Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S010827010501053X/fa1124sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S010827010501053X/fa1124Isup2.hkl |
CCDC reference: 275495
Squaric acid (0.57 g, 5 mmol) dissolved in water (25 ml) was neutralized with NaOH (0.40 g, 10 mmol) and was added to a hot solution of CuCl2·H2O (0.77 g, 5 mmol) dissolved in water (50 ml). The mixture was stirred at 333 K for 12 h and then cooled to room temperature. The yellow crystals which formed were filtered off, washed with water and alcohol, and dried in vacuo. A solution of neocuproine (0.435 g, 2 mmol) in methanol (50 ml) was added dropwise with stirring to a suspension of CuSq·2H2O (0.21 g, 1 mmol) in water (50 ml). In highly basic media, the CuII was reduced to CuI and the squarate dianion was protonated. The bright-red solution was refluxed for about 2 h and then cooled to room temperature. A few days later, well formed red crystals of (I) were selected for X-ray studies.
H atoms attached to C atoms were placed at calculated positions (C—H = 0.93 and 0.96 Å) and were allowed to ride on their parent atom [Uiso(H) = 1.2Ueq(C)]. The remaining H atom was located in a difference map. At this stage, the maximum difference density of 1.48 e Å−3 (the ratio of maximum/minimum residual density is 5.62) indicated the presence of a possible atom site. A check for the solvent-accessible volume using PLATON (Spek, 2003) showed a total potential solvent area volume of 40.6 Å3. Attempts to refine this peak as a water O atom (O5) resulted in a partial occupancy of 0.5. H atoms attached to O5 were not located.
Data collection: X-AREA (Stoe & Cie, 2002); cell refinement: X-AREA; data reduction: X-RED32 (Stoe & Cie, 2002); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEPIII (Farrugia, 1997); software used to prepare material for publication: WinGX (Farrugia, 1999).
[Cu(C14H12N2)2]C4HO4·0.5H2O | F(000) = 1240 |
Mr = 602.11 | Dx = 1.455 Mg m−3 |
Monoclinic, P21/c | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2ybc | Cell parameters from 5048 reflections |
a = 15.9664 (10) Å | θ = 1.6–28.0° |
b = 13.7530 (12) Å | µ = 0.84 mm−1 |
c = 13.5082 (11) Å | T = 297 K |
β = 112.343 (6)° | Plate, red |
V = 2743.5 (4) Å3 | 0.31 × 0.25 × 0.19 mm |
Z = 4 |
Stoe IPDS 2 diffractometer | 4828 independent reflections |
Radiation source: fine-focus sealed tube | 2280 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.131 |
Detector resolution: 6.67 pixels mm-1 | θmax = 25.0°, θmin = 2.0° |
ω scans | h = −18→18 |
Absorption correction: integration (X-RED32; Stoe & Cie, 2002) | k = −16→16 |
Tmin = 0.728, Tmax = 0.924 | l = −16→16 |
22893 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)] = 0.041 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.075 | H atoms treated by a mixture of independent and constrained refinement |
S = 0.81 | w = 1/[σ2(Fo2) + (0.011P)2] where P = (Fo2 + 2Fc2)/3 |
4828 reflections | (Δ/σ)max < 0.001 |
387 parameters | Δρmax = 0.17 e Å−3 |
3 restraints | Δρmin = −0.29 e Å−3 |
[Cu(C14H12N2)2]C4HO4·0.5H2O | V = 2743.5 (4) Å3 |
Mr = 602.11 | Z = 4 |
Monoclinic, P21/c | Mo Kα radiation |
a = 15.9664 (10) Å | µ = 0.84 mm−1 |
b = 13.7530 (12) Å | T = 297 K |
