Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270100004662/gs1082sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S0108270100004662/gs1082Isup2.hkl | |
Structure factor file (CIF format) https://doi.org/10.1107/S0108270100004662/gs1082IIsup3.hkl |
CCDC references: 147610; 147611
H atoms were located on stereochemical grounds and refined with fixed geometry, each riding on a carrier atom, with an isotropic displacement parameter amounting to 1.5 (for methyl H atoms) or 1.2 (for the other H atoms) times the value of the equivalent isotropic displacement parameter of the atom to which they were attached.
For both compounds, data collection: CAD-4 Software (Enraf-Nonius,1989); cell refinement: CAD-4 Software; data reduction: MolEN (Fair, 1990); program(s) used to solve structure: SHELXS86 (Sheldrick, 1990); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ZORTEP (Zsolnai, 1995); software used to prepare material for publication: SHELXL97.
[Ni(C5H7O2)2(C6H4N2)2] | F(000) = 484.0 |
Mr = 465.14 | Dx = 1.398 Mg m−3 |
Monoclinic, P21/a | Mo Kα radiation, λ = 0.71073 Å |
a = 7.8295 (6) Å | Cell parameters from 25 reflections |
b = 19.3334 (18) Å | θ = 8.9–12.9° |
c = 8.1244 (10) Å | µ = 0.91 mm−1 |
β = 116.019 (8)° | T = 293 K |
V = 1105.16 (19) Å3 | Irregular, blue |
Z = 2 | 0.20 × 0.18 × 0.05 mm |
Enraf-Nonius CAD4 diffractometer | 1131 reflections with F2 > 2σF2 |
Radiation source: fine-focus sealed tube | Rint = 0.022 |
Graphite monochromator | θmax = 27.5° |
ω/2θ scans | h = −10→0 |
Absorption correction: ψ-scan (North et al., 1968) | k = 0→25 |
Tmin = 0.839, Tmax = 0.956 | l = −9→10 |
2737 measured reflections | 3 standard reflections every 30 min |
2529 independent reflections | intensity decay: 0.8% |
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)] = 0.045 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.115 | H-atom parameters constrained |
S = 0.95 | Calculated w = 1/[σ2(Fo2) + (0.0418P)2] where P = (Fo2 + 2Fc2)/3 |
2529 reflections | (Δ/σ)max < 0.001 |
144 parameters | Δρmax = 0.27 e Å−3 |
0 restraints | Δρmin = −0.59 e Å−3 |
[Ni(C5H7O2)2(C6H4N2)2] | V = 1105.16 (19) Å3 |
Mr = 465.14 | Z = 2 |
Monoclinic, P21/a | Mo Kα radiation |
a = 7.8295 (6) Å | µ = 0.91 mm−1 |
b = 19.3334 (18) Å | T = 293 K |
c = 8.1244 (10) Å | 0.20 × 0.18 × 0.05 mm |
β = 116.019 (8)° |
Enraf-Nonius CAD4 diffractometer | 1131 reflections with F2 > 2σF2 |
