Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536807037129/hg2264sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S1600536807037129/hg2264IIIsup2.hkl |
CCDC reference: 180636
To a solution of nickel(II) chloride hexahydrate (0.03 g; 1.25 x 10 -4 mol) in boiling methanol (20 ml), conc. HCl (ca 0.3 ml) was added. The solution was mixed with a hot solution of the Schiff base, 2,6-diacetylpyridinebis(S-methyldithiocarbazonate, (I)) (0.09 g; 2.5 x 10 -4 mol) in methanol (50 ml) and the mixture was heated on a water bath for about one minute. On standing, the reaction mixture deposited crystals of the complex which were filtered off, washed with methanol and dried in a desiccator over anhydrous silica gel. Hydrolysis of (I) to (II) during the reaction was confirmed by isolation of its NiII complex (III).
All H atoms were treated as riding with C—H distances ranging from 0.93 to 0.96 Å and Uiso(H) values equal to 1.5 (methyl H atoms) or 1.2 (all other atoms) times Ueq of the parent atom. Only a unique (octant) data set was measured for the orthorhombic system so the Rint value is undetermined. Also the Flack parameter is only nominal given the lack of Friedel pairs in the data set.
The potentially pentadendate Schiff base ligand (I) and its close relatives have been shown to favour pentagonal bipyramidal structures when complexed with metals such Sn(IV) (Akbar Ali et al., 2004), Zn(II) and Cd(II) (Akbar Ali, Mirza, Voo et al., 2003). In the synthesis of (I) it has been reported that the intermediate one-armed analogue (II) is also a product of the condensation reaction between 2,6-diacetylpyridine and S-methyldithiocarbate (Akbar Ali, Mirza, Keng & Butcher, 2003). The Pd(II) complex of (II) was structurally characterized. Herein we report the crystal structure of the bis-ligated six-coordinate NiII complex (III).
The structure of (III) reveals a distorted octahedral coordination geometry (Fig. 1). Each ligand deprotonates at N1a/b and the C1a/b-N1/a/b bonds approach double bond order due to the preferred ene-thiolate form of the coordinated monoanionic ligand (Table 2). The ligands each bind as a tridentate N,N,S chelate and the planar nature of the ligand enforces a meridional coordination mode. The shortest bond lengths are the central Ni—N bonds as expected. A point of interest is the rather long Ni—N3a/b bonds in comparison with the homologous complex (IV) (av. 2.12 Å) which lacks any substituents on the 6-positions of its pyridyl rings (Su et al., 1998). In this case the Ni—N bond lengths are more than 0.06 Å longer than found in the structure of (IV). Steric interactions between the non-coordinating acetyl groups and the adjacent ligand result in this bond elongation. The structure of the 6-methyl substituted analog (V) also exhibits a similar lengthening of the Ni—Npyr coordinate bonds (Akbar Ali et al., 1997). It is also notable that these coordinate bond distortions are localized at the pyridyl groups as the remaining Ni—N and Ni—S coordinate bonds are the same within experimental error as those reported for (IV).
In conclusion, the absence of a second chelating arm in the ligand (II) leads to a preferred bis-tridentate coordination mode in complex with NiII and the 6-acetyl substituents on the pyridyl rings play a role in lengthening the Ni—Npyr bonds substantially.
For related literature, see: Akbar Ali, Mahbub-ul-Haque Majumder, Butcher, Jasinski & Jasinski (1997); Akbar Ali, Mirza, Keng & Butcher (2003); Akbar Ali, Mirza, Tan, Wei & Bernhardt (2004); Akbar Ali, Mirza, Voo, Tan & Bernhardt (2003); Su et al. (1998).
Data collection: CAD-4 EXPRESS (Enraf–Nonius, 1994); cell refinement: CAD-4 EXPRESS; data reduction: XCAD4 (Harms & Wocadlo, 1995); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997); software used to prepare material for publication: WinGX (Version 1.64.02; Farrugia, 1999).