c = 13.5082 (11) Å | 0.31 × 0.25 × 0.19 mm |
β = 112.343 (6)° |
Stoe IPDS 2 diffractometer | 4828 independent reflections |
Absorption correction: integration (X-RED32; Stoe & Cie, 2002) | 2280 reflections with I > 2σ(I) |
Tmin = 0.728, Tmax = 0.924 | Rint = 0.131 |
22893 measured reflections |
R[F2 > 2σ(F2)] = 0.041 | 3 restraints |
wR(F2) = 0.075 | H atoms treated by a mixture of independent and constrained refinement |
S = 0.81 | Δρmax = 0.17 e Å−3 |
4828 reflections | Δρmin = −0.29 e Å−3 |
387 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 | Occ. (<1) | |
O5 | 0.1793 (5) | 0.1355 (7) | 0.2107 (7) | 0.182 (3) | 0.50 |
H4 | 0.488 (3) | 0.424 (3) | 0.401 (4) | 0.112 (18)* | |
C1 | 0.2538 (3) | 0.5834 (3) | −0.2005 (3) | 0.0741 (12) | |
C2 | 0.3024 (3) | 0.5780 (3) | −0.2676 (3) | 0.0833 (13) | |
H2 | 0.2721 | 0.5660 | −0.3404 | 0.100* | |
C3 | 0.3925 (3) | 0.5901 (3) | −0.2273 (4) | 0.0792 (14) | |
H3 | 0.4243 | 0.5857 | −0.2722 | 0.095* | |
C4 | 0.4389 (3) | 0.6092 (3) | −0.1185 (3) | 0.0591 (10) | |
C5 | 0.5344 (3) | 0.6207 (3) | −0.0684 (4) | 0.0809 (13) | |
H5 | 0.5695 | 0.6162 | −0.1096 | 0.097* | |
C6 | 0.5742 (3) | 0.6375 (3) | 0.0349 (4) | 0.0800 (13) | |
H6 | 0.6367 | 0.6453 | 0.0651 | 0.096* | |
C7 | 0.5236 (2) | 0.6440 (3) | 0.1017 (3) | 0.0623 (10) | |
C8 | 0.5619 (3) | 0.6601 (3) | 0.2116 (4) | 0.0842 (13) | |
H8 | 0.6241 | 0.6688 | 0.2453 | 0.101* | |
C9 | 0.5095 (3) | 0.6630 (3) | 0.2694 (3) | 0.0794 (13) | |
H9 | 0.5357 | 0.6735 | 0.3429 | 0.095* | |
C10 | 0.4149 (3) | 0.6503 (2) | 0.2192 (3) | 0.0622 (10) | |
C11 | 0.4294 (2) | 0.6329 (2) | 0.0562 (3) | 0.0484 (8) | |
C12 | 0.3855 (2) | 0.6149 (2) | −0.0561 (3) | 0.0499 (9) | |
C13 | 0.3550 (3) | 0.6508 (3) | 0.2815 (3) | 0.0877 (14) | |
H13A | 0.3075 | 0.6976 | 0.2513 | 0.132* | |
H13B | 0.3900 | 0.6676 | 0.3546 | 0.132* | |
H13C | 0.3290 | 0.5874 | 0.2787 | 0.132* | |
C14 | 0.1528 (3) | 0.5716 (4) | −0.2432 (3) | 0.1223 (19) | |
H14A | 0.1361 | 0.5334 | −0.1940 | 0.183* | |
H14B | 0.1329 | 0.5394 | −0.3113 | 0.183* | |
H14C | 0.1247 | 0.6344 | −0.2515 | 0.183* | |
C15 | 0.1725 (2) | 0.4575 (3) | 0.1147 (3) | 0.0574 (10) | |
C16 | 0.1168 (2) | 0.4215 (3) | 0.1654 (3) | 0.0674 (11) | |
H16 | 0.1256 | 0.3589 | 0.1935 | 0.081* | |
C17 | 0.0502 (2) | 0.4784 (3) | 0.1733 (3) | 0.0703 (12) | |
H17 | 0.0136 | 0.4547 | 0.2075 | 0.084* | |
C18 | 0.0360 (2) | 0.5722 (3) | 0.1308 (3) | 0.0584 (10) | |
C19 | −0.0337 (2) | 0.6366 (3) | 0.1339 (3) | 0.0724 (12) | |
H19 | −0.0716 | 0.6164 | 0.1678 | 0.087* | |
C20 | −0.0455 (2) | 0.7246 (3) | 0.0896 (3) | 0.0743 (12) | |
H20 | −0.0913 | 0.7646 | 0.0928 | 0.089* | |
C21 | 0.0116 (2) | 0.7578 (3) | 0.0372 (3) | 0.0619 (10) | |
C22 | 0.0023 (3) | 0.8488 (3) | −0.0127 (3) | 0.0777 (12) | |
H22 | −0.0448 | 0.8900 | −0.0157 | 0.093* | |
C23 | 0.0619 (3) | 0.8765 (3) | −0.0566 (3) | 0.0799 (11) | |
H23 | 0.0554 | 0.9367 | −0.0902 | 0.096* | |
C24 | 0.1335 (3) | 0.8150 (3) | −0.0518 (3) | 0.0685 (11) | |
C25 | 0.0828 (2) | 0.6984 (3) | 0.0373 (3) | 0.0546 (9) | |
C26 | 0.0939 (2) | 0.6032 (3) | 0.0822 (3) | 0.0525 (10) | |
C27 | 0.2010 (3) | 0.8441 (3) | −0.0989 (3) | 0.0935 (15) | |
H27A | 0.2612 | 0.8375 | −0.0458 | 0.140* | |