Absorption correction: ψ-scan (North et al., 1968) | Rint = 0.022 |
Tmin = 0.839, Tmax = 0.956 | 3 standard reflections every 30 min |
2737 measured reflections | intensity decay: 0.8% |
2529 independent reflections |
R[F2 > 2σ(F2)] = 0.045 | 0 restraints |
wR(F2) = 0.115 | H-atom parameters constrained |
S = 0.95 | Δρmax = 0.27 e Å−3 |
2529 reflections | Δρmin = −0.59 e Å−3 |
144 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 on F2 for ALL reflections. Weighted R-factors wR and all goodnesses of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The observed criterion of F2 > σ(F2) is used only for calculating R-factor-obs 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 | ||
Ni | 1/2 | 1/2 | 1/2 | 0.0437 (2) | |
N1 | 0.5981 (4) | 0.39799 (16) | 0.5000 (4) | 0.0465 (8) | |
N2 | 0.6458 (7) | 0.2566 (2) | 0.0414 (6) | 0.0910 (14) | |
O1 | 0.7482 (3) | 0.52655 (13) | 0.7096 (3) | 0.0501 (7) | |
O2 | 0.5928 (4) | 0.52834 (13) | 0.3144 (3) | 0.0514 (7) | |
C1 | 1.0398 (5) | 0.5839 (2) | 0.8702 (5) | 0.0673 (13) | |
H1A | 1.0030 | 0.6237 | 0.9176 | 0.101* | |
H1B | 1.1471 | 0.5954 | 0.8477 | 0.101* | |
H1C | 1.0736 | 0.5470 | 0.9577 | 0.101* | |
C2 | 0.8758 (5) | 0.56139 (19) | 0.6930 (5) | 0.0478 (10) | |
C3 | 0.8762 (6) | 0.5805 (2) | 0.5280 (6) | 0.0561 (11) | |
H3 | 0.9767 | 0.6081 | 0.5360 | 0.067* | |
C4 | 0.7418 (6) | 0.56265 (18) | 0.3512 (6) | 0.0489 (10) | |
C5 | 0.7715 (7) | 0.5869 (2) | 0.1899 (6) | 0.0763 (14) | |
H5A | 0.7210 | 0.5533 | 0.0935 | 0.114* | |
H5B | 0.9050 | 0.5928 | 0.2261 | 0.114* | |
H5C | 0.7075 | 0.6303 | 0.1470 | 0.114* | |
C6 | 0.5906 (5) | 0.3700 (2) | 0.3473 (5) | 0.0488 (10) | |
H6 | 0.5409 | 0.3960 | 0.2402 | 0.059* | |
C7 | 0.6537 (5) | 0.3040 (2) | 0.3418 (5) | 0.0477 (10) | |
C8 | 0.7266 (6) | 0.2645 (2) | 0.4990 (6) | 0.0646 (13) | |
H8 | 0.7694 | 0.2197 | 0.4981 | 0.078* | |
C9 | 0.7342 (6) | 0.2927 (2) | 0.6551 (6) | 0.0698 (13) | |
H9 | 0.7822 | 0.2675 | 0.7635 | 0.084* | |
C10 | 0.6701 (6) | 0.3590 (2) | 0.6508 (5) | 0.0559 (11) | |
H10 | 0.6773 | 0.3779 | 0.7590 | 0.067* | |
C11 | 0.6471 (6) | 0.2771 (2) | 0.1729 (7) | 0.0618 (12) |
U11 | U22 | U33 | U12 | U13 | U23 | |
Ni | 0.0470 (4) | 0.0449 (4) | 0.0366 (3) | −0.0093 (4) | 0.0159 (3) | −0.0015 (4) |
N1 | 0.0474 (18) | 0.0511 (19) | 0.0377 (17) | −0.0056 (16) | 0.0156 (15) | −0.0019 (16) |
N2 | 0.107 (3) | 0.091 (3) | 0.089 (3) | −0.022 (3) | 0.057 (3) | −0.034 (3) |
