Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270103006760/av1132sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S0108270103006760/av1132Isup2.hkl |
CCDC reference: 214148
The title compound was prepared according to published patented procedures (Krätsmár-Šmogrovič et al., 1989, 1991). The reaction mixture, consituted of Cu(sal-DL-val) (10 mmol, 2.8 g) and KSCN (30 mmol, 2.9 g) resolved in ethanol/water (2:1 v/v, 50 ml) was heated and mixed vigorously for 20 min until the solid phase disappeared. The solution was filtered and left to cool to room temperature. Dark-green well developed crystals were isolated and analyzed. Analysis (Carlo-Erba 1180 instrument) calculated for C13H13CuKN2O3S: C 41.09, H 3.45, N 7.37%; found: C 40.71, H 3.40, N 7.38%.
All H atoms were fixed geometrically and refined isotropically. Three free variables were used for describing the Ueq values of H atoms during refinement, viz. two for H atoms attached to the methyl C11 and C12 atoms and one for H atoms at the aromatic C4, C5, C6 and C7 atoms.
Data collection: CrysAlis (Oxford Diffraction, 2002); cell refinement: CrysRed (Oxford Diffraction, 2002); data reduction: CrysRed; program(s) used to solve structure: SHELXS97 (Sheldrick, 1990); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEPIII (Johnson & Burnett, 1996); software used to prepare material for publication: SHELXL97, PARST (Nardelli, 1995).
2K+·2C13H13CuN2O3S+ | F(000) = 386 |
Mr = 759.0 | Dx = 1.753 Mg m−3 |
Triclinic, P1 | Melting point: 510 K |
a = 8.4753 (8) Å | Mo Kα radiation, λ = 0.71073 Å |
b = 9.5364 (8) Å | Cell parameters from 1760 reflections |
c = 10.1210 (11) Å | θ = 2.9–27.4° |
α = 76.128 (8)° | µ = 1.95 mm−1 |
β = 72.381 (9)° | T = 120 K |
γ = 69.917 (8)° | Prism, dark green |
V = 723.76 (12) Å3 | 0.50 × 0.20 × 0.20 mm |
Z = 1 |
Kuma KM-4-Plus CCD diffractometer | 2335 reflections with I > 2σ(I) |
Radiation source: fine-focus sealed tube | Rint = 0.050 |
Enhance (Oxford Diffraction) monochromator | θmax = 25.0°, θmin = 2.6° |
Detector resolution: 16.3 pixels mm-1 | h = −7→10 |
rotation method, ω–scan | k = −10→11 |
4202 measured reflections | l = −12→11 |