H27B | 0.1907 | 0.9105 | −0.1224 | 0.140* | |
H27C | 0.1944 | 0.8028 | −0.1588 | 0.140* | |
C28 | 0.2472 (2) | 0.3977 (3) | 0.1052 (3) | 0.0760 (12) | |
H28A | 0.2503 | 0.4086 | 0.0364 | 0.114* | |
H28B | 0.2358 | 0.3301 | 0.1125 | 0.114* | |
H28C | 0.3037 | 0.4160 | 0.1604 | 0.114* | |
N1 | 0.29475 (18) | 0.6027 (2) | −0.0963 (2) | 0.0525 (8) | |
N2 | 0.37526 (17) | 0.6379 (2) | 0.1142 (2) | 0.0513 (7) | |
N3 | 0.16179 (17) | 0.5471 (2) | 0.0747 (2) | 0.0538 (8) | |
N4 | 0.14412 (17) | 0.7278 (2) | −0.0053 (2) | 0.0594 (8) | |
Cu1 | 0.24149 (3) | 0.62293 (4) | 0.01577 (4) | 0.06700 (17) | |
C29 | 0.2925 (3) | 0.3467 (3) | 0.4041 (3) | 0.0786 (13) | |
C30 | 0.2772 (3) | 0.4146 (3) | 0.4816 (3) | 0.0779 (13) | |
C31 | 0.3652 (3) | 0.4624 (3) | 0.4954 (3) | 0.0668 (11) | |
C32 | 0.3762 (3) | 0.3958 (3) | 0.4218 (3) | 0.0663 (11) | |
O1 | 0.25035 (19) | 0.2772 (2) | 0.3497 (3) | 0.0956 (9) | |
O2 | 0.2180 (2) | 0.4259 (2) | 0.5159 (3) | 0.1176 (13) | |
O3 | 0.4091 (2) | 0.5326 (2) | 0.5493 (2) | 0.0825 (9) | |
O4 | 0.4382 (2) | 0.3831 (2) | 0.3818 (2) | 0.0955 (10) |
U11 | U22 | U33 | U12 | U13 | U23 | |
O5 | 0.160 (7) | 0.202 (9) | 0.184 (8) | −0.027 (6) | 0.065 (7) | −0.062 (8) |
C1 | 0.074 (3) | 0.096 (3) | 0.059 (3) | −0.016 (2) | 0.033 (2) | −0.003 (2) |
C2 | 0.106 (4) | 0.095 (3) | 0.058 (3) | −0.013 (3) | 0.042 (3) | −0.012 (2) |
C3 | 0.102 (4) | 0.073 (3) | 0.092 (4) | −0.005 (3) | 0.070 (3) | −0.008 (3) |
C4 | 0.067 (3) | 0.045 (2) | 0.083 (3) | −0.002 (2) | 0.049 (3) | 0.000 (2) |
C5 | 0.073 (3) | 0.065 (3) | 0.132 (4) | 0.001 (3) | 0.070 (3) | −0.005 (3) |
C6 | 0.045 (2) | 0.067 (3) | 0.135 (4) | 0.000 (2) | 0.041 (3) | −0.001 (3) |
C7 | 0.051 (2) | 0.050 (3) | 0.081 (3) | 0.0029 (19) | 0.019 (2) | 0.001 (2) |
C8 | 0.053 (3) | 0.066 (3) | 0.109 (4) | −0.001 (2) | 0.004 (3) | −0.003 (3) |
C9 | 0.081 (3) | 0.071 (3) | 0.060 (3) | 0.000 (2) | −0.003 (3) | 0.003 (2) |
C10 | 0.082 (3) | 0.049 (3) | 0.053 (3) | 0.003 (2) | 0.022 (2) | 0.002 (2) |
C11 | 0.049 (2) | 0.037 (2) | 0.063 (2) | 0.0042 (18) | 0.0251 (19) | 0.002 (2) |
C12 | 0.055 (2) | 0.039 (2) | 0.065 (2) | −0.001 (2) | 0.034 (2) | 0.000 (2) |
C13 | 0.123 (4) | 0.094 (4) | 0.054 (2) | −0.008 (3) | 0.042 (3) | −0.005 (2) |
C14 | 0.083 (4) | 0.208 (6) | 0.062 (3) | −0.032 (4) | 0.012 (3) | −0.007 (4) |
C15 | 0.039 (2) | 0.073 (3) | 0.058 (2) | 0.005 (2) | 0.0167 (19) | 0.003 (2) |
C16 | 0.054 (2) | 0.077 (3) | 0.073 (3) | −0.005 (2) | 0.027 (2) | 0.009 (2) |
C17 | 0.051 (2) | 0.099 (3) | 0.069 (3) | −0.015 (2) | 0.033 (2) | −0.002 (3) |
C18 | 0.047 (2) | 0.075 (3) | 0.059 (2) | −0.005 (2) | 0.026 (2) | −0.005 (2) |
C19 | 0.052 (2) | 0.098 (3) | 0.083 (3) | −0.004 (3) | 0.043 (2) | −0.014 (3) |
C20 | 0.057 (3) | 0.088 (3) | 0.086 (3) | 0.009 (2) | 0.036 (2) | −0.015 (3) |
C21 | 0.057 (2) | 0.069 (3) | 0.060 (2) | 0.005 (2) | 0.022 (2) | −0.015 (2) |
C22 | 0.069 (3) | 0.081 (4) | 0.080 (3) | 0.018 (2) | 0.025 (2) | −0.010 (3) |
C23 | 0.097 (3) | 0.061 (3) | 0.082 (3) | 0.016 (3) | 0.033 (3) | 0.010 (3) |
C24 | 0.068 (3) | 0.073 (3) | 0.063 (3) | 0.000 (2) | 0.023 (2) | −0.001 (2) |
C25 | 0.043 (2) | 0.068 (3) | 0.052 (2) | 0.002 (2) | 0.0162 (19) | −0.004 (2) |
C26 | 0.040 (2) | 0.073 (3) | 0.048 (2) | −0.0022 (19) | 0.0206 (19) | −0.004 (2) |