O1 | 0.0479 (15) | 0.0553 (17) | 0.0417 (15) | −0.0102 (13) | 0.0147 (12) | 0.0037 (11) |
O2 | 0.0563 (16) | 0.0561 (16) | 0.0445 (15) | −0.0092 (14) | 0.0247 (13) | −0.0022 (12) |
C1 | 0.060 (3) | 0.063 (3) | 0.057 (3) | −0.018 (2) | 0.006 (2) | −0.005 (2) |
C2 | 0.046 (2) | 0.039 (2) | 0.053 (2) | 0.0002 (19) | 0.017 (2) | 0.0005 (19) |
C3 | 0.050 (2) | 0.056 (3) | 0.064 (3) | −0.017 (2) | 0.026 (2) | 0.001 (2) |
C4 | 0.058 (3) | 0.035 (2) | 0.062 (3) | 0.004 (2) | 0.034 (2) | 0.0051 (19) |
C5 | 0.092 (4) | 0.082 (3) | 0.072 (3) | −0.017 (3) | 0.052 (3) | 0.007 (3) |
C6 | 0.053 (2) | 0.046 (2) | 0.042 (2) | −0.004 (2) | 0.0164 (19) | 0.0031 (19) |
C7 | 0.043 (2) | 0.049 (3) | 0.051 (2) | −0.0112 (19) | 0.0206 (19) | −0.008 (2) |
C8 | 0.063 (3) | 0.051 (3) | 0.074 (3) | 0.001 (2) | 0.025 (2) | 0.006 (3) |
C9 | 0.075 (3) | 0.065 (3) | 0.057 (3) | 0.007 (3) | 0.018 (2) | 0.015 (2) |
C10 | 0.057 (3) | 0.065 (3) | 0.037 (2) | −0.006 (2) | 0.0123 (19) | 0.001 (2) |
C11 | 0.063 (3) | 0.051 (3) | 0.076 (3) | −0.013 (2) | 0.035 (3) | −0.009 (2) |
Ni—O1 | 2.009 (2) | C2—C3 | 1.392 (5) |
Ni—O2 | 2.016 (2) | C3—C4 | 1.401 (5) |
Ni—N1 | 2.116 (3) | C4—C5 | 1.503 (5) |
N1—C6 | 1.331 (4) | C6—C7 | 1.376 (5) |
N1—C10 | 1.335 (5) | C7—C8 | 1.379 (5) |
N2—C11 | 1.135 (5) | C7—C11 | 1.447 (6) |
O1—C2 | 1.260 (4) | C8—C9 | 1.358 (6) |
O2—C4 | 1.258 (4) | C9—C10 | 1.371 (6) |
C1—C2 | 1.513 (5) | ||
O1i—Ni—O2i | 91.86 (10) | C3—C2—C1 | 118.7 (4) |
O1—Ni—O2i | 88.14 (10) | C2—C3—C4 | 127.2 (4) |
O1—Ni—O2 | 91.86 (10) | O2—C4—C3 | 125.1 (4) |
O1i—Ni—N1 | 88.73 (11) | O2—C4—C5 | 116.1 (4) |
O1—Ni—N1 | 91.27 (11) | C3—C4—C5 | 118.9 (4) |
O2i—Ni—N1 | 89.81 (11) | N1—C6—C7 | 122.5 (3) |
O2—Ni—N1 | 90.19 (11) | C6—C7—C8 | 119.5 (4) |
C6—N1—C10 | 117.0 (3) | C6—C7—C11 | 119.9 (4) |
C6—N1—Ni | 120.8 (2) | C8—C7—C11 | 120.5 (4) |
C10—N1—Ni | 122.2 (3) | C9—C8—C7 | 118.2 (4) |
C2—O1—Ni | 124.3 (2) | C8—C9—C10 | 119.1 (4) |
C4—O2—Ni | 124.5 (3) | N1—C10—C9 | 123.6 (4) |
O1—C2—C3 | 125.6 (4) | N2—C11—C7 | 178.5 (5) |
O1—C2—C1 | 115.7 (3) |
Symmetry code: (i) −x+1, −y+1, −z+1. |
[Ni(C5H7O2)2(C6H4N2)2] | Z = 1 |
Mr = 465.14 | F(000) = 242 |
Triclinic, P1 | Dx = 1.379 Mg m−3 |
a = 6.2795 (6) Å | Mo Kα radiation, λ = 0.71073 Å |
b = 9.912 (1) Å | Cell parameters from 25 reflections |
c = 10.392 (1) Å | θ = 8.2–13.9° |
α = 64.96 (1)° | µ = 0.90 mm−1 |
β = 86.441 (8)° | T = 293 K |
