Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270110040989/gd3364sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S0108270110040989/gd3364Isup2.hkl |
CCDC reference: 804113
Copper(II) oxydiacetate hemihydrate (0.01 mol) and nicotinamide (0.02 mol) were added to a methanol–water solution (3:1 v/v, 100 ml). The mixture was heated at 333 K with stirring for 1 h, filtered, and the solution left to stand at ambient temperature. After a few days, large blue crystals of (I) were separated. Analysis: found C 33.1, H 4.1, N 7.7, Cu 17.1%; C20H30Cu2N4O17 requires: C 33.1, H 4.1, N, 7.7, Cu 17.5%. EDAX analysis on a Philips 515 microscope (Philips Export BV, Eindhoven, The Netherlands) equipped with an EDAX PV9100 probe (EDAX International Inc., Prairie View, Illinois, USA) showed that Cu was the only metallic element present.
The solvent water molecules appear disordered around inversion centres: molecule O2W with a fully occupied O atom but disordered H atoms, and the remaining one, O3W, split into two halves (at bumping distance from each other), the occupancy of which refined freely to a value slightly larger than one half [0.58 (4)]. The parameter was finally fixed at 0.50, as an `antibumping' condition limiting the simultaneous presence of both otherwise colliding centrosymmetrically related images. This fact, in turn, in conjunction with the requirements posed by a feasible hydrogen-bonding scheme, forced the occupancy of the remaining disordered H atoms H2W and H3W to be also 0.50. All the H atoms attached to O (even those in the problematic solvent water molecules) could be located in a difference Fourier map. They were further idealized, with O—H = 0.85 Å and H···H = 1.35 Å, and finally allowed to ride. Those attached to C and N were placed in calculated positions, with C—H = 0.93, C—H2 = 0.97 and N—H2 = 0.86 Å, and allowed to ride. Displacement parameters were taken as Uiso(H) = 1.2Ueq(carrier).
Data collection: CrysAlis PRO (Oxford Diffraction, 2009); cell refinement: CrysAlis PRO (Oxford Diffraction, 2009); data reduction: CrysAlis PRO (Oxford Diffraction, 2009); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008) and PLATON (Spek, 2009).
[Cu(C4H4O5)(C6H6N2O)(H2O)]·1.5H2O | F(000) = 744 |
Mr = 725.58 | Dx = 1.704 Mg m−3 |
Monoclinic, P21/n | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2yn | Cell parameters from 4378 reflections |
a = 7.1545 (2) Å | θ = 4.1–26.5° |
b = 11.0251 (3) Å | µ = 1.59 mm−1 |
c = 18.1342 (5) Å | T = 294 K |
β = 98.349 (3)° | Prism, blue |
V = 1415.25 (7) Å3 | 0.35 × 0.30 × 0.20 mm |
Z = 2 |