C27 | 0.112 (4) | 0.082 (3) | 0.105 (3) | 0.000 (2) | 0.062 (3) | 0.025 (3) |
C28 | 0.059 (2) | 0.078 (3) | 0.096 (3) | 0.015 (2) | 0.035 (2) | 0.015 (3) |
N1 | 0.0447 (18) | 0.069 (2) | 0.0458 (18) | −0.0046 (16) | 0.0196 (15) | 0.0003 (17) |
N2 | 0.0551 (17) | 0.0532 (19) | 0.0490 (17) | 0.0008 (15) | 0.0238 (15) | 0.0027 (16) |
N3 | 0.0440 (18) | 0.065 (2) | 0.055 (2) | 0.0053 (16) | 0.0211 (16) | 0.0012 (17) |
N4 | 0.055 (2) | 0.072 (2) | 0.0557 (19) | −0.0028 (17) | 0.0264 (16) | 0.0032 (18) |
Cu1 | 0.0510 (3) | 0.0924 (4) | 0.0689 (3) | 0.0038 (3) | 0.0355 (2) | 0.0085 (3) |
C29 | 0.076 (3) | 0.060 (3) | 0.078 (3) | 0.004 (3) | 0.006 (3) | 0.007 (3) |
C30 | 0.084 (4) | 0.074 (3) | 0.076 (3) | −0.005 (2) | 0.031 (3) | 0.003 (3) |
C31 | 0.081 (3) | 0.066 (3) | 0.061 (3) | 0.005 (2) | 0.036 (3) | 0.006 (2) |
C32 | 0.068 (3) | 0.067 (3) | 0.062 (3) | 0.008 (2) | 0.023 (2) | 0.001 (2) |
O1 | 0.077 (2) | 0.080 (2) | 0.109 (2) | 0.0023 (17) | 0.0113 (18) | −0.011 (2) |
O2 | 0.112 (3) | 0.128 (3) | 0.143 (3) | −0.031 (2) | 0.083 (3) | −0.028 (2) |
O3 | 0.099 (2) | 0.084 (2) | 0.079 (2) | −0.0213 (18) | 0.0508 (19) | −0.0257 (18) |
O4 | 0.085 (2) | 0.099 (2) | 0.113 (3) | −0.013 (2) | 0.051 (2) | −0.045 (2) |
C1—N1 | 1.334 (4) | C18—C26 | 1.390 (4) |
C1—C2 | 1.403 (4) | C18—C19 | 1.435 (5) |
C1—C14 | 1.501 (5) | C19—C20 | 1.331 (5) |
C2—C3 | 1.340 (5) | C19—H19 | 0.9300 |
C2—H2 | 0.9300 | C20—C21 | 1.425 (5) |
C3—C4 | 1.396 (5) | C20—H20 | 0.9300 |
C3—H3 | 0.9300 | C21—C25 | 1.399 (4) |
C4—C12 | 1.411 (4) | C21—C22 | 1.402 (5) |
C4—C5 | 1.422 (5) | C22—C23 | 1.354 (5) |
C5—C6 | 1.316 (5) | C22—H22 | 0.9300 |
C5—H5 | 0.9300 | C23—C24 | 1.404 (5) |
C6—C7 | 1.424 (5) | C23—H23 | 0.9300 |
C6—H6 | 0.9300 | C24—N4 | 1.335 (4) |
C7—C8 | 1.392 (5) | C24—C27 | 1.500 (4) |
C7—C11 | 1.400 (4) | C25—N4 | 1.372 (4) |
C8—C9 | 1.345 (5) | C25—C26 | 1.425 (5) |
C8—H8 | 0.9300 | C26—N3 | 1.366 (4) |
C9—C10 | 1.412 (5) | C27—H27A | 0.9600 |
C9—H9 | 0.9300 | C27—H27B | 0.9600 |
C10—N2 | 1.326 (4) | C27—H27C | 0.9600 |
C10—C13 | 1.495 (4) | C28—H28A | 0.9600 |
C11—N2 | 1.370 (3) | C28—H28B | 0.9600 |
C11—C12 | 1.431 (5) | C28—H28C | 0.9600 |
C12—N1 | 1.351 (4) | N1—Cu1 | 2.017 (2) |
C13—H13A | 0.9600 | N2—Cu1 | 2.053 (3) |
C13—H13B | 0.9600 | N3—Cu1 | 2.028 (3) |
C13—H13C | 0.9600 | N4—Cu1 | 2.059 (3) |
C14—H14A | 0.9600 | C29—O1 | 1.237 (4) |
C14—H14B | 0.9600 | C29—C32 | 1.434 (5) |
C14—H14C | 0.9600 | C29—C30 | 1.490 (6) |
C15—N3 | 1.331 (4) | C30—O2 | 1.211 (4) |
C15—C16 | 1.401 (4) | C30—C31 | 1.498 (5) |
C15—C28 | 1.495 (4) | C31—O3 | 1.251 (4) |
C16—C17 | 1.358 (5) | C31—C32 | 1.411 (5) |
C16—H16 | 0.9300 | C32—O4 | 1.308 (4) |
C17—C18 | 1.395 (5) | O4—H4 | 0.93 (4) |
C17—H17 | 0.9300 | ||
N1—C1—C2 | 121.5 (4) | C19—C20—H20 | 119.8 |
N1—C1—C14 | 116.8 (3) | C21—C20—H20 | 119.8 |
C2—C1—C14 | 121.6 (4) | C25—C21—C22 | 117.3 (3) |
C3—C2—C1 | 120.2 (4) | C25—C21—C20 | 119.0 (4) |
C3—C2—H2 | 119.9 | C22—C21—C20 | 123.7 (4) |
C1—C2—H2 | 119.9 | C23—C22—C21 | 119.9 (4) |
C2—C3—C4 | 120.7 (3) | C23—C22—H22 | 120.0 |
C2—C3—H3 | 119.7 | C21—C22—H22 | 120.0 |
C4—C3—H3 | 119.7 | C22—C23—C24 | 120.4 (4) |
C3—C4—C12 | 116.1 (4) | C22—C23—H23 | 119.8 |