2479 independent 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)] = 0.030 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.112 | H-atom parameters constrained |
S = 0.98 | w = 1/[σ2(Fo2) + (0.075P)2 + 1.75P] where P = (Fo2 + 2Fc2)/3 |
2479 reflections | (Δ/σ)max < 0.001 |
197 parameters | Δρmax = 0.65 e Å−3 |
0 restraints | Δρmin = −0.82 e Å−3 |
2K+·2C13H13CuN2O3S+ | γ = 69.917 (8)° |
Mr = 759.0 | V = 723.76 (12) Å3 |
Triclinic, P1 | Z = 1 |
a = 8.4753 (8) Å | Mo Kα radiation |
b = 9.5364 (8) Å | µ = 1.95 mm−1 |
c = 10.1210 (11) Å | T = 120 K |
α = 76.128 (8)° | 0.50 × 0.20 × 0.20 mm |
β = 72.381 (9)° |
Kuma KM-4-Plus CCD diffractometer | 2335 reflections with I > 2σ(I) |
4202 measured reflections | Rint = 0.050 |
2479 independent reflections |
R[F2 > 2σ(F2)] = 0.030 | 0 restraints |
wR(F2) = 0.112 | H-atom parameters constrained |
S = 0.98 | Δρmax = 0.65 e Å−3 |
2479 reflections | Δρmin = −0.82 e Å−3 |
197 parameters |
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 | ||
Cu | 0.32825 (4) | 0.45525 (4) | 0.41296 (4) | 0.01254 (17) | |
K | 0.12073 (9) | 0.17080 (8) | 0.43660 (8) | 0.0181 (2) | |
S | −0.12495 (11) | 0.50485 (10) | 0.78906 (9) | 0.0194 (2) | |
O4 | 0.2126 (3) | 0.6614 (3) | 0.4483 (2) | 0.0160 (5) | |
O5 | 0.4450 (3) | 0.2515 (3) | 0.3862 (3) | 0.0176 (5) | |
N1 | 0.1572 (3) | 0.3884 (3) | 0.5766 (3) | 0.0158 (6) | |
O10 | 0.2324 (3) | 0.8947 (3) | 0.3921 (3) | 0.0195 (5) | |
N11 | 0.5134 (3) | 0.5361 (3) | 0.2967 (3) | 0.0119 (5) | |
C1 | 0.6663 (4) | 0.4535 (4) | 0.2458 (3) | 0.0132 (6) | |
H1 | 0.7536 | 0.5029 | 0.2036 | 0.011 (9)* | |
C2 | 0.7169 (4) | 0.2933 (4) | 0.2471 (3) | 0.0125 (6) | |
C3 | 0.6061 (4) | 0.2007 (4) | 0.3159 (3) | 0.0136 (6) | |
C4 | 0.6756 (4) | 0.0447 (4) | 0.3091 (4) | 0.0171 (7) | |
H4 | 0.6049 | −0.0200 | 0.3550 | 0.020 (5)* | |
C5 | 0.8434 (4) | −0.0161 (4) | 0.2375 (4) | 0.0182 (7) | |
H5 | 0.8863 | −0.1217 | 0.2345 | 0.020 (5)* | |
C6 | 0.9515 (4) | 0.0753 (4) | 0.1693 (4) | 0.0190 (7) | |
H6 | 1.0672 | 0.0329 | 0.1201 | 0.020 (5)* | |
C7 | 0.8873 (4) | 0.2273 (4) | 0.1749 (4) | 0.0170 (7) | |
H7 | 0.9602 | 0.2899 | 0.1285 | 0.020 (5)* | |
C8 | 0.2932 (4) | 0.7593 (4) | 0.3832 (3) | 0.0139 (7) | |