Oxford Gemini CCD S Ultra diffractometer | 3194 independent reflections |
Radiation source: fine-focus sealed tube | 2408 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.024 |
ω scans, thick slices | θmax = 28.7°, θmin = 3.7° |
Absorption correction: multi-scan (CrysAlis PRO; Oxford Diffraction (2009) | h = −9→9 |
Tmin = 0.54, Tmax = 0.73 | k = −11→14 |
6237 measured reflections | l = −22→17 |
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)] = 0.034 | H-atom parameters constrained |
wR(F2) = 0.089 | w = 1/[σ2(Fo2) + (0.0583P)2] where P = (Fo2 + 2Fc2)/3 |
S = 0.92 | (Δ/σ)max = 0.002 |
3194 reflections | Δρmax = 0.53 e Å−3 |
200 parameters | Δρmin = −0.72 e Å−3 |
0 restraints | Extinction correction: SHELXL97 (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
Primary atom site location: structure-invariant direct methods | Extinction coefficient: 0.0237 (14) |
[Cu(C4H4O5)(C6H6N2O)(H2O)]·1.5H2O | V = 1415.25 (7) Å3 |
Mr = 725.58 | Z = 2 |
Monoclinic, P21/n | Mo Kα radiation |
a = 7.1545 (2) Å | µ = 1.59 mm−1 |
b = 11.0251 (3) Å | T = 294 K |
c = 18.1342 (5) Å | 0.35 × 0.30 × 0.20 mm |
β = 98.349 (3)° |
Oxford Gemini CCD S Ultra diffractometer | 3194 independent reflections |
Absorption correction: multi-scan (CrysAlis PRO; Oxford Diffraction (2009) | 2408 reflections with I > 2σ(I) |
Tmin = 0.54, Tmax = 0.73 | Rint = 0.024 |
6237 measured reflections |
R[F2 > 2σ(F2)] = 0.034 | 0 restraints |
wR(F2) = 0.089 | H-atom parameters constrained |
S = 0.92 | Δρmax = 0.53 e Å−3 |
3194 reflections | Δρmin = −0.72 e Å−3 |
200 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. |
x | y | z | Uiso*/Ueq | Occ. (<1) | |
Cu1 | 0.57189 (4) | 0.41942 (2) | 0.702055 (14) | 0.02732 (12) | |
O11 | 0.5439 (2) | 0.24693 (14) | 0.72064 (9) | 0.0322 (4) | |
O21 | 0.4599 (2) | 0.11531 (15) | 0.80235 (9) | 0.0347 (4) | |
O31 | 0.4263 (3) | 0.43028 (13) | 0.78506 (9) | 0.0375 (4) | |
O41 | 0.4606 (2) | 0.74490 (14) | 0.77485 (9) | 0.0368 (4) | |
O51 | 0.5334 (2) | 0.59508 (13) | 0.70201 (8) | 0.0302 (4) | |
C11 | 0.4826 (3) | 0.21904 (19) | 0.78064 (12) | 0.0263 (5) | |
C21 | 0.4361 (4) | 0.32380 (18) | 0.82998 (13) | 0.0332 (6) | |
H21A | 0.3162 | 0.3096 | 0.8476 | 0.040* | |
H21B | 0.5335 | 0.3322 | 0.8728 | 0.040* | |
C31 | 0.4372 (4) | 0.5458 (2) | 0.81963 (13) | 0.0340 (6) | |
H31A | 0.5367 | 0.5468 | 0.8621 | 0.041* | |
H31B | 0.3186 | 0.5656 | 0.8367 | 0.041* | |
C41 | 0.4801 (3) | 0.63717 (19) | 0.76087 (12) | 0.0250 (5) | |
N12 | 0.6560 (3) | 0.40308 (15) | 0.60395 (10) | 0.0241 (4) | |
N22 | 0.8352 (3) | 0.59573 (17) | 0.38737 (10) | 0.0316 (5) | |