C3—C4—C5 | 124.5 (4) | C24—C23—H23 | 119.8 |
C12—C4—C5 | 119.4 (4) | N4—C24—C23 | 121.3 (3) |
C6—C5—C4 | 121.5 (4) | N4—C24—C27 | 117.1 (3) |
C6—C5—H5 | 119.2 | C23—C24—C27 | 121.6 (4) |
C4—C5—H5 | 119.2 | N4—C25—C21 | 122.5 (4) |
C5—C6—C7 | 121.4 (4) | N4—C25—C26 | 117.1 (3) |
C5—C6—H6 | 119.3 | C21—C25—C26 | 120.4 (3) |
C7—C6—H6 | 119.3 | N3—C26—C18 | 123.4 (4) |
C8—C7—C11 | 116.6 (3) | N3—C26—C25 | 117.5 (3) |
C8—C7—C6 | 124.1 (4) | C18—C26—C25 | 119.1 (3) |
C11—C7—C6 | 119.3 (4) | C24—C27—H27A | 109.5 |
C9—C8—C7 | 120.4 (4) | C24—C27—H27B | 109.5 |
C9—C8—H8 | 119.8 | H27A—C27—H27B | 109.5 |
C7—C8—H8 | 119.8 | C24—C27—H27C | 109.5 |
C8—C9—C10 | 120.4 (4) | H27A—C27—H27C | 109.5 |
C8—C9—H9 | 119.8 | H27B—C27—H27C | 109.5 |
C10—C9—H9 | 119.8 | C15—C28—H28A | 109.5 |
N2—C10—C9 | 121.2 (3) | C15—C28—H28B | 109.5 |
N2—C10—C13 | 117.1 (3) | H28A—C28—H28B | 109.5 |
C9—C10—C13 | 121.7 (4) | C15—C28—H28C | 109.5 |
N2—C11—C7 | 123.4 (3) | H28A—C28—H28C | 109.5 |
N2—C11—C12 | 117.0 (3) | H28B—C28—H28C | 109.5 |
C7—C11—C12 | 119.7 (3) | C1—N1—C12 | 118.0 (3) |
N1—C12—C4 | 123.6 (3) | C1—N1—Cu1 | 129.9 (2) |
N1—C12—C11 | 117.7 (3) | C12—N1—Cu1 | 112.0 (2) |
C4—C12—C11 | 118.7 (3) | C10—N2—C11 | 118.0 (3) |
C10—C13—H13A | 109.5 | C10—N2—Cu1 | 131.4 (2) |
C10—C13—H13B | 109.5 | C11—N2—Cu1 | 110.6 (2) |
H13A—C13—H13B | 109.5 | C15—N3—C26 | 118.4 (3) |
C10—C13—H13C | 109.5 | C15—N3—Cu1 | 129.3 (2) |
H13A—C13—H13C | 109.5 | C26—N3—Cu1 | 111.8 (2) |
H13B—C13—H13C | 109.5 | C24—N4—C25 | 118.6 (3) |
C1—C14—H14A | 109.5 | C24—N4—Cu1 | 130.4 (2) |
C1—C14—H14B | 109.5 | C25—N4—Cu1 | 111.0 (2) |
H14A—C14—H14B | 109.5 | N1—Cu1—N3 | 136.87 (12) |
C1—C14—H14C | 109.5 | N1—Cu1—N2 | 82.42 (11) |
H14A—C14—H14C | 109.5 | N3—Cu1—N2 | 116.84 (11) |
H14B—C14—H14C | 109.5 | N1—Cu1—N4 | 120.29 (11) |
N3—C15—C16 | 121.2 (3) | N3—Cu1—N4 | 82.02 (12) |
N3—C15—C28 | 117.2 (3) | N2—Cu1—N4 | 124.33 (11) |
C16—C15—C28 | 121.6 (4) | O1—C29—C32 | 136.5 (4) |
C17—C16—C15 | 119.8 (4) | O1—C29—C30 | 134.7 (4) |
C17—C16—H16 | 120.1 | C32—C29—C30 | 88.8 (3) |
C15—C16—H16 | 120.1 | O2—C30—C29 | 135.2 (4) |
C16—C17—C18 | 120.6 (3) | O2—C30—C31 | 136.7 (4) |
C16—C17—H17 | 119.7 | C29—C30—C31 | 88.1 (3) |
C18—C17—H17 | 119.7 | O3—C31—C32 | 135.9 (3) |
C26—C18—C17 | 116.5 (3) | O3—C31—C30 | 134.7 (3) |
C26—C18—C19 | 119.1 (4) | C32—C31—C30 | 89.4 (3) |
C17—C18—C19 | 124.4 (3) | O4—C32—C31 | 134.0 (4) |
C20—C19—C18 | 121.8 (3) | O4—C32—C29 | 132.2 (4) |
C20—C19—H19 | 119.1 | C31—C32—C29 | 93.8 (3) |
C18—C19—H19 | 119.1 | C32—O4—H4 | 120 (3) |
C19—C20—C21 | 120.5 (4) | ||
N1—C1—C2—C3 | 1.5 (6) | C13—C10—N2—C11 | −177.1 (3) |
C14—C1—C2—C3 | 179.2 (4) | C9—C10—N2—Cu1 | −177.3 (2) |
C1—C2—C3—C4 | −0.7 (6) | C13—C10—N2—Cu1 | 2.3 (5) |
C2—C3—C4—C12 | −0.1 (6) | C7—C11—N2—C10 | −2.6 (5) |
C2—C3—C4—C5 | 178.4 (4) | C12—C11—N2—C10 | 177.1 (3) |
C3—C4—C5—C6 | −179.2 (4) | C7—C11—N2—Cu1 | 177.8 (3) |
C12—C4—C5—C6 | −0.7 (6) | C12—C11—N2—Cu1 | −2.4 (4) |
C4—C5—C6—C7 | 0.7 (7) | C16—C15—N3—C26 | −1.2 (5) |
C5—C6—C7—C8 | 178.9 (5) | C28—C15—N3—C26 | 179.9 (3) |
C5—C6—C7—C11 | −0.4 (6) | C16—C15—N3—Cu1 | 171.1 (3) |
C11—C7—C8—C9 | 0.9 (6) | C28—C15—N3—Cu1 | −7.8 (5) |
C6—C7—C8—C9 | −178.4 (3) | C18—C26—N3—C15 | 0.9 (5) |