C9 | 0.4761 (4) | 0.7006 (4) | 0.2892 (3) | 0.0125 (6) | |
H9 | 0.5613 | 0.7176 | 0.3293 | 0.020* | |
C10 | 0.4862 (4) | 0.7923 (4) | 0.1400 (3) | 0.0151 (7) | |
H10 | 0.4341 | 0.9011 | 0.1519 | 0.020* | |
C11 | 0.3783 (5) | 0.7592 (4) | 0.0611 (4) | 0.0234 (8) | |
H11A | 0.3731 | 0.8316 | −0.0256 | 0.031 (7)* | |
H11B | 0.2609 | 0.7684 | 0.1201 | 0.031 (7)* | |
H11C | 0.4318 | 0.6564 | 0.0382 | 0.031 (7)* | |
C12 | 0.6704 (5) | 0.7757 (4) | 0.0509 (4) | 0.0235 (8) | |
H12A | 0.7203 | 0.6749 | 0.0231 | 0.032 (7)* | |
H12B | 0.7406 | 0.7890 | 0.1055 | 0.032 (7)* | |
H12C | 0.6687 | 0.8525 | −0.0330 | 0.032 (7)* | |
C13 | 0.0398 (4) | 0.4373 (3) | 0.6654 (3) | 0.0128 (7) |
U11 | U22 | U33 | U12 | U13 | U23 | |
Cu | 0.0085 (2) | 0.0095 (3) | 0.0170 (3) | −0.00110 (16) | −0.00037 (16) | −0.00301 (16) |
K | 0.0155 (4) | 0.0111 (4) | 0.0252 (4) | −0.0020 (3) | −0.0010 (3) | −0.0063 (3) |
S | 0.0145 (4) | 0.0239 (5) | 0.0189 (4) | −0.0056 (3) | 0.0013 (3) | −0.0085 (3) |
O4 | 0.0108 (11) | 0.0132 (12) | 0.0214 (12) | −0.0012 (9) | −0.0004 (9) | −0.0059 (9) |
O5 | 0.0120 (11) | 0.0119 (12) | 0.0241 (13) | −0.0023 (9) | 0.0027 (10) | −0.0050 (9) |
N1 | 0.0129 (13) | 0.0144 (14) | 0.0192 (15) | −0.0039 (11) | −0.0031 (12) | −0.0022 (11) |
O10 | 0.0197 (12) | 0.0116 (13) | 0.0234 (13) | 0.0010 (10) | −0.0035 (10) | −0.0060 (10) |
N11 | 0.0099 (12) | 0.0083 (13) | 0.0162 (14) | 0.0001 (10) | −0.0045 (11) | −0.0021 (10) |
C1 | 0.0108 (14) | 0.0165 (17) | 0.0138 (16) | −0.0046 (13) | −0.0047 (12) | −0.0022 (12) |
C2 | 0.0113 (15) | 0.0126 (16) | 0.0133 (16) | 0.0000 (12) | −0.0052 (12) | −0.0033 (12) |
C3 | 0.0129 (15) | 0.0129 (16) | 0.0134 (16) | 0.0000 (12) | −0.0052 (12) | −0.0022 (12) |
C4 | 0.0202 (17) | 0.0133 (17) | 0.0168 (17) | −0.0051 (13) | −0.0036 (14) | −0.0013 (13) |
C5 | 0.0201 (17) | 0.0094 (16) | 0.0218 (18) | 0.0036 (13) | −0.0072 (14) | −0.0053 (13) |
C6 | 0.0123 (15) | 0.0167 (17) | 0.0231 (18) | 0.0030 (13) | −0.0036 (13) | −0.0058 (14) |
C7 | 0.0111 (15) | 0.0165 (17) | 0.0223 (18) | −0.0028 (13) | −0.0032 (13) | −0.0042 (13) |
C8 | 0.0121 (15) | 0.0133 (17) | 0.0162 (16) | 0.0005 (13) | −0.0064 (13) | −0.0043 (12) |