[Ni(C11H12N3OS2)2] | F(000) = 1224 |
Mr = 591.42 | Dx = 1.51 Mg m−3 |
Orthorhombic, P212121 | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: P 2ac 2ab | Cell parameters from 25 reflections |
a = 10.6343 (8) Å | θ = 11.5–13.5° |
b = 10.8217 (7) Å | µ = 1.10 mm−1 |
c = 22.603 (2) Å | T = 293 K |
V = 2601.2 (3) Å3 | Prism, brown |
Z = 4 | 0.6 × 0.6 × 0.3 mm |
Enraf–Nonius CAD-4 diffractometer | 2197 reflections with I > 2σ(I) |
Radiation source: Enraf–Nonius FR590 | Rint = 0 |
Graphite monochromator | θmax = 25.0°, θmin = 1.8° |
non–profiled ω/2θ scans | h = 0→12 |
Absorption correction: ψ scan (North et al., 1968) | k = 0→12 |
Tmin = 0.558, Tmax = 0.734 | l = 0→26 |
2601 measured reflections | 3 standard reflections every 120 min |
2601 independent reflections | intensity decay: 1% |
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)] = 0.027 | H-atom parameters constrained |
wR(F2) = 0.075 | w = 1/[σ2(Fo2) + (0.0488P)2 + 0.1306P] where P = (Fo2 + 2Fc2)/3 |
S = 1.05 | (Δ/σ)max < 0.001 |
2601 reflections | Δρmax = 0.36 e Å−3 |
316 parameters | Δρmin = −0.24 e Å−3 |
0 restraints | Absolute structure: Flack (1983), with how many Friedel pairs? |
Primary atom site location: structure-invariant direct methods | Absolute structure parameter: 0.032 (17) |
[Ni(C11H12N3OS2)2] | V = 2601.2 (3) Å3 |
Mr = 591.42 | Z = 4 |
Orthorhombic, P212121 | Mo Kα radiation |
a = 10.6343 (8) Å | µ = 1.10 mm−1 |
b = 10.8217 (7) Å | T = 293 K |
c = 22.603 (2) Å | 0.6 × 0.6 × 0.3 mm |
Enraf–Nonius CAD-4 diffractometer | 2197 reflections with I > 2σ(I) |
Absorption correction: ψ scan (North et al., 1968) | Rint = 0 |
Tmin = 0.558, Tmax = 0.734 | 3 standard reflections every 120 min |
2601 measured reflections | intensity decay: 1% |
2601 independent reflections |
R[F2 > 2σ(F2)] = 0.027 | H-atom parameters constrained |
wR(F2) = 0.075 | Δρmax = 0.36 e Å−3 |
S = 1.05 | Δρmin = −0.24 e Å−3 |
2601 reflections | Absolute structure: Flack (1983), with how many Friedel pairs? |
316 parameters | Absolute structure parameter: 0.032 (17) |
0 restraints |
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 | ||