H22A | 0.8495 | 0.5277 | 0.3656 | 0.038* | |
H22B | 0.8640 | 0.6574 | 0.3622 | 0.038* | |
O12 | 0.8004 (3) | 0.70192 (15) | 0.48996 (10) | 0.0422 (5) | |
C52 | 0.6547 (3) | 0.2935 (2) | 0.57148 (12) | 0.0310 (5) | |
H52 | 0.6212 | 0.2261 | 0.5975 | 0.037* | |
C42 | 0.7010 (4) | 0.2773 (2) | 0.50141 (13) | 0.0385 (6) | |
H42 | 0.6994 | 0.2002 | 0.4806 | 0.046* | |
C32 | 0.7501 (4) | 0.3768 (2) | 0.46201 (12) | 0.0313 (5) | |
H32 | 0.7807 | 0.3678 | 0.4142 | 0.038* | |
C22 | 0.7531 (3) | 0.49040 (18) | 0.49505 (11) | 0.0218 (5) | |
C12 | 0.7056 (3) | 0.49948 (19) | 0.56597 (12) | 0.0224 (5) | |
H12 | 0.7081 | 0.5755 | 0.5883 | 0.027* | |
C62 | 0.8004 (3) | 0.60460 (19) | 0.45681 (12) | 0.0241 (5) | |
O1W | 0.8561 (3) | 0.43842 (14) | 0.77497 (10) | 0.0406 (4) | |
H1WA | 0.9189 | 0.3747 | 0.7688 | 0.049* | |
H1WB | 0.9081 | 0.4993 | 0.7575 | 0.049* | |
O2W | 0.8214 (3) | 0.95283 (18) | 0.49377 (12) | 0.0639 (6) | |
H2WA | 0.8312 | 0.8770 | 0.4869 | 0.077* | |
H2WB | 0.7132 | 0.9760 | 0.5023 | 0.077* | 0.50 |
H2WC | 0.9294 | 0.9864 | 0.4988 | 0.077* | 0.50 |
O3W | 0.5383 (7) | 0.9948 (4) | 0.5740 (2) | 0.0686 (13) | 0.50 |
H3WA | 0.5125 | 0.9625 | 0.6139 | 0.082* | 0.50 |
H3WB | 0.6322 | 0.9590 | 0.5599 | 0.082* | 0.50 |
U11 | U22 | U33 | U12 | U13 | U23 | |
Cu1 | 0.0433 (2) | 0.01744 (16) | 0.02512 (17) | 0.00069 (12) | 0.01808 (12) | 0.00083 (10) |
O11 | 0.0489 (11) | 0.0202 (8) | 0.0317 (9) | 0.0004 (8) | 0.0204 (7) | 0.0018 (6) |
O21 | 0.0480 (11) | 0.0204 (8) | 0.0386 (10) | −0.0008 (7) | 0.0168 (8) | 0.0085 (7) |
O31 | 0.0656 (13) | 0.0199 (8) | 0.0335 (9) | −0.0001 (8) | 0.0288 (8) | 0.0011 (6) |
O41 | 0.0514 (11) | 0.0207 (8) | 0.0425 (10) | 0.0012 (8) | 0.0210 (8) | −0.0049 (7) |
O51 | 0.0437 (11) | 0.0213 (8) | 0.0290 (9) | 0.0020 (7) | 0.0166 (7) | 0.0006 (6) |
C11 | 0.0268 (12) | 0.0234 (11) | 0.0293 (12) | 0.0006 (10) | 0.0065 (9) | 0.0025 (9) |
C21 | 0.0536 (16) | 0.0218 (11) | 0.0272 (12) | −0.0012 (11) | 0.0168 (10) | 0.0052 (9) |
C31 | 0.0527 (17) | 0.0227 (11) | 0.0298 (12) | 0.0006 (11) | 0.0170 (11) | −0.0034 (9) |
C41 | 0.0268 (12) | 0.0204 (11) | 0.0287 (12) | −0.0008 (10) | 0.0074 (9) | −0.0020 (9) |
N12 | 0.0270 (10) | 0.0221 (9) | 0.0248 (9) | 0.0022 (8) | 0.0094 (7) | 0.0002 (7) |
N22 | 0.0440 (13) | 0.0265 (10) | 0.0274 (10) | 0.0000 (9) | 0.0153 (8) | 0.0060 (8) |
O12 | 0.0631 (13) | 0.0249 (8) | 0.0435 (10) | −0.0039 (9) | 0.0241 (9) | −0.0023 (7) |
C52 | 0.0442 (15) | 0.0202 (10) | 0.0316 (12) | 0.0005 (11) | 0.0160 (10) | 0.0018 (9) |
C42 | 0.0627 (18) | 0.0204 (11) | 0.0367 (14) | −0.0038 (12) | 0.0220 (12) | −0.0064 (9) |