γ = 73.333 (9)° | Irregular, blue |
V = 560.10 (9) Å3 | 0.22 × 0.18 × 0.05 mm |
Enraf-Nonius CAD4 diffractometer | 1605 reflections with I > 2σ(I) |
Radiation source: fine-focus sealed tube | Rint = 0.022 |
Graphite monochromator | θmax = 25.5° |
ω/2θ scans | h = −7→7 |
Absorption correction: ψ-scan (North et al., 1968) | k = −11→10 |
Tmin = 0.855, Tmax = 0.961 | l = −12→0 |
2180 measured reflections | 3 standard reflections every 60 min |
2059 independent reflections | intensity decay: 1.1% |
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)] = 0.035 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.084 | H-atom parameters constrained |
S = 1.06 | Calculated w = 1/[σ2(Fo2) + (0.029P)2 + 0.1589P] where P = (Fo2 + 2Fc2)/3 |
2059 reflections | (Δ/σ)max < 0.001 |
144 parameters | Δρmax = 0.28 e Å−3 |
0 restraints | Δρmin = −0.26 e Å−3 |
[Ni(C5H7O2)2(C6H4N2)2] | γ = 73.333 (9)° |
Mr = 465.14 | V = 560.10 (9) Å3 |
Triclinic, P1 | Z = 1 |
a = 6.2795 (6) Å | Mo Kα radiation |
b = 9.912 (1) Å | µ = 0.90 mm−1 |
c = 10.392 (1) Å | T = 293 K |
α = 64.96 (1)° | 0.22 × 0.18 × 0.05 mm |
β = 86.441 (8)° |
Enraf-Nonius CAD4 diffractometer | 1605 reflections with I > 2σ(I) |
Absorption correction: ψ-scan (North et al., 1968) | Rint = 0.022 |
Tmin = 0.855, Tmax = 0.961 | 3 standard reflections every 60 min |
2180 measured reflections | intensity decay: 1.1% |
2059 independent reflections |
R[F2 > 2σ(F2)] = 0.035 | 0 restraints |
wR(F2) = 0.084 | H-atom parameters constrained |
S = 1.06 | Δρmax = 0.28 e Å−3 |
2059 reflections | Δρmin = −0.26 e Å−3 |
144 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 on F2 for ALL reflections. Weighted R-factors wR and all goodnesses of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The observed criterion of F2 > σ(F2) is used only for calculating R-factor-obs 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 | ||
Ni | 0 | 0 | 0 | 0.03738 (18) | |
O1 | 0.1401 (3) | 0.1561 (2) | 0.00617 (18) | 0.0430 (4) | |
O2 | −0.1764 (3) | 0.0057 (2) | 0.16829 (19) | 0.0459 (5) | |
N1 | 0.2667 (3) | −0.1908 (2) | 0.1456 (2) | 0.0411 (5) | |
N2 | 0.9547 (5) | −0.6553 (3) | 0.4737 (4) | 0.0932 (11) | |
C1 | 0.1161 (4) | 0.2085 (3) | 0.0995 (3) | 0.0441 (7) | |
C2 | 0.2506 (5) | 0.3191 (4) | 0.0818 (4) | 0.0646 (9) | |
H2A | 0.4059 | 0.2680 | 0.0826 | 0.097* | |
H2B | 0.2271 | 0.3501 | 0.1587 | 0.097* | |
H2C | 0.2041 | 0.4092 | −0.0070 | 0.097* | |