Ni1 | 0.73584 (4) | 0.93441 (4) | 0.12063 (2) | 0.03305 (14) | |
C1A | 0.7000 (4) | 0.7464 (4) | 0.21782 (18) | 0.0388 (9) | |
C1B | 0.5642 (4) | 0.9426 (4) | 0.01415 (17) | 0.0409 (9) | |
C2A | 0.6984 (6) | 0.6758 (5) | 0.33646 (19) | 0.0660 (15) | |
H2A1 | 0.6993 | 0.6094 | 0.3646 | 0.099* | |
H2A2 | 0.6235 | 0.7241 | 0.3417 | 0.099* | |
H2A3 | 0.7709 | 0.7273 | 0.3424 | 0.099* | |
C2B | 0.5101 (5) | 0.9472 (6) | −0.10626 (19) | 0.0710 (15) | |
H2B1 | 0.447 | 0.9499 | −0.1366 | 0.107* | |
H2B2 | 0.5595 | 0.8735 | −0.1107 | 0.107* | |
H2B3 | 0.5636 | 1.0183 | −0.1096 | 0.107* | |
C3A | 0.6694 (4) | 1.0590 (4) | 0.22846 (16) | 0.0376 (9) | |
C3B | 0.8810 (4) | 0.9067 (4) | 0.01403 (19) | 0.0424 (10) | |
C4A | 0.6422 (5) | 1.0822 (4) | 0.29212 (17) | 0.0531 (11) | |
H4A1 | 0.6389 | 1.0049 | 0.3129 | 0.08* | |
H4A2 | 0.5629 | 1.1237 | 0.2958 | 0.08* | |
H4A3 | 0.7074 | 1.1329 | 0.3087 | 0.08* | |
C4B | 0.9165 (5) | 0.8986 (5) | −0.05007 (18) | 0.0612 (14) | |
H4B1 | 0.8424 | 0.9058 | −0.074 | 0.092* | |
H4B2 | 0.9563 | 0.8205 | −0.0576 | 0.092* | |
H4B3 | 0.9737 | 0.9643 | −0.0596 | 0.092* | |
C5A | 0.6787 (4) | 1.1619 (4) | 0.18649 (19) | 0.0380 (9) | |
C5B | 0.9791 (4) | 0.8978 (4) | 0.06058 (19) | 0.0400 (10) | |
C6A | 0.6311 (4) | 1.2788 (4) | 0.1985 (2) | 0.0475 (11) | |
H6A | 0.5937 | 1.2954 | 0.2349 | 0.057* | |
C6B | 1.1035 (4) | 0.8744 (5) | 0.0466 (2) | 0.0545 (12) | |
H6B | 1.1279 | 0.8658 | 0.0073 | 0.065* | |
C7A | 0.6397 (5) | 1.3698 (4) | 0.1562 (2) | 0.0573 (12) | |
H7A | 0.6052 | 1.4474 | 0.1631 | 0.069* | |
C7B | 1.1902 (4) | 0.8640 (5) | 0.0910 (2) | 0.0605 (13) | |
H7B | 1.2741 | 0.8479 | 0.0825 | 0.073* | |
C8A | 0.6995 (5) | 1.3451 (4) | 0.1041 (2) | 0.0542 (12) | |
H8A | 0.7058 | 1.4055 | 0.0749 | 0.065* | |
C8B | 1.1505 (4) | 0.8780 (4) | 0.1483 (2) | 0.0578 (13) | |
H8B | 1.2074 | 0.8697 | 0.1793 | 0.069* | |
C9A | 0.7504 (4) | 1.2290 (4) | 0.09532 (18) | 0.0442 (9) | |
C9B | 1.0268 (4) | 0.9041 (4) | 0.15966 (19) | 0.0432 (10) | |
C10A | 0.8309 (6) | 1.2056 (4) | 0.0410 (2) | 0.0630 (14) | |
C10B | 0.9866 (4) | 0.9276 (4) | 0.22341 (19) | 0.0481 (10) | |