C32 | 0.0451 (15) | 0.0277 (11) | 0.0241 (12) | −0.0009 (11) | 0.0154 (10) | −0.0031 (9) |
C22 | 0.0215 (11) | 0.0218 (11) | 0.0231 (11) | 0.0021 (9) | 0.0066 (8) | 0.0008 (8) |
C12 | 0.0227 (11) | 0.0197 (10) | 0.0256 (11) | −0.0008 (9) | 0.0062 (9) | −0.0011 (8) |
C62 | 0.0221 (11) | 0.0229 (10) | 0.0285 (11) | 0.0011 (9) | 0.0075 (8) | 0.0019 (8) |
O1W | 0.0480 (11) | 0.0280 (9) | 0.0457 (10) | 0.0017 (8) | 0.0062 (8) | 0.0010 (7) |
O2W | 0.0784 (16) | 0.0384 (11) | 0.0778 (16) | −0.0099 (11) | 0.0217 (12) | −0.0073 (10) |
O3W | 0.085 (3) | 0.071 (3) | 0.051 (3) | 0.025 (3) | 0.012 (2) | 0.005 (2) |
Cu1—O11 | 1.9467 (15) | N22—H22A | 0.8600 |
Cu1—O31 | 1.9547 (16) | N22—H22B | 0.8600 |
Cu1—O51 | 1.9561 (15) | O12—C62 | 1.230 (3) |
Cu1—N12 | 1.9675 (18) | C52—C42 | 1.370 (3) |
Cu1—O1W | 2.2684 (19) | C52—H52 | 0.9300 |
O11—C11 | 1.268 (3) | C42—C32 | 1.382 (3) |
O21—C11 | 1.228 (3) | C42—H42 | 0.9300 |
O31—C31 | 1.417 (3) | C32—C22 | 1.387 (3) |
O31—C21 | 1.425 (2) | C32—H32 | 0.9300 |
O41—C41 | 1.227 (3) | C22—C12 | 1.381 (3) |
O51—C41 | 1.272 (3) | C22—C62 | 1.499 (3) |
C11—C21 | 1.527 (3) | C12—H12 | 0.9300 |
C21—H21A | 0.9700 | O1W—H1WA | 0.8501 |
C21—H21B | 0.9700 | O1W—H1WB | 0.8500 |
C31—C41 | 1.529 (3) | O2W—H2WA | 0.8501 |
C31—H31A | 0.9700 | O2W—H2WB | 0.8499 |
C31—H31B | 0.9700 | O2W—H2WC | 0.8500 |
N12—C12 | 1.342 (3) | O3W—H3WA | 0.8500 |
N12—C52 | 1.343 (3) | O3W—H3WB | 0.8500 |
N22—C62 | 1.322 (3) | ||
O11—Cu1—O31 | 81.19 (6) | O51—C41—C31 | 117.34 (19) |
O11—Cu1—O51 | 161.66 (7) | C12—N12—C52 | 118.22 (19) |
O31—Cu1—O51 | 81.31 (6) | C12—N12—Cu1 | 122.00 (14) |
O11—Cu1—N12 | 96.88 (7) | C52—N12—Cu1 | 119.67 (14) |
O31—Cu1—N12 | 165.74 (8) | C62—N22—H22A | 123.5 |
O51—Cu1—N12 | 98.73 (7) | C62—N22—H22B | 122.6 |
O11—Cu1—O1W | 95.47 (6) | H22A—N22—H22B | 113.1 |
O31—Cu1—O1W | 94.49 (7) | N12—C52—C42 | 122.4 (2) |
O51—Cu1—O1W | 91.32 (6) | N12—C52—H52 | 118.8 |
N12—Cu1—O1W | 99.76 (7) | C42—C52—H52 | 118.8 |
C11—O11—Cu1 | 116.25 (14) | C52—C42—C32 | 119.3 (2) |
C31—O31—C21 | 119.53 (18) | C52—C42—H42 | 120.3 |
C31—O31—Cu1 | 113.22 (13) | C32—C42—H42 | 120.3 |
C21—O31—Cu1 | 113.72 (13) | C42—C32—C22 | 118.8 (2) |
C41—O51—Cu1 | 114.85 (14) | C42—C32—H32 | 120.6 |
O21—C11—O11 | 125.4 (2) | C22—C32—H32 | 120.6 |
O21—C11—C21 | 117.8 (2) | C12—C22—C32 | 118.51 (19) |
O11—C11—C21 | 116.82 (18) | C12—C22—C62 | 118.19 (18) |
O31—C21—C11 | 106.55 (18) | C32—C22—C62 | 123.27 (19) |
O31—C21—H21A | 110.4 | N12—C12—C22 | 122.67 (19) |
C11—C21—H21A | 110.4 | N12—C12—H12 | 118.7 |
O31—C21—H21B | 110.4 | C22—C12—H12 | 118.7 |
C11—C21—H21B | 110.4 | O12—C62—N22 | 122.9 (2) |
