (8) | N31—Rh—Rhi | 174.57 (6) |
O21—Rh—N31 | 88.82 (8) |
Symmetry code: (i) −x+1, −y+1, −z+1. |
Lantern-type dirhodium carboxylates of the general formula [Rh2II,II(O2CR)4L2] (L are axial ligands) have been the subject of numerous investigations focusing on their catalytic properties, antitumour activity, molecular and electronic structure, spectroscopic features and chemical reactivity (Norman et al., 1979; Christoph & Koh, 1979; Boyar & Robinson, 1983; Cotton & Walton, 1992; Kitamura et al., 2000). Moreover, their use as building blocks in the synthesis of advanced materials has received increasing attention (Marchon et al., 1992; Barberá et al., 1992; Bonnar-Law et al., 2000; Rusjan et al., 2002). We have recently found that coordination polymers formed from dirhodium subunits linked by axial pyrazine ligands have interesting liquid-crystalline properties if the equatorial ligands are bulky carboxylates. We have suggested supramolecular models to explain the structural features of the mesophases formed (Rusjan et al., 2002).
Although molecular structures have been reported for many rhodium bisadducts, they mainly involve aliphatic equatorial carboxylates (Christoph & Koh, 1979; Kitamura et al., 2000). As far as we know, the only published structures of dirhodium tetrabenzoate N-heterocyclic bisadducts are those of [Rh2(O2CPh)4(C5H5N)2] (Mehmet & Tocher, 1991) and [Rh2(TTB)4(C5H5N)2], where TTB is 2,4,6-tri-p-tolylbenzoate (Callot et al., 1989). Pyrazine bisadducts of rhodium tetracarboxylates are rare, and only one aliphatic pyrazine derivative corresponding to [Rh2(O2CCH3)4{2-(1-pyrrolyle)pyrazine}2] has been published (Viossat et al., 1993). In order to understand the liquid crystalline properties better, the structure of the title compound, (I), has been determined. \sch
Complex (I) is sited at a crystallographic inversion centre. Each Rh atom is in a slightly distorted octahedral environment (Fig. 1, Table 1). The values of the Rh—Rh, Rh—N31 and mean Rh—O bonds are typical for this kind of compound, and are very close to those found for [Rh2(O2CPh)4(C5H5N)2] [2.402 (1), 2.247 (4) and 2.041 (3) Å, respectively; Mehmet & Tocher, 1991] and [Rh2(TTB)4(C5H5N)2] [2.374 (1), 2.25 (4) and 2.050 (8) Å, respectively; Callot et al., 1989]. The distances and angles in (I) are also in the normal range for analogous amine bisadducts (Cotton & Walton, 1992; Bonnar-Law et al., 2000; Kitamura et al., 2000).
The phenyl rings of the equatorial ligands are tilted ca 10° with respect to the planes of their carboxylate groups. Moreover, the ethoxy substituents have different conformations in the two independent benzoate groups. In one of them, the 3- and 5-alkoxy chains are in the plane of the phenyl ring, in a zigzag trans conformation [C23—O23—C231—C232 and C25—O25—C251—C252 dihedral angles of 169.1 (3) and 169.0 (2)°, respectively], while the 4-alkoxy chain adopts a gauche conformation [C24—O24—C241—C242 dihedral angle of 68.3 (3)°]. In the other benzoate ligand, the 3- and 5-alkoxy chains adopt gauche conformations [C13—O13—C131—C132 and C15—O15—C151—C152 dihedral angles of 66.3 (3) and 73.6 (4)°, respectively], pointing towards opposite sides of the phenyl ring plane, while the 4-substituent has a trans conformation [C14—O14—C141—C142 dihedral angle of 168.5 (2)°].
The pyrazine rings have a torsion angle of ca 18.5° around the Rh—N31 bond with respect to the plane of the nearer carboxylate group, and they are non-coplanar with the Rh—Rh axis [Rh—Rh—N31 and Rh—N31—N32 angles of 174.57 (6) and 175.3 (1)°, respectively], as has already been observed for other related compounds (Mehmet & Tocher, 1991; Cotton et al., 1992; Miyasaka et al., 2001) but not seen for Viossat's pyrazine derivative bisadduct (Viossat et al., 1993). No comparisons can be made with [Rh2(TTB)4(C5H5N)2] compound, where the axial pyridines are highly dirsordered (Callot et al., 1989). The deviation from linearity of the Rh—Rh—N31 angle is comparable to that found in other systems exhibiting hydrogen bonds (Kitamura et al., 2000) or H-π interactions (Bonnar-Law et al., 2000). However, no evidence of such interactions has been found in (I). Nevertheless, it supports the hypothesis suggested for the mesophase of the long-chain polymeric analogues, where non-linear Rh—Pz—Rh arrangements were proposed. The explanation of these features still remains open.