C11A | 0.7768 (8) | 1.2393 (6) | −0.0167 (2) | 0.103 (3) | |
H11D | 0.8364 | 1.2215 | −0.0475 | 0.155* | |
H11E | 0.7571 | 1.3258 | −0.017 | 0.155* | |
H11F | 0.7014 | 1.1924 | −0.0233 | 0.155* | |
C11B | 1.0123 (6) | 0.8259 (5) | 0.2656 (2) | 0.0741 (16) | |
H11A | 0.9843 | 0.8494 | 0.3044 | 0.111* | |
H11B | 1.101 | 0.8094 | 0.2666 | 0.111* | |
H11C | 0.9683 | 0.7529 | 0.2532 | 0.111* | |
N1A | 0.6847 (3) | 0.8516 (3) | 0.24452 (15) | 0.0412 (8) | |
N1B | 0.6739 (3) | 0.9282 (3) | −0.00883 (13) | 0.0403 (7) | |
N2A | 0.6903 (3) | 0.9504 (3) | 0.20621 (13) | 0.0355 (7) | |
N2B | 0.7690 (3) | 0.9214 (3) | 0.03321 (13) | 0.0361 (7) | |
N3A | 0.7383 (3) | 1.1368 (3) | 0.13456 (13) | 0.0353 (7) | |
N3B | 0.9405 (3) | 0.9159 (3) | 0.11689 (15) | 0.0378 (7) | |
S1A | 0.71898 (12) | 0.71710 (10) | 0.14389 (5) | 0.0465 (3) | |
S1B | 0.52284 (9) | 0.95535 (12) | 0.08710 (4) | 0.0471 (3) | |
S2A | 0.70145 (14) | 0.61389 (11) | 0.26300 (5) | 0.0592 (3) | |
S2B | 0.43594 (11) | 0.94696 (14) | −0.03511 (5) | 0.0573 (3) | |
O1A | 0.9365 (4) | 1.1685 (4) | 0.04757 (19) | 0.0833 (13) | |
O1B | 0.9389 (3) | 1.0233 (3) | 0.23694 (15) | 0.0592 (9) |
U11 | U22 | U33 | U12 | U13 | U23 | |
Ni1 | 0.0334 (2) | 0.0345 (2) | 0.0312 (2) | −0.0014 (2) | 0.0013 (2) | −0.0021 (2) |
C1A | 0.036 (2) | 0.037 (2) | 0.044 (2) | −0.0014 (18) | −0.0042 (18) | 0.0084 (18) |
C1B | 0.046 (2) | 0.033 (2) | 0.044 (2) | 0.001 (2) | −0.0068 (18) | −0.003 (2) |
C2A | 0.092 (4) | 0.063 (3) | 0.043 (3) | −0.003 (3) | 0.003 (3) | 0.012 (2) |
C2B | 0.075 (3) | 0.096 (4) | 0.042 (2) | −0.009 (3) | −0.010 (2) | 0.009 (3) |
C3A | 0.0350 (19) | 0.040 (2) | 0.0376 (19) | −0.003 (2) | 0.0012 (16) | −0.0049 (19) |
C3B | 0.046 (2) | 0.038 (2) | 0.044 (2) | −0.0020 (19) | 0.0095 (19) | −0.0023 (19) |
C4A | 0.068 (3) | 0.052 (3) | 0.039 (2) | −0.004 (3) | 0.007 (2) | −0.007 (2) |
C4B | 0.057 (3) | 0.084 (4) | 0.043 (2) | 0.004 (3) | 0.015 (2) | −0.004 (2) |
C5A | 0.035 (2) | 0.034 (2) | 0.045 (2) | −0.0054 (17) | −0.006 (2) | −0.0063 (18) |
C5B | 0.038 (2) | 0.033 (2) | 0.049 (2) | −0.0027 (17) | 0.0031 (19) | −0.0017 (18) |