C9 | 0.0112 (15) | 0.0084 (16) | 0.0182 (17) | −0.0013 (12) | −0.0044 (12) | −0.0037 (12) |
C10 | 0.0162 (16) | 0.0090 (16) | 0.0169 (17) | −0.0016 (12) | −0.0027 (13) | −0.0007 (12) |
C11 | 0.0261 (19) | 0.0230 (19) | 0.0223 (19) | −0.0063 (15) | −0.0114 (15) | 0.0004 (14) |
C12 | 0.0195 (18) | 0.0229 (19) | 0.0219 (18) | −0.0064 (15) | 0.0009 (14) | 0.0007 (14) |
C13 | 0.0130 (15) | 0.0110 (16) | 0.0170 (17) | −0.0055 (12) | −0.0081 (14) | 0.0020 (12) |
Cu—O5 | 1.897 (2) | N11—C9 | 1.478 (4) |
Cu—N11 | 1.929 (3) | C1—C2 | 1.436 (5) |
Cu—O4 | 1.938 (2) | C1—H1 | 0.9500 |
Cu—N1 | 1.982 (3) | C2—C7 | 1.405 (5) |
Cu—Si | 2.9332 (10) | C2—C3 | 1.423 (5) |
Cu—N11ii | 3.608 (3) | C3—C4 | 1.410 (5) |
Cu—Cuii | 4.2238 (8) | C4—C5 | 1.377 (5) |
Cu—Cui | 5.1300 (9) | C4—Kiv | 3.398 (3) |
Cu—K | 3.6359 (8) | C4—H4 | 0.9500 |
K—O10iii | 2.575 (2) | C5—C6 | 1.398 (5) |
K—O4i | 2.774 (2) | C5—Kiv | 3.333 (4) |
K—N1 | 2.920 (3) | C5—H5 | 0.9500 |
K—O5 | 2.970 (2) | C6—C7 | 1.371 (5) |
K—O10i | 3.159 (3) | C6—H6 | 0.9500 |
K—C5iv | 3.333 (4) | C7—H7 | 0.9500 |
K—C8i | 3.344 (3) | C8—C9 | 1.545 (4) |
K—Si | 3.3800 (12) | C8—Ki | 3.344 (3) |
K—C4iv | 3.398 (3) | C9—C10 | 1.546 (4) |
K—C13i | 3.520 (3) | C9—H9 | 1.0000 |
K—Kv | 4.1750 (14) | C10—C12 | 1.524 (5) |
S—C13 | 1.625 (3) | C10—C11 | 1.527 (5) |
S—Ki | 3.3800 (12) | C10—H10 | 1.0000 |
O4—C8 | 1.281 (4) | C11—H11A | 0.9800 |
O4—Ki | 2.774 (2) | C11—H11B | 0.9800 |
O5—C3 | 1.314 (4) | C11—H11C | 0.9800 |
N1—C13 | 1.164 (4) | C12—H12A | 0.9800 |
O10—C8 | 1.230 (4) | C12—H12B | 0.9800 |
O10—Kvi | 2.575 (2) | C12—H12C | 0.9800 |
O10—Ki | 3.159 (3) | C13—Ki | 3.520 (3) |
N11—C1 | 1.286 (4) | ||
O5—Cu—N11 | 96.19 (11) | C13i—K—Kv | 131.58 (6) |
O5—Cu—O4 | 177.31 (10) | Cu—K—Kv | 166.55 (3) |
N11—Cu—O4 | 84.05 (10) | C13—S—Ki | 81.25 (11) |
O5—Cu—N1 | 90.14 (11) | C8—O4—Cu | 116.7 (2) |
N11—Cu—N1 | 162.93 (12) | C8—O4—Ki | 105.04 (19) |
O4—Cu—N1 | 88.90 (11) | Cu—O4—Ki | 136.82 (11) |
O5—Cu—Si | 91.61 (8) | C3—O5—Cu | 125.5 (2) |
N11—Cu—Si | 101.21 (8) | C3—O5—K | 135.2 (2) |
O4—Cu—Si | 90.97 (7) | Cu—O5—K | 94.07 (9) |
N1—Cu—Si | 94.41 (8) | C13—N1—Cu | 140.3 (3) |
O5—Cu—K | 54.57 (7) | C13—N1—K | 116.8 (2) |