C7—C8—C9—C10 | −0.3 (6) | C25—C26—N3—C15 | −179.0 (3) |
C8—C9—C10—N2 | −1.9 (6) | C18—C26—N3—Cu1 | −172.7 (3) |
C8—C9—C10—C13 | 178.5 (3) | C25—C26—N3—Cu1 | 7.3 (4) |
C8—C7—C11—N2 | 0.6 (5) | C23—C24—N4—C25 | 0.6 (5) |
C6—C7—C11—N2 | 179.9 (3) | C27—C24—N4—C25 | −179.1 (3) |
C8—C7—C11—C12 | −179.1 (3) | C23—C24—N4—Cu1 | −179.3 (3) |
C6—C7—C11—C12 | 0.2 (5) | C27—C24—N4—Cu1 | 1.0 (5) |
C3—C4—C12—N1 | 0.2 (5) | C21—C25—N4—C24 | −2.4 (5) |
C5—C4—C12—N1 | −178.4 (4) | C26—C25—N4—C24 | 177.4 (3) |
C3—C4—C12—C11 | 179.1 (3) | C21—C25—N4—Cu1 | 177.5 (3) |
C5—C4—C12—C11 | 0.5 (5) | C26—C25—N4—Cu1 | −2.7 (4) |
N2—C11—C12—N1 | −1.0 (5) | C1—N1—Cu1—N3 | 57.0 (4) |
C7—C11—C12—N1 | 178.7 (3) | C12—N1—Cu1—N3 | −125.7 (2) |
N2—C11—C12—C4 | 180.0 (3) | C1—N1—Cu1—N2 | 178.6 (4) |
C7—C11—C12—C4 | −0.3 (5) | C12—N1—Cu1—N2 | −4.1 (2) |
N3—C15—C16—C17 | 0.5 (6) | C1—N1—Cu1—N4 | −55.8 (4) |
C28—C15—C16—C17 | 179.4 (4) | C12—N1—Cu1—N4 | 121.4 (2) |
C15—C16—C17—C18 | 0.5 (6) | C15—N3—Cu1—N1 | 54.0 (4) |
C16—C17—C18—C26 | −0.8 (6) | C26—N3—Cu1—N1 | −133.2 (2) |
C16—C17—C18—C19 | 178.9 (4) | C15—N3—Cu1—N2 | −54.9 (3) |
C26—C18—C19—C20 | 1.4 (6) | C26—N3—Cu1—N2 | 117.9 (2) |
C17—C18—C19—C20 | −178.3 (4) | C15—N3—Cu1—N4 | −179.4 (3) |
C18—C19—C20—C21 | −0.1 (6) | C26—N3—Cu1—N4 | −6.7 (2) |
C19—C20—C21—C25 | −2.8 (6) | C10—N2—Cu1—N1 | −175.9 (3) |
C19—C20—C21—C22 | 178.9 (4) | C11—N2—Cu1—N1 | 3.5 (2) |
C25—C21—C22—C23 | −1.2 (6) | C10—N2—Cu1—N3 | −36.7 (4) |
C20—C21—C22—C23 | 177.1 (4) | C11—N2—Cu1—N3 | 142.8 (2) |
C21—C22—C23—C24 | −0.5 (6) | C10—N2—Cu1—N4 | 62.4 (3) |
C22—C23—C24—N4 | 0.8 (6) | C11—N2—Cu1—N4 | −118.2 (2) |
C22—C23—C24—C27 | −179.5 (4) | C24—N4—Cu1—N1 | −34.5 (4) |
C22—C21—C25—N4 | 2.7 (5) | C25—N4—Cu1—N1 | 145.6 (2) |
C20—C21—C25—N4 | −175.7 (3) | C24—N4—Cu1—N3 | −175.0 (3) |
C22—C21—C25—C26 | −177.1 (3) | C25—N4—Cu1—N3 | 5.1 (2) |
C20—C21—C25—C26 | 4.6 (5) | C24—N4—Cu1—N2 | 67.9 (3) |
C17—C18—C26—N3 | 0.1 (5) | C25—N4—Cu1—N2 | −112.1 (2) |
C19—C18—C26—N3 | −179.6 (3) | O1—C29—C30—O2 | −1.6 (9) |
C17—C18—C26—C25 | −180.0 (3) | C32—C29—C30—O2 | 179.1 (5) |
C19—C18—C26—C25 | 0.3 (5) | O1—C29—C30—C31 | 179.5 (5) |
N4—C25—C26—N3 | −3.1 (5) | C32—C29—C30—C31 | 0.2 (3) |
C21—C25—C26—N3 | 176.6 (3) | O2—C30—C31—O3 | 0.3 (9) |
N4—C25—C26—C18 | 176.9 (3) | C29—C30—C31—O3 | 179.2 (5) |
C21—C25—C26—C18 | −3.3 (5) | O2—C30—C31—C32 | −179.1 (5) |
C2—C1—N1—C12 | −1.4 (6) | C29—C30—C31—C32 | −0.2 (3) |
C14—C1—N1—C12 | −179.2 (4) | O3—C31—C32—O4 | −0.2 (8) |
C2—C1—N1—Cu1 | 175.7 (3) | C30—C31—C32—O4 | 179.2 (5) |
C14—C1—N1—Cu1 | −2.0 (6) | O3—C31—C32—C29 | −179.2 (5) |
C4—C12—N1—C1 | 0.6 (5) | C30—C31—C32—C29 | 0.2 (3) |
C11—C12—N1—C1 | −178.3 (3) | O1—C29—C32—O4 | 1.5 (8) |
C4—C12—N1—Cu1 | −177.0 (3) | C30—C29—C32—O4 | −179.3 (4) |
C11—C12—N1—Cu1 | 4.0 (4) | O1—C29—C32—C31 | −179.5 (5) |
C9—C10—N2—C11 | 3.2 (5) | C30—C29—C32—C31 | −0.2 (3) |
D—H···A | D—H | H···A | D···A | D—H···A |
O4—H4···O3i | 0.93 (4) | 1.63 (5) | 2.535 (4) | 164 (4) |
C3—H3···O3ii | 0.93 | 2.44 | 3.227 (5) | 142 |
C6—H6···O1iii | 0.93 | 2.51 | 3.263 (5) | 139 |
C14—H14B···O5iv | 0.96 | 2.50 | 2.980 (11) | 111 |
C16—H16···O1 | 0.93 | 2.55 | 3.263 (5) | 134 |
Symmetry codes: (i) −x+1, −y+1, −z+1; (ii) x, y, z−1; (iii) −x+1, y+1/2, −z+1/2; (iv) x, −y+1/2, z−1/2. |