H21A—C21—H21B | 108.6 | O12—C62—C22 | 119.4 (2) |
O31—C31—C41 | 106.71 (18) | N22—C62—C22 | 117.69 (19) |
O31—C31—H31A | 110.4 | Cu1—O1W—H1WA | 107.0 |
C41—C31—H31A | 110.4 | Cu1—O1W—H1WB | 105.0 |
O31—C31—H31B | 110.4 | H1WA—O1W—H1WB | 109.6 |
C41—C31—H31B | 110.4 | H2WA—O2W—H2WB | 114.8 |
H31A—C31—H31B | 108.6 | H2WA—O2W—H2WC | 110.5 |
O41—C41—O51 | 125.7 (2) | H2WB—O2W—H2WC | 133.4 |
O41—C41—C31 | 117.0 (2) | H3WA—O3W—H3WB | 109.8 |
O31—Cu1—O11—C11 | −11.93 (16) | Cu1—O51—C41—C31 | −5.2 (3) |
O51—Cu1—O11—C11 | −29.5 (3) | O31—C31—C41—O41 | 166.7 (2) |
N12—Cu1—O11—C11 | −177.67 (16) | O31—C31—C41—O51 | −13.5 (3) |
O1W—Cu1—O11—C11 | 81.78 (17) | O11—Cu1—N12—C12 | −176.77 (17) |
O11—Cu1—O31—C31 | 161.77 (17) | O31—Cu1—N12—C12 | 102.0 (3) |
O51—Cu1—O31—C31 | −23.73 (17) | O51—Cu1—N12—C12 | 12.88 (18) |
N12—Cu1—O31—C31 | −115.0 (3) | O1W—Cu1—N12—C12 | −79.99 (17) |
O1W—Cu1—O31—C31 | 66.92 (17) | O11—Cu1—N12—C52 | 6.94 (18) |
O11—Cu1—O31—C21 | 21.02 (16) | O31—Cu1—N12—C52 | −74.3 (3) |
O51—Cu1—O31—C21 | −164.48 (17) | O51—Cu1—N12—C52 | −163.41 (17) |
N12—Cu1—O31—C21 | 104.2 (3) | O1W—Cu1—N12—C52 | 103.72 (18) |
O1W—Cu1—O31—C21 | −73.83 (16) | C12—N12—C52—C42 | −0.3 (4) |
O11—Cu1—O51—C41 | 33.3 (3) | Cu1—N12—C52—C42 | 176.1 (2) |
O31—Cu1—O51—C41 | 15.78 (16) | N12—C52—C42—C32 | −0.3 (4) |
N12—Cu1—O51—C41 | −178.65 (16) | C52—C42—C32—C22 | 0.7 (4) |
O1W—Cu1—O51—C41 | −78.57 (17) | C42—C32—C22—C12 | −0.4 (3) |
Cu1—O11—C11—O21 | −178.35 (18) | C42—C32—C22—C62 | −178.7 (2) |
Cu1—O11—C11—C21 | 0.8 (3) | C52—N12—C12—C22 | 0.7 (3) |
C31—O31—C21—C11 | −162.6 (2) | Cu1—N12—C12—C22 | −175.68 (15) |
Cu1—O31—C21—C11 | −24.6 (2) | C32—C22—C12—N12 | −0.3 (3) |
O21—C11—C21—O31 | −165.2 (2) | C62—C22—C12—N12 | 178.08 (19) |
O11—C11—C21—O31 | 15.5 (3) | C12—C22—C62—O12 | 1.9 (3) |
C21—O31—C31—C41 | 164.0 (2) | C32—C22—C62—O12 | −179.8 (2) |
Cu1—O31—C31—C41 | 25.7 (2) | C12—C22—C62—N22 | −176.3 (2) |
Cu1—O51—C41—O41 | 174.55 (19) | C32—C22—C62—N22 | 2.0 (3) |
D—H···A | D—H | H···A | D···A | D—H···A |
C12—H12···O12 | 0.93 | 2.43 | 2.761 (3) | 101 |
C12—H12···O51 | 0.93 | 2.57 | 3.099 (3) | 116 |
C52—H52···O11 | 0.93 | 2.39 | 2.972 (3) | 121 |
N22—H22A···O21i | 0.86 | 2.17 | 2.998 (2) | 163 |
N22—H22B···O41ii | 0.86 | 2.11 | 2.930 (2) | 158 |
O1W—H1WA···O41iii | 0.85 | 1.90 | 2.726 (2) | 163 |
O1W—H1WB···O21iv | 0.85 | 2.00 | 2.835 (2) | 167 |
O2W—H2WA···O12 | 0.85 | 1.94 | 2.771 (3) | 164 |
O2W—H2WB···O3W | 0.85 | 1.94 | 2.700 (5) | 148 |
O2W—H2WB···O3Wv | 0.85 | 2.13 | 2.747 (5) | 129 |
O2W—H2WC···O2Wvi | 0.85 | 1.89 | 2.738 (5) | 175 |
O3W—H3WA···O1Wiv | 0.85 | 2.11 | 2.804 (4) | 138 |