C3 | −0.0168 (5) | 0.1715 (3) | 0.2133 (3) | 0.0555 (8) | |
H3 | −0.0146 | 0.2150 | 0.2767 | 0.067* | |
C4 | −0.1543 (5) | 0.0746 (3) | 0.2417 (3) | 0.0463 (7) | |
C5 | −0.2871 (6) | 0.0467 (4) | 0.3723 (3) | 0.0663 (9) | |
H5A | −0.4397 | 0.0633 | 0.3464 | 0.099* | |
H5B | −0.2793 | 0.1173 | 0.4115 | 0.099* | |
H5C | −0.2265 | −0.0584 | 0.4419 | 0.099* | |
C6 | 0.4438 (4) | −0.1654 (3) | 0.1852 (3) | 0.0465 (7) | |
H6 | 0.4489 | −0.0633 | 0.1511 | 0.056* | |
C7 | 0.6197 (4) | −0.2818 (3) | 0.2739 (3) | 0.0494 (7) | |
H7 | 0.7386 | −0.2584 | 0.3002 | 0.059* | |
C8 | 0.6158 (5) | −0.4325 (3) | 0.3224 (3) | 0.0474 (7) | |
C9 | 0.4319 (5) | −0.4613 (3) | 0.2838 (3) | 0.0626 (9) | |
H9 | 0.4229 | −0.5624 | 0.3164 | 0.075* | |
C10 | 0.2639 (5) | −0.3380 (3) | 0.1966 (3) | 0.0563 (8) | |
H10 | 0.1407 | −0.3582 | 0.1716 | 0.068* | |
C11 | 0.8035 (6) | −0.5584 (4) | 0.4092 (3) | 0.0601 (8) |
U11 | U22 | U33 | U12 | U13 | U23 | |
Ni | 0.0367 (3) | 0.0398 (3) | 0.0407 (3) | −0.0128 (2) | −0.0009 (2) | −0.0201 (2) |
O1 | 0.0433 (10) | 0.0460 (11) | 0.0477 (11) | −0.0173 (8) | −0.0002 (8) | −0.0242 (9) |
O2 | 0.0457 (11) | 0.0507 (11) | 0.0476 (11) | −0.0169 (9) | 0.0045 (9) | −0.0250 (9) |
N1 | 0.0386 (12) | 0.0421 (13) | 0.0433 (13) | −0.0117 (10) | −0.0031 (10) | −0.0178 (11) |
N2 | 0.097 (2) | 0.0628 (19) | 0.106 (3) | 0.0196 (18) | −0.052 (2) | −0.0420 (19) |
C1 | 0.0419 (15) | 0.0352 (14) | 0.0539 (17) | −0.0043 (12) | −0.0161 (13) | −0.0195 (13) |
C2 | 0.064 (2) | 0.061 (2) | 0.085 (2) | −0.0227 (16) | −0.0069 (17) | −0.0404 (18) |
C3 | 0.0666 (19) | 0.0584 (18) | 0.0560 (18) | −0.0187 (15) | 0.0026 (16) | −0.0369 (16) |
C4 | 0.0469 (16) | 0.0430 (15) | 0.0427 (15) | −0.0020 (13) | −0.0038 (13) | −0.0183 (13) |
C5 | 0.077 (2) | 0.066 (2) | 0.0536 (19) | −0.0144 (17) | 0.0125 (16) | −0.0291 (17) |
C6 | 0.0415 (15) | 0.0413 (15) | 0.0539 (17) | −0.0140 (12) | −0.0044 (13) | −0.0152 (13) |
C7 | 0.0403 (15) | 0.0492 (17) | 0.0573 (18) | −0.0135 (13) | −0.0067 (13) | −0.0194 (14) |
C8 | 0.0487 (16) | 0.0454 (16) | 0.0455 (16) | −0.0062 (13) | −0.0084 (13) | −0.0201 (14) |
C9 | 0.072 (2) | 0.0394 (16) | 0.072 (2) | −0.0161 (15) | −0.0243 (17) | −0.0160 (15) |
C10 | 0.0543 (18) | 0.0466 (17) | 0.066 (2) | −0.0170 (14) | −0.0183 (15) | −0.0175 (15) |
C11 | 0.069 (2) | 0.0484 (18) | 0.062 (2) | −0.0048 (16) | −0.0188 (17) | −0.0271 (16) |
Ni—O1 | 2.0110 (16) | C1—C2 | 1.512 (4) |