Experimental details
Crystal data | |
Chemical formula | [Cu(C14H12N2)2]C4HO4·0.5H2O |
Mr | 602.11 |
Crystal system, space group | Monoclinic, P21/c |
Temperature (K) | 297 |
a, b, c (Å) | 15.9664 (10), 13.7530 (12), 13.5082 (11) |
β (°) | 112.343 (6) |
V (Å3) | 2743.5 (4) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 0.84 |
Crystal size (mm) | 0.31 × 0.25 × 0.19 |
Data collection | |
Diffractometer | Stoe IPDS 2 diffractometer |
Absorption correction | Integration (X-RED32; Stoe & Cie, 2002) |
Tmin, Tmax | 0.728, 0.924 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 22893, 4828, 2280 |
Rint | 0.131 |
(sin θ/λ)max (Å−1) | 0.595 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.041, 0.075, 0.81 |
No. of reflections | 4828 |
No. of parameters | 387 |
No. of restraints | 3 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.17, −0.29 |
Computer programs: X-AREA (Stoe & Cie, 2002), X-AREA, X-RED32 (Stoe & Cie, 2002), SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), ORTEPIII (Farrugia, 1997), WinGX (Farrugia, 1999).
N1—Cu1 | 2.017 (2) | C29—C30 | 1.490 (6) |
N2—Cu1 | 2.053 (3) | C30—O2 | 1.211 (4) |
N3—Cu1 | 2.028 (3) | C30—C31 | 1.498 (5) |
N4—Cu1 | 2.059 (3) | C31—O3 | 1.251 (4) |
C29—O1 | 1.237 (4) | C31—C32 | 1.411 (5) |
C29—C32 | 1.434 (5) | C32—O4 | 1.308 (4) |
N1—Cu1—N3 | 136.87 (12) | N1—Cu1—N4 | 120.29 (11) |
N1—Cu1—N2 | 82.42 (11) | N3—Cu1—N4 | 82.02 (12) |
N3—Cu1—N2 | 116.84 (11) | N2—Cu1—N4 | 124.33 (11) |
D—H···A | D—H | H···A | D···A | D—H···A |
O4—H4···O3i | 0.93 (4) | 1.63 (5) | 2.535 (4) | 164 (4) |
C3—H3···O3ii | 0.93 | 2.44 | 3.227 (5) | 142 |
C6—H6···O1iii | 0.93 | 2.51 | 3.263 (5) | 139 |
C14—H14B···O5iv | 0.96 | 2.50 | 2.980 (11) | 111 |
C16—H16···O1 | 0.93 | 2.55 | 3.263 (5) | 134 |
Symmetry codes: (i) −x+1, −y+1, −z+1; (ii) x, y, z−1; (iii) −x+1, y+1/2, −z+1/2; (iv) x, −y+1/2, z−1/2. |
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Copper(I) complexes continue to be a subject of interest, not only due to their being inexpensive, environmentally friendly and flexible in coordination geometry, but also due to their rich photochemical and photophysical properties (Armaroli, 2001; Fu et al., 2004). Numerous early studies on copper(I) complexes with 2,9-substituted-1,10-phenanthroline were geared towards their use as metal-selective analytical tools (Diehl et al., 1972). More recently, there has been a renewed interest in the photochemical properties of copper(I) bis(1,10-phenanthroline) compounds as candidates for the development of photonic devices, including sensors, photovoltaic devices and switches (Castellano & Meyer, 1997; Miller & Karpishin, 1999; Baranoff et al., 2000). It is well known that copper complexes with 1,10-phenonthroline and their substituted derivatives generally exhibit low-energy metal-to-ligand charge-transfer (MLCT) states. In addition, the redox chemistry of copper phenanthroline is of particular interest, due to the fact that [Cu(phen)2]+,2+ undergoes a coordination change during redox processes, from a four-coordinate tetrahedral geometry in the CuI state to a five-coordinate (or six-coordinate) environment upon oxidation to CuII.