O3W—H3WB···O2W | 0.85 | 1.94 | 2.700 (5) | 149 |
Symmetry codes: (i) x+1/2, −y+1/2, z−1/2; (ii) x+1/2, −y+3/2, z−1/2; (iii) −x+3/2, y−1/2, −z+3/2; (iv) −x+3/2, y+1/2, −z+3/2; (v) −x+1, −y+2, −z+1; (vi) −x+2, −y+2, −z+1. |
Experimental details
Crystal data | |
Chemical formula | [Cu(C4H4O5)(C6H6N2O)(H2O)]·1.5H2O |
Mr | 725.58 |
Crystal system, space group | Monoclinic, P21/n |
Temperature (K) | 294 |
a, b, c (Å) | 7.1545 (2), 11.0251 (3), 18.1342 (5) |
β (°) | 98.349 (3) |
V (Å3) | 1415.25 (7) |
Z | 2 |
Radiation type | Mo Kα |
µ (mm−1) | 1.59 |
Crystal size (mm) | 0.35 × 0.30 × 0.20 |
Data collection | |
Diffractometer | Oxford Gemini CCD S Ultra diffractometer |
Absorption correction | Multi-scan (CrysAlis PRO; Oxford Diffraction (2009) |
Tmin, Tmax | 0.54, 0.73 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 6237, 3194, 2408 |
Rint | 0.024 |
(sin θ/λ)max (Å−1) | 0.676 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.034, 0.089, 0.92 |
No. of reflections | 3194 |
No. of parameters | 200 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.53, −0.72 |
Computer programs: CrysAlis PRO (Oxford Diffraction, 2009), SHELXS97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008) and PLATON (Spek, 2009).
Cu1—O11 | 1.9467 (15) | Cu1—N12 | 1.9675 (18) |
Cu1—O31 | 1.9547 (16) | Cu1—O1W | 2.2684 (19) |
Cu1—O51 | 1.9561 (15) |
D—H···A | D—H | H···A | D···A | D—H···A |
C12—H12···O12 | 0.93 | 2.43 | 2.761 (3) | 101 |
C12—H12···O51 | 0.93 | 2.57 | 3.099 (3) | 116 |
C52—H52···O11 | 0.93 | 2.39 | 2.972 (3) | 121 |
N22—H22A···O21i | 0.86 | 2.17 | 2.998 (2) | 162.6 |
N22—H22B···O41ii | 0.86 | 2.11 | 2.930 (2) | 158.4 |
O1W—H1WA···O41iii | 0.85 | 1.90 | 2.726 (2) | 163.1 |
O1W—H1WB···O21iv | 0.85 | 2.00 | 2.835 (2) | 166.6 |
O2W—H2WA···O12 | 0.85 | 1.94 | 2.771 (3) | 163.8 |
O2W—H2WB···O3W | 0.85 | 1.94 | 2.700 (5) | 147.7 |
O2W—H2WB···O3Wv | 0.85 | 2.13 | 2.747 (5) | 129.3 |
O2W—H2WC···O2Wvi | 0.85 | 1.89 | 2.738 (5) | 174.5 |
O3W—H3WA···O1Wiv | 0.85 | 2.11 | 2.804 (4) | 138.0 |
O3W—H3WB···O2W | 0.85 | 1.94 | 2.700 (5) | 148.9 |
Symmetry codes: (i) x+1/2, −y+1/2, z−1/2; (ii) x+1/2, −y+3/2, z−1/2; (iii) −x+3/2, y−1/2, −z+3/2; (iv) −x+3/2, y+1/2, −z+3/2; (v) −x+1, −y+2, −z+1; (vi) −x+2, −y+2, −z+1. |