Ni—O2 | 2.0238 (18) | C3—C4 | 1.400 (4) |
Ni—N1 | 2.179 (2) | C4—C5 | 1.513 (4) |
O1—C1 | 1.264 (3) | C6—C7 | 1.377 (4) |
O2—C4 | 1.255 (3) | C7—C8 | 1.367 (4) |
N1—C10 | 1.330 (3) | C8—C9 | 1.386 (4) |
N1—C6 | 1.332 (3) | C8—C11 | 1.447 (4) |
N2—C11 | 1.133 (4) | C9—C10 | 1.367 (4) |
C1—C3 | 1.384 (4) | ||
O1—Ni—O2i | 89.81 (7) | C3—C1—C2 | 119.4 (3) |
O1—Ni—O2 | 90.19 (7) | C1—C3—C4 | 126.0 (3) |
O1—Ni—N1i | 89.21 (7) | O2—C4—C3 | 125.5 (3) |
O2—Ni—N1i | 90.35 (8) | O2—C4—C5 | 116.0 (3) |
O1—Ni—N1 | 90.79 (7) | C3—C4—C5 | 118.5 (3) |
O2—Ni—N1 | 89.65 (8) | N1—C6—C7 | 123.7 (3) |
C1—O1—Ni | 126.17 (18) | C8—C7—C6 | 118.6 (3) |
C4—O2—Ni | 125.94 (18) | C7—C8—C9 | 118.6 (3) |
C10—N1—C6 | 116.7 (2) | C7—C8—C11 | 120.1 (3) |
C10—N1—Ni | 121.98 (17) | C9—C8—C11 | 121.3 (3) |
C6—N1—Ni | 121.26 (18) | C10—C9—C8 | 118.7 (3) |
O1—C1—C3 | 125.7 (2) | N1—C10—C9 | 123.7 (3) |
O1—C1—C2 | 114.9 (3) | N2—C11—C8 | 177.7 (4) |
Symmetry code: (i) −x, −y, −z. |
Experimental details
(I) | (II) | |
Crystal data | ||
Chemical formula | [Ni(C5H7O2)2(C6H4N2)2] | [Ni(C5H7O2)2(C6H4N2)2] |
Mr | 465.14 | 465.14 |
Crystal system, space group | Monoclinic, P21/a | Triclinic, P1 |
Temperature (K) | 293 | 293 |
a, b, c (Å) | 7.8295 (6), 19.3334 (18), 8.1244 (10) | 6.2795 (6), 9.912 (1), 10.392 (1) |
α, β, γ (°) | 90, 116.019 (8), 90 | 64.96 (1), 86.441 (8), 73.333 (9) |
V (Å3) | 1105.16 (19) | 560.10 (9) |
Z | 2 | 1 |
Radiation type | Mo Kα | Mo Kα |
µ (mm−1) | 0.91 | 0.90 |
Crystal size (mm) | 0.20 × 0.18 × 0.05 | 0.22 × 0.18 × 0.05 |
Data collection | ||
Diffractometer | Enraf-Nonius CAD4 diffractometer | Enraf-Nonius CAD4 diffractometer |
Absorption correction | ψ-scan (North et al., 1968) | ψ-scan (North et al., 1968) |
Tmin, Tmax | 0.839, 0.956 | 0.855, 0.961 |
No. of measured, independent and observed reflections | 2737, 2529, 1131 (F2 > 2σF2) | 2180, 2059, 1605 [I > 2σ(I)] |
Rint | 0.022 | 0.022 |
(sin θ/λ)max (Å−1) | 0.649 | 0.605 |
Refinement | ||
R[F2 > 2σ(F2)], wR(F2), S | 0.045, 0.115, 0.95 | 0.035, 0.084, 1.06 |
No. of reflections | 2529 | 2059 |
No. of parameters | 144 | 144 |
H-atom treatment | H-atom parameters constrained | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.27, −0.59 | 0.28, −0.26 |
Computer programs: CAD-4 Software (Enraf-Nonius,1989), CAD-4 Software, MolEN (Fair, 1990), SHELXS86 (Sheldrick, 1990), SHELXL97 (Sheldrick, 1997), ZORTEP (Zsolnai, 1995), SHELXL97.