Squaric acid, H2SQ, is a very strong dibasic acid and has been studied for potential application to xerographic photoreceptors, organic solar cells and optical recording (Seitz & Imming, 1992; Liebeskind et al., 1993). It is also a useful tool for constructing crystalline architectures, because of its rigid and flat four-membered ring framework (Reetz et al., 1994). In our ongoing research on squaric acid, we have synthesized some mixed-ligand copper(II) complexes of squaric acid and their structures have been reported (Uçar et al., 2004; Bulut et al., 2004). In these compounds, the squaric acid is found as the dianion, SQ2−, while in the present study, the monoanion of squaric acid, HSQ−, is observed. To our knowledge, there are only a few examples of transition metal(I) complexes of hydrogen squarate (Braga et al., 2000), and no CuI complexes with hydrogen squarate acting as a counter-monoanion. In the present study, the title compound, (I), [Cu(dmphen)2]·HSq·0.5H2O, has been synthesized and its crystal structure (Fig. 1) is reported.
The CuI ion of (I) is bonded to two bidentate dmphen ligands through their N atoms and the coordination sphere is distorted away from ideal tetrahedral towards a trigonal–pyramidal geometry. The major distortion involves the wider N1—Cu1—N3 angle of 136.87 (12)° and the narrower N3—Cu1—N4 angle of 82.02 (12)°, due mostly to the five-membered chelate rings and the steric bulk of the ligands with methyl groups. The dihedral angle of 79.20 (12)° between the two CuNN planes is in agreement with the typical range of 70–80° for Cu(NN)2 (NN are substituted bipyridines and phenanthrolines; Bardwell et al., 1996; Bulut et al., 2004). The Cu1—N bond distances vary from 2.017 (2) to 2.059 (3) Å, which are within the normal range for [Cu(NN)2]+ complexes, where NN signifies substituted 1,10-phenanthroline (Dobson et al., 1984; Blake et al., 1998; Lemoine & Viossat, 2001). The internal geometric features of the dmphen ligands are in agreement with those established in previous studies (Kon et al., 1987; Kovalevsky et al., 2003).
The C—C distances in the planar squarate ring system of (I) reflect partial double-bond character for C31—C32 [1.411 (5) Å] and C29—C32 [1.434 (5) Å], and single-bond character for C30—C31 [1.498 (5) Å] and C29—C30 [1.490 (6) Å]. These lengths represent average values for the two possible resonance structures (see scheme). The bond distances of the carbonyl bonds are O1—C29 = 1.237 (4) Å and O3—C31 = 1.251 (4) Å, and these bond lengths indicate that the negative charge is located partially on atoms O1 and O3, whereas the O2—C30 distance [1.211 (4) Å] reflects double-bond character. The C—C and C—O distances observed for the HSQ− anion could, in principle, be interpreted equally well as the result of crystallographic disorder of a single resonance structure related to a second disorder component by rotation of 180° around the line joining C30 and C32.
The most remarkable structural feature of (I) is the extensive network of hydrogen bonds. The two squarate monoanions are linked by two strong negative charge-assisted O—H···O1/2- bonds, in which the O···O distance is 2.535 (4) Å, to form a head-to-head cyclic R22(10) dimer (Table 2). In carboxylic acid–carboxylate complexes, the shortest D···A distances belong to the negative-charge-assisted (-) CAHB class of [O—H···O]− bonds, for which O···O distances of 2.39–2.49 Å have been reported (Gilli et al., 1994; Bertolasi et al., 1996). However, in (I) this value lies at the upper end of the distribution. This is to be attributed to the fact that the formal charge on the acceptor O atom here is 1/2-, assuming that the resonance model holds for the HSQ− group. Such a dimeric unit has been found in a few other hydrogen squarates (Bertolasi et al., 2001; Mathew et al., 2002; Zaman et al., 2001). This self-recognition of the hydrogen squarate ions leads to the formation of stacked ribbons which propagate along the [100] direction (Fig. 2). In all other squarate structures, the squarate monoanions are linked by a single intermolecular O—H···O hydrogen bond and no ten-membered rings are formed.
In compound (I), the water molecule was refined with a site occupancy of 0.5 and the H atoms attached to atom O5 were not located. Fig. 2 shows all positions of the water atom O5, but it should be kept in mind that, according to the model refined, this atom is not present in all asymmetric units. The uncoordinated monoanion and complex cation are linked by intermolecular C—H···O hydrogen bonds (Table 2).
In the extended structure of (I), shown in Fig. 3, there are also π–π interactions. These intermolecular interactions occur between the two symmetry-related dmphen rings (ring A, C4–C7/C11/C12) of neighbouring molecules. Ring A is oriented in such a way that the perpendicular distance from A to Av is 3.485 Å, the closest interatomic distance being C6···C12v [3.522 (6) Å; symmetry code (v) 1 − x, 1 − y, −z]; the distance between the ring centroids is 3.525 (2) Å. The other π–π contact occurs between the dmphen ring B (N3/C15–C18/C26) and ring C (C18–C21/C25–C26). The perpendicular distance between rings B and C (C to Bvi) is 3.483 Å, the closest interatomic distance is C15···C19vi [3.494 (5) Å; symmetry code: (vi) −x, 1 − y, −z] and the dihedral angle between the planes of these rings is 1.74°. The distance between the ring centroids is 3.719 (2) Å. Additionally, there is also a π–π contact between rings B of neighbouring molecules. For the π–π stacking interaction, the perpendicular distance from B to Bvi is 3.514 Å, the closest interatomic distance being C17···C26vi [3.524 (5) Å]; the distance between the ring centroids is 3.746 (2) Å.