The coordination flexibility of Cu atoms, combined with the electronic and steric diversity of selected organic ligands, still leads to novel architectures and topologies in the field of copper(II) carboxylates (Perec et al., 2010; Sartoris et al., 2010, etc.). We recently reported a new ternary copper compound, [Cu(C4H4O5)(C6H6N2O)(H2O)2], (II), isolated from the CuII–oxydiacetate (ODA)–pyridine-3-carboxamide (p3ca) system, with one (κ3O,O'O'') ODA anion, one (κ1-N) monodentate p3ca ligand and two aqua molecules bonded to the central CuII ion (Perec & Baggio, 2009). In this compound, the two organic ligands define the basal plane of an octahedral arrangement around the CuII cation, while two water ligands occupy the apical sites (see scheme). By slightly changing the reaction conditions (methanol:water 3:1 instead of 1:1), blue crystals of the title compound formulated as [Cu(C4H4O5)(C6H6N2O)(H2O)].1.5H2O, (I), were obtained, a pentacoordinated CuII complex, the crystal and molecular structure of which we report here.
Fig. 1 shows that the ODA and p3ca coordination to CuII in (I) is similar to that in (II), a planar arrangement spanning a tight range of Cu—O/N distances [Cu—O = 1.9467 (15)–1.9561 (15) and 1.964 (2)–1.989 (2) Å, and Cu—N = 1.9675 (18) and 1.989 (2) Å for (I) and (II), respectively]. The main structural difference resides in the apical water ligands: only one in (I), at a Cu1—O1W distance of 2.2684 (18) Å, to complete a square-pyramidal polyhedron, but two in (II), with Cu—Owater distances of 2.359 (3) and 2.483 (2) Å, to generate octahedral geometry.
In compound (I) the ODA ligand presents a slight out-of-plane puckering at its central atom O31 [0.27 (1) Å out of the mean plane containing the remaining atoms, mean deviation from the least-squares plane < 0.02 (1) Å]. A similar effect, but disordered on both sides of the plane, was observed in (II). Also, as in (II), the terminal carboxylates in (I) present partial delocalization, with the coordinated O atoms showing a distinct lengthening in their C—O bonds with respect to the non-coordinated ones [O11—C11 = 1.268 (3) and O21—C11 = 1.228 (3), and O41—C41 = 1.227 (3) and O51—C41 = 1.272 (3) Å].
As a difference from (II), the p3ca unit in (I) is nearly planar, with a dihedral angle of 2.7 (1)° between the pyridyl and amide planes, smaller than its value in (II) [10.1 (1)°]. The free rotation of the amide planar group appears to be hindered by the intramolecular C12—H12···O12 hydrogen bond linking both subunits (Table 2, first entry, and Fig. 2), which gives rise to an S(5) motif (Bernstein et al., 1995) labelled A in Fig. 1. There are two further weak non-conventional intramolecular C—H interactions restraining the free rotation of the pyridyl ring around the Cu—N11 bond, which generate two more S(5) motifs, labelled B1 and B2 in Fig. 1, which in turn link this group to the coordinated O atoms in ODA (O11 and O51) (Table 2, entries 2 and 3).