Ni—O1 | 2.009 (2) | N2—C11 | 1.135 (5) |
Ni—O2 | 2.016 (2) | O1—C2 | 1.260 (4) |
Ni—N1 | 2.116 (3) | O2—C4 | 1.258 (4) |
O1—Ni—O2 | 91.86 (10) | O1—C2—C3 | 125.6 (4) |
O1—Ni—N1 | 91.27 (11) | O1—C2—C1 | 115.7 (3) |
O2—Ni—N1 | 90.19 (11) | O2—C4—C3 | 125.1 (4) |
C2—O1—Ni | 124.3 (2) | O2—C4—C5 | 116.1 (4) |
C4—O2—Ni | 124.5 (3) | N2—C11—C7 | 178.5 (5) |
Ni—O1 | 2.0110 (16) | O1—C1 | 1.264 (3) |
Ni—O2 | 2.0238 (18) | O2—C4 | 1.255 (3) |
Ni—N1 | 2.179 (2) | ||
O1—Ni—O2 | 90.19 (7) | C4—O2—Ni | 125.94 (18) |
O1—Ni—N1 | 90.79 (7) | C10—N1—Ni | 121.98 (17) |
O2—Ni—N1 | 89.65 (8) | C6—N1—Ni | 121.26 (18) |
C1—O1—Ni | 126.17 (18) | N2—C11—C8 | 177.7 (4) |
Adducts of NiII acetylacetonate (AcAc) chelate with heterocyclic bases were synthesized with the aim of establishing correlations between the bond energies and other thermochemical parameters (Dunstan, 1998). Among these compounds, of general formula [Ni(AcAc)2·2L], were those with L = 3-cyanopyridine, (I), and 4-cyanopyridine, (II). Based on the ΔrHθ (standard enthalpy of the acid/base reaction) values of these adducts, Dunstan (1998) ascertained that the basicity order was 4-cyanopyridine > 3-cyanopyridine, instead of the reverse, expected, order. It was then postulated that this could be due to the contribution of another kind of interaction such as hydrogen bonding between the N atom of the cyano group and C atoms of the AcAc moiety. In order to study this possibility, crystal structure determinations were undertaken. \sch
In both compounds, the AcAc moiety is planar, to within experimental accuracy, the r.m.s. deviation of the seven atoms being 0.012 and 0.016 Å for (I) and (II), respectively. The NiII atom does not lie in the plane of the AcAc residue but 0.247 (4) and 0.139 (3) Å from it, for (I) and (II), respectively. The NiII atom is sited on a centre of symmetry and is octahedrally bonded to two equatorial AcAc groups and two 3-cyanopyridine [(I)] and two 4-cyanopyridine [(II)] groups, which are axially coordinated in a trans configuration. The Ni—OAcAc distances in (II) of 2.0110 (16) and 2.0238 (18) Å give rise to tetragonal distortion; this is less important in (I), for which the Ni—OAcAc distances are 2.009 (2) and 2.016 (2) Å.
In the solid state no short intramolecular distances were found. The shortest intermolecular distances found for the N atom of the cyano group and C atoms of the AcAc moiety are N2···H1Ai = 2.90 and N2···C1i = 3.832 (6) Å, and N2···H1Ai—C1i = 164° for (I), and N2···H5Cii = 2.65 and N2···C5ii = 3.533 (4) Å, and N2···H5Cii—C5ii = 153° for (II). Moreover, there is an additional interaction in (I) involving a phenyl H-atom, with N2···H9iii = 2.79 and N2···C9iii = 3.503 (6) Å, and N2···C9iii—H9iii = 134° [symmetry codes: (i) 3/2 − x, −1/2 + y, 1 − z; (ii) 1 − x, −1 − y, 1 − z; (iii) −1/2 + x, 1/2 − y, −1 + z].
Whether these interactions are true hydrogen bonds is difficult to assert because, as pointed out by Cotton et al. (1997), `the field is getting muddier and muddier as the definition of a hydrogen bond is relaxed'. In any case, in (II) the N···H distance is marginally shorter than the sum of the van der Waals radii of H and N (2.7 Å).