N11—Cu—K | 141.81 (8) | Cu—N1—K | 93.79 (10) |
O4—Cu—K | 126.38 (7) | C8—O10—Kvi | 173.1 (2) |
N1—Cu—K | 53.26 (8) | C8—O10—Ki | 87.74 (19) |
Si—Cu—K | 60.82 (2) | Kvi—O10—Ki | 92.90 (7) |
O10iii—K—O4i | 129.32 (8) | C1—N11—C9 | 121.1 (3) |
O10iii—K—N1 | 145.14 (8) | C1—N11—Cu | 123.6 (2) |
O4i—K—N1 | 73.68 (7) | C9—N11—Cu | 114.6 (2) |
O10iii—K—O5 | 102.93 (7) | N11—C1—C2 | 125.8 (3) |
O4i—K—O5 | 126.84 (7) | N11—C1—H1 | 117.1 |
N1—K—O5 | 55.58 (7) | C2—C1—H1 | 117.1 |
O10iii—K—O10i | 87.10 (7) | C7—C2—C3 | 119.4 (3) |
O4i—K—O10i | 43.17 (6) | C7—C2—C1 | 116.4 (3) |
N1—K—O10i | 105.31 (7) | C3—C2—C1 | 124.2 (3) |
O5—K—O10i | 157.55 (7) | O5—C3—C4 | 118.5 (3) |
O10iii—K—C5iv | 83.89 (8) | O5—C3—C2 | 124.1 (3) |
O4i—K—C5iv | 87.75 (8) | C4—C3—C2 | 117.4 (3) |
N1—K—C5iv | 69.90 (8) | C5—C4—C3 | 121.6 (3) |
O5—K—C5iv | 88.88 (8) | C5—C4—Kiv | 75.6 (2) |
O10i—K—C5iv | 72.06 (8) | C3—C4—Kiv | 116.5 (2) |
O10iii—K—C8i | 108.50 (8) | C5—C4—H4 | 119.2 |
O4i—K—C8i | 21.72 (8) | C3—C4—H4 | 119.2 |
N1—K—C8i | 88.51 (8) | Kiv—C4—H4 | 78.3 |
O5—K—C8i | 144.08 (8) | C4—C5—C6 | 120.9 (3) |
O10i—K—C8i | 21.56 (7) | C4—C5—Kiv | 80.8 (2) |
C5iv—K—C8i | 77.79 (8) | C6—C5—Kiv | 113.7 (2) |
O10iii—K—Si | 130.57 (6) | C4—C5—H5 | 119.6 |
O4i—K—Si | 82.90 (5) | C6—C5—H5 | 119.6 |
N1—K—Si | 70.69 (6) | Kiv—C5—H5 | 75.8 |
O5—K—Si | 67.35 (5) | C7—C6—C5 | 118.7 (3) |
O10i—K—Si | 120.82 (5) | C7—C6—H6 | 120.6 |
C5iv—K—Si | 140.55 (7) | C5—C6—H6 | 120.6 |
C8i—K—Si | 102.85 (6) | C6—C7—C2 | 122.0 (3) |
O10iii—K—C4iv | 71.63 (8) | C6—C7—H7 | 119.0 |
O4i—K—C4iv | 111.16 (8) | C2—C7—H7 | 119.0 |
N1—K—C4iv | 75.46 (8) | O10—C8—O4 | 123.5 (3) |
O5—K—C4iv | 72.89 (8) | O10—C8—C9 | 119.5 (3) |
O10i—K—C4iv | 91.85 (7) | O4—C8—C9 | 117.0 (3) |
C5iv—K—C4iv | 23.58 (8) | O10—C8—Ki | 70.70 (18) |
C8i—K—C4iv | 100.81 (8) | O4—C8—Ki | 53.24 (15) |
Si—K—C4iv | 137.72 (6) | C9—C8—Ki | 167.7 (2) |
O10iii—K—C13i | 153.06 (8) | N11—C9—C8 | 107.6 (2) |
O4i—K—C13i | 57.15 (7) | N11—C9—C10 | 115.1 (3) |
N1—K—C13i | 58.47 (8) | C8—C9—C10 | 109.5 (3) |
O5—K—C13i | 81.56 (7) | N11—C9—H9 | 108.1 |
O10i—K—C13i | 98.66 (7) | C8—C9—H9 | 108.1 |
C5iv—K—C13i | 122.96 (8) | C10—C9—H9 | 108.1 |