In addition to these weak C—H···O interactions influencing the molecular geometry of (I), there are a number of strong hydrogen bonds having water and amine H atoms on the donor side and carboxylate and amide O atoms on the acceptor side, which define the main aspects of the crystal structure. Through these, each monomer interacts with six different symmetry-related analogues, similar to what was found for (II). However, the two packing schemes are quite different. Fig. 2 shows a view of (I), parallel to (101) and displaying the planar array determined by just one specific type of hydrogen bond, those involving the amide N—H group as donors and the uncoordinated ODA O atoms (O21 and O41) as acceptors (Table 2, entries 4 and 5). These bonds, and the resulting large R44(32) loops which they generate (in Fig. 2, those involving amides N22, N22i and N22ii), define almost planar two-dimensional arrays [mean square deviation from the least-squares plane = 0.12 (1) Å, with apical ligands excluded from the calculation]. A characteristic of these structures is that they have all their Cu—Owater apical bonds pointing in the same direction (downwards in the case represented in Fig. 2).
Since the inversion centres in the structure of (I) are located at (x, y, z), with x, y and z either 0 or 1/2, we can arbitrarily define two possible families, those with x + z = 1/2, 3/2 etc., denoted type a, and a complementary set with x + z = 0, 1 etc., denoted type b. These two families have different effects when operating on the above-mentioned planes: type a centres generate structures which oppose apical Cu—Owater vectors in related planes, so that water molecules corresponding to monomers in one plane in fact end up appearing very near the neighbouring plane, at hydrogen-bonding distances, and vice versa. This is shown in Figs. 1 and 2, which show the connectivity resulting from (O—H)water···OODA hydrogen bonds (Table 2, entries 6 and 7). It is relevant for the discussion below to note that these hydrogen bonds are, as for those previously discussed, almost parallel to the planar structure they help to build. The bonds give rise to tight R42(8) in-plane loops (labelled D in Fig. 2) and large R22(12) out-of-plane loops (labelled C1 and C2 in Fig. 1), which help to clamp the two planar structures into a thick bilayer with a separation d1 = 3.18 (1) Å. On the other hand, inversion centres of type b relate the basal planes of the Cu coordination polyhedra in a back-to-back fashion (Fig. 3) with only weak interactions between them, basically the hydrogen bonds involving the disordered solvent water molecules O2W and O3W (see encircled zones in Fig. 2 and related discussion below), at an interplanar distance d2 = 3.10 (1) Å.
This similarity (d1 ~ d2) in interplanar separation at a graphitic distance strongly suggests a dominant π–π interaction, which is compatible with the fact that all the strong hydrogen bonds in the structure are in-plane and thus contribute mainly to the lateral coherence between monomers rather than to the interaction between planes. The solvent water molecules correspond to one fully occupied (O2W) and one half-occupied (O3W); the latter is disordered around a type a inversion centre, thus providing for a 1 local symmetry in an `average' sense, i.e. when one half is present, the remaining one must be absent and vice versa. Molecule O2W is also placed near a type a inversion centre, generating a symmetric image with which it could only coexist through some kind of disorder of the H atoms involved (in order to give short H···H contacts). In spite of the disordered nature of the hydrate system, the difference map allowed the detection of three `H like' peaks around O2W and two in the neighbourhood of O3W, giving on average the model displayed in Fig. 4(a), and which could be consistently interpreted as explained in Figs. 4(b) and 4(c). These models present two mutually exclusive but complementary motifs: both of them are present at random in the structure with a 50% probability, and when added together they make up the `average' structure represented in Fig. 4(a) and described by the centrosymmetric space group P21/n. The interaction takes the form of a column, climbing along [100] and linking alternate planes, anchored at the aldehyde O atom (O12) and the aqua ligand (O1W).
In spite of the structural differences between (I) and (II), the X-ray powder diffraction diagrams showed that both compounds end up in a similar crystalline dehydration product when the thermally driven dehydration process is conducted up to a maximum of 450 K. Mass-loss calculations [found/expected for (I): 12.6/12.39%; found/expected for (II): 10.4/10.19%] suggest a formula for the common dehydration product of [Cu(ODA)(p3ca)].
A final word of caution: although there is clear synthetic and analytical evidence for the composition of (I), nevertheless significantly lower R indices were obtained when the structure was refined as an Ni complex rather than as a Cu complex. However, despite the R-factor indications, the Hirshfeld tests implemented in PLATON CheckCIF (Spek, 2009) generated a significant number of alerts for the Ni refinement but none for the Cu version, indicating an incorrect assignment of atom type in the case of Ni. We can propose no simple explanation for this apparent paradox.