C6A | 0.049 (3) | 0.039 (2) | 0.054 (3) | 0.002 (2) | 0.006 (2) | −0.013 (2) |
C6B | 0.037 (2) | 0.053 (3) | 0.073 (3) | −0.004 (2) | 0.012 (2) | −0.006 (3) |
C7A | 0.061 (3) | 0.032 (2) | 0.079 (3) | 0.005 (2) | 0.002 (3) | −0.004 (2) |
C7B | 0.028 (2) | 0.058 (3) | 0.095 (4) | 0.002 (2) | 0.004 (2) | −0.011 (3) |
C8A | 0.062 (3) | 0.033 (2) | 0.067 (3) | 0.000 (2) | 0.005 (2) | 0.010 (2) |
C8B | 0.034 (2) | 0.053 (3) | 0.086 (3) | 0.002 (2) | −0.016 (2) | −0.010 (3) |
C9A | 0.045 (2) | 0.040 (2) | 0.048 (2) | −0.005 (2) | −0.001 (2) | 0.0049 (18) |
C9B | 0.038 (2) | 0.034 (2) | 0.058 (3) | −0.0058 (18) | −0.006 (2) | −0.0061 (19) |
C10A | 0.097 (4) | 0.033 (2) | 0.060 (3) | −0.009 (3) | 0.023 (3) | 0.007 (2) |
C10B | 0.039 (2) | 0.051 (3) | 0.054 (2) | −0.004 (2) | −0.0140 (19) | −0.011 (2) |
C11A | 0.172 (8) | 0.086 (4) | 0.052 (3) | −0.007 (5) | 0.020 (4) | 0.009 (3) |
C11B | 0.083 (4) | 0.074 (4) | 0.065 (4) | 0.011 (3) | −0.013 (3) | 0.006 (3) |
N1A | 0.0463 (19) | 0.0378 (19) | 0.0394 (18) | −0.0045 (16) | 0.0008 (16) | 0.0074 (16) |
N1B | 0.0421 (18) | 0.0453 (19) | 0.0336 (16) | 0.0015 (18) | −0.0038 (14) | 0.0003 (17) |
N2A | 0.0364 (17) | 0.0354 (18) | 0.0347 (16) | −0.0019 (15) | −0.0012 (13) | 0.0003 (14) |
N2B | 0.0364 (16) | 0.0369 (17) | 0.0351 (15) | 0.0005 (17) | 0.0048 (15) | −0.0003 (14) |
N3A | 0.0354 (17) | 0.0336 (16) | 0.0367 (17) | 0.0007 (15) | 0.0030 (15) | 0.0003 (13) |
N3B | 0.0317 (15) | 0.0347 (18) | 0.0470 (18) | −0.0014 (14) | −0.0029 (15) | −0.0028 (17) |
S1A | 0.0627 (7) | 0.0349 (5) | 0.0417 (5) | −0.0032 (5) | 0.0036 (5) | −0.0027 (4) |
S1B | 0.0327 (5) | 0.0656 (8) | 0.0428 (5) | −0.0014 (5) | 0.0003 (4) | −0.0091 (6) |
S2A | 0.0878 (9) | 0.0398 (6) | 0.0500 (7) | −0.0036 (6) | −0.0048 (6) | 0.0104 (5) |
S2B | 0.0481 (6) | 0.0739 (9) | 0.0499 (6) | 0.0051 (7) | −0.0147 (5) | −0.0001 (7) |
O1A | 0.086 (3) | 0.065 (3) | 0.098 (3) | 0.009 (2) | 0.048 (3) | 0.013 (2) |
O1B | 0.058 (2) | 0.0513 (19) | 0.069 (2) | 0.0038 (17) | −0.0120 (17) | −0.0159 (17) |
Ni1—N2A | 2.002 (3) | C5A—N3A | 1.361 (5) |
Ni1—N2B | 2.012 (3) | C5A—C6A | 1.390 (6) |