C8i—K—C13i | 78.33 (8) | C12—C10—C11 | 110.3 (3) |
Si—K—C13i | 27.15 (5) | C12—C10—C9 | 113.8 (3) |
C4iv—K—C13i | 133.91 (8) | C11—C10—C9 | 112.7 (3) |
O10iii—K—Cu | 134.21 (6) | C12—C10—H10 | 106.5 |
O4i—K—Cu | 96.16 (5) | C11—C10—H10 | 106.5 |
N1—K—Cu | 32.94 (6) | C9—C10—H10 | 106.5 |
O5—K—Cu | 31.36 (5) | C10—C11—H11A | 109.5 |
O10i—K—Cu | 135.82 (5) | C10—C11—H11B | 109.5 |
C5iv—K—Cu | 94.26 (6) | H11A—C11—H11B | 109.5 |
C8i—K—Cu | 115.80 (6) | C10—C11—H11C | 109.5 |
Si—K—Cu | 49.262 (19) | H11A—C11—H11C | 109.5 |
C4iv—K—Cu | 88.84 (6) | H11B—C11—H11C | 109.5 |
C13i—K—Cu | 53.32 (5) | C10—C12—H12A | 109.5 |
O10iii—K—Kv | 49.08 (6) | C10—C12—H12B | 109.5 |
O4i—K—Kv | 80.74 (5) | H12A—C12—H12B | 109.5 |
N1—K—Kv | 134.89 (6) | C10—C12—H12C | 109.5 |
O5—K—Kv | 146.84 (6) | H12A—C12—H12C | 109.5 |
O10i—K—Kv | 38.02 (4) | H12B—C12—H12C | 109.5 |
C5iv—K—Kv | 72.62 (6) | N1—C13—S | 179.6 (3) |
C8i—K—Kv | 59.47 (6) | N1—C13—Ki | 108.5 (2) |
Si—K—Kv | 142.07 (3) | S—C13—Ki | 71.61 (11) |
C4iv—K—Kv | 80.21 (6) |
Symmetry codes: (i) −x, −y+1, −z+1; (ii) −x+1, −y+1, −z+1; (iii) x, y−1, z; (iv) −x+1, −y, −z+1; (v) −x, −y, −z+1; (vi) x, y+1, z. |
Experimental details
Crystal data | |
Chemical formula | 2K+·2C13H13CuN2O3S+ |
Mr | 759.0 |
Crystal system, space group | Triclinic, P1 |
Temperature (K) | 120 |
a, b, c (Å) | 8.4753 (8), 9.5364 (8), 10.1210 (11) |
α, β, γ (°) | 76.128 (8), 72.381 (9), 69.917 (8) |
V (Å3) | 723.76 (12) |
Z | 1 |
Radiation type | Mo Kα |
µ (mm−1) | 1.95 |
Crystal size (mm) | 0.50 × 0.20 × 0.20 |
Data collection | |
Diffractometer | Kuma KM-4-Plus CCD diffractometer |
Absorption correction | – |
No. of measured, independent and observed [I > 2σ(I)] reflections | 4202, 2479, 2335 |
Rint | 0.050 |
(sin θ/λ)max (Å−1) | 0.595 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.030, 0.112, 0.98 |
No. of reflections | 2479 |
No. of parameters | 197 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.65, −0.82 |
Computer programs: CrysAlis (Oxford Diffraction, 2002), CrysRed (Oxford Diffraction, 2002), CrysRed, SHELXS97 (Sheldrick, 1990), SHELXL97 (Sheldrick, 1997), ORTEPIII (Johnson & Burnett, 1996), SHELXL97, PARST (Nardelli, 1995).