Ni1—N3B | 2.188 (3) | C5B—N3B | 1.351 (5) |
Ni1—N3A | 2.213 (3) | C5B—C6B | 1.383 (6) |
Ni1—S1B | 2.399 (1) | C6A—C7A | 1.375 (6) |
Ni1—S1A | 2.416 (1) | C6A—H6A | 0.93 |
C1A—N1A | 1.299 (5) | C6B—C7B | 1.368 (7) |
C1A—S1A | 1.713 (4) | C6B—H6B | 0.93 |
C1A—S2A | 1.760 (4) | C7A—C8A | 1.366 (6) |
C1B—N1B | 1.286 (5) | C7A—H7A | 0.93 |
C1B—S1B | 1.712 (4) | C7B—C8B | 1.370 (7) |
C1B—S2B | 1.761 (4) | C7B—H7B | 0.93 |
C2A—S2A | 1.791 (5) | C8A—C9A | 1.382 (6) |
C2A—H2A1 | 0.96 | C8A—H8A | 0.93 |
C2A—H2A2 | 0.96 | C8B—C9B | 1.371 (6) |
C2A—H2A3 | 0.96 | C8B—H8B | 0.93 |
C2B—S2B | 1.791 (5) | C9A—N3A | 1.342 (5) |
C2B—H2B1 | 0.96 | C9A—C10A | 1.518 (7) |
C2B—H2B2 | 0.96 | C9B—N3B | 1.338 (5) |
C2B—H2B3 | 0.96 | C9B—C10B | 1.524 (6) |
C3A—N2A | 1.297 (5) | C10A—O1A | 1.201 (7) |
C3A—C5A | 1.466 (6) | C10A—C11A | 1.473 (8) |
C3A—C4A | 1.489 (5) | C10B—O1B | 1.193 (5) |
C3B—N2B | 1.277 (5) | C10B—C11B | 1.482 (6) |
C3B—C5B | 1.485 (6) | C11A—H11D | 0.96 |
C3B—C4B | 1.500 (5) | C11A—H11E | 0.96 |
C4A—H4A1 | 0.96 | C11A—H11F | 0.96 |
C4A—H4A2 | 0.96 | C11B—H11A | 0.96 |
C4A—H4A3 | 0.96 | C11B—H11B | 0.96 |
C4B—H4B1 | 0.96 | C11B—H11C | 0.96 |
C4B—H4B2 | 0.96 | N1A—N2A | 1.377 (4) |
C4B—H4B3 | 0.96 | N1B—N2B | 1.390 (4) |
N2A—Ni1—N2B | 176.0 (1) | C5A—C6A—H6A | 120.3 |
N2A—Ni1—N3B | 106.6 (1) | C7B—C6B—C5B | 119.4 (5) |
N2B—Ni1—N3B | 77.4 (1) | C7B—C6B—H6B | 120.3 |
N2A—Ni1—N3A | 77.3 (1) | C5B—C6B—H6B | 120.3 |
N2B—Ni1—N3A | 102.0 (1) | C8A—C7A—C6A | 119.4 (4) |
N3B—Ni1—N3A | 94.8 (1) | C8A—C7A—H7A | 120.3 |
N2A—Ni1—S1B | 93.92 (9) | C6A—C7A—H7A | 120.3 |
N2B—Ni1—S1B | 82.07 (9) | C6B—C7B—C8B | 118.5 (4) |
N3B—Ni1—S1B | 159.4 (1) | C6B—C7B—H7B | 120.7 |
N3A—Ni1—S1B | 87.85 (9) | C8B—C7B—H7B | 120.7 |
N2A—Ni1—S1A | 81.7 (1) | C7A—C8A—C9A | 118.9 (4) |
N2B—Ni1—S1A | 99.12 (9) | C7A—C8A—H8A | 120.5 |
N3B—Ni1—S1A | 89.61 (9) | C9A—C8A—H8A | 120.5 |
N3A—Ni1—S1A | 158.93 (8) | C7B—C8B—C9B | 119.7 (4) |
S1B—Ni1—S1A | 95.20 (5) | C7B—C8B—H8B | 120.2 |
N1A—C1A—S1A | 129.0 (3) | C9B—C8B—H8B | 120.2 |
N1A—C1A—S2A | 116.5 (3) | N3A—C9A—C8A | 123.0 (4) |