Cu—O5 | 1.897 (2) | K—O5 | 2.970 (2) |
Cu—N11 | 1.929 (3) | S—C13 | 1.625 (3) |
Cu—O4 | 1.938 (2) | N1—C13 | 1.164 (4) |
Cu—N1 | 1.982 (3) | N11—C1 | 1.286 (4) |
K—N1 | 2.920 (3) | ||
O5—Cu—N11 | 96.19 (11) | C13—N1—Cu | 140.3 (3) |
O5—Cu—O4 | 177.31 (10) | C1—N11—Cu | 123.6 (2) |
N11—Cu—O4 | 84.05 (10) | N11—C1—C2 | 125.8 (3) |
O5—Cu—N1 | 90.14 (11) | N11—C9—C10 | 115.1 (3) |
N11—Cu—N1 | 162.93 (12) | N1—C13—S | 179.6 (3) |
O4—Cu—N1 | 88.90 (11) |
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Copper(II) complexes of tridentate Schiff bases (TSB) derived from salicylaldehyde and amino acids are of interest not only as simple structural models of more complicated bioinorganic systems, such as SOD-mimic activity (Bergendi et al., 1991; Valentová et al., 1995) or vitamin B6-mimic activities (Metzler et al., 1954; Koh et al., 1996), but also for their antimicrobial (Sokolík et al., 1997), antifungal (Švajlenová et al., 2002), antipyretic and immunoprotective activities. Another interesting feature of Cu–TSB complexes is the coordination geometry around the metal ion. If an additional ligand is present, square-pyramidal(4 + 1) complexes with an elongated bond distance (bond lengths up to 3 Å) between the central atom and the donor atom situated at the apex of pyramid (Friebel et al., 1997) are usually formed, and resulting units can be further involved in the formation of dimeric (Pavelčík et al., 1981; Werner et al., 1983; Warda, 1997, 1998a) or even polymeric (Warda, 1998b) structures. The impulse for studying the title derivative of the (N-salicylidene-DL-valinato-O,N,O')copper(II) complex was not only the difference between the magnetic and spectral (UV-VIS, ESR) properties of Cu(sal-DL-val) (Švajlenová et al., 1978) and dimeric Cu(sal-L-val)(H2O) (Korhonen et al., 1979), but also the proposed significant biological activities discovered in other Cu–TSB complexes.
The title dimeric µ-isothiocyanato copper(II) complex, (I), was prepared by reaction of Cu(sal-DL-val) with thiocyanate anions in an ethanol/aqueous solution. The spectral and ESR properties of this type of compound indicate a square-pyramidal environment around the CuII atom (Kettmann et al., 1989, 1992; Sivý et al., 1990). As a direct proof of this assumption, we report here the crystal structure of (I).
The dimer (I) consists of [Cu(sal-D-val)(NCS)] and [Cu(sal-L-val)(NCS)] coordination units. The copper ions adopt 4 + 1 square-pyramidal geometry defined by the tridentate N-salicylidene-D-valinato-O,N,O' (or –L-valinato-) dianions and the N atom of of the NCS− ligand in the basal plane. The apical position is occupied by the Si atom from a neighbouring molecule, with a Cu–S distance of 2.9332 (10) Å [symmetry code: (i) −x, 1 − y, 1 − z]. This length is comparable to the average length 2.88 Å of this bond in related complexes in the Cambridge Structural Database (Version 5.24.1; Allen, 2002).
The mean plane through Cu and the four basal atoms shows that the N atom of the NCS− ligand is significantly [with deviation 0.532 (3) Å] shifted. The five-membered chelate and phenyl rings of the (sal-val) moiety are nearly planar (the average deviations of contributing atoms from the least-squares planes are 0.013 and 0.002 Å, respectively). The six-membered chelate ring is more deformed; atom N11 is displaced by 0.120 (3) Å from the mean plane through the five remaining atoms (their average deviation from the plane is 0.006 Å; the Cremer & Pople (1975) puckering parameters for the ring are Q = 0.083 (3) Å, Θ = 51 (2)°, ϕ2 =46 (3)°]. The angles between the planes of the phenyl and six-membered chelate rings and between the planes of the six-membered and five-membered chelate rings are 1.46 (7)° and 4.40 (7)°, respectively.
The crystal packing is dominated by Coulomb interactions between the K+ ions and the heteroatoms of the neighbouring dimeric anions, which leads to the formation of one-dimensional chains of molecules through the crystal in the [010] direction. The coordination number of the K+ ion is 6.
The chelate ring system resulting from the TSB coordination could show metaloaromaticity (Masui, 2001) and related interactions. In crystals of (I), we observed the superposition of normals of pyramidal base planes, with possible π–π interactions in a direction close to [001].