S1A—C1A—S2A | 114.5 (2) | N3A—C9A—C10A | 117.7 (4) |
N1B—C1B—S1B | 129.2 (3) | C8A—C9A—C10A | 119.3 (4) |
N1B—C1B—S2B | 116.8 (3) | N3B—C9B—C8B | 122.8 (4) |
S1B—C1B—S2B | 114.1 (2) | N3B—C9B—C10B | 118.4 (3) |
S2A—C2A—H2A1 | 109.5 | C8B—C9B—C10B | 118.7 (4) |
S2A—C2A—H2A2 | 109.5 | O1A—C10A—C11A | 123.9 (6) |
H2A1—C2A—H2A2 | 109.5 | O1A—C10A—C9A | 118.9 (5) |
S2A—C2A—H2A3 | 109.5 | C11A—C10A—C9A | 117.0 (5) |
H2A1—C2A—H2A3 | 109.5 | O1B—C10B—C11B | 123.9 (4) |
H2A2—C2A—H2A3 | 109.5 | O1B—C10B—C9B | 120.4 (4) |
S2B—C2B—H2B1 | 109.5 | C11B—C10B—C9B | 115.7 (4) |
S2B—C2B—H2B2 | 109.5 | C10A—C11A—H11D | 109.5 |
H2B1—C2B—H2B2 | 109.5 | C10A—C11A—H11E | 109.5 |
S2B—C2B—H2B3 | 109.5 | H11D—C11A—H11E | 109.5 |
H2B1—C2B—H2B3 | 109.5 | C10A—C11A—H11F | 109.5 |
H2B2—C2B—H2B3 | 109.5 | H11D—C11A—H11F | 109.5 |
N2A—C3A—C5A | 115.2 (3) | H11E—C11A—H11F | 109.5 |
N2A—C3A—C4A | 124.1 (4) | C10B—C11B—H11A | 109.5 |
C5A—C3A—C4A | 120.7 (4) | C10B—C11B—H11B | 109.5 |
N2B—C3B—C5B | 115.0 (4) | H11A—C11B—H11B | 109.5 |
N2B—C3B—C4B | 124.8 (4) | C10B—C11B—H11C | 109.5 |
C5B—C3B—C4B | 120.2 (4) | H11A—C11B—H11C | 109.5 |
C3A—C4A—H4A1 | 109.5 | H11B—C11B—H11C | 109.5 |
C3A—C4A—H4A2 | 109.5 | C1A—N1A—N2A | 112.5 (3) |
H4A1—C4A—H4A2 | 109.5 | C1B—N1B—N2B | 113.0 (3) |
C3A—C4A—H4A3 | 109.5 | C3A—N2A—N1A | 116.9 (3) |
H4A1—C4A—H4A3 | 109.5 | C3A—N2A—Ni1 | 119.6 (3) |
H4A2—C4A—H4A3 | 109.5 | N1A—N2A—Ni1 | 123.4 (2) |
C3B—C4B—H4B1 | 109.5 | C3B—N2B—N1B | 117.0 (3) |
C3B—C4B—H4B2 | 109.5 | C3B—N2B—Ni1 | 120.4 (3) |
H4B1—C4B—H4B2 | 109.5 | N1B—N2B—Ni1 | 122.7 (2) |
C3B—C4B—H4B3 | 109.5 | C9A—N3A—C5A | 117.8 (3) |
H4B1—C4B—H4B3 | 109.5 | C9A—N3A—Ni1 | 130.1 (3) |
H4B2—C4B—H4B3 | 109.5 | C5A—N3A—Ni1 | 108.4 (2) |
N3A—C5A—C6A | 121.3 (4) | C9B—N3B—C5B | 117.3 (3) |
N3A—C5A—C3A | 115.9 (3) | C9B—N3B—Ni1 | 131.5 (3) |
C6A—C5A—C3A | 122.7 (4) | C5B—N3B—Ni1 | 110.6 (3) |
N3B—C5B—C6B | 122.2 (4) | C1A—S1A—Ni1 | 92.36 (14) |
N3B—C5B—C3B | 116.4 (3) | C1B—S1B—Ni1 | 93.10 (14) |
C6B—C5B—C3B | 121.4 (4) | C1A—S2A—C2A | 103.5 (2) |
C7A—C6A—C5A | 119.4 (4) | C1B—S2B—C2B | 103.1 (2) |
C7A—C6A—H6A | 120.3 |
Experimental details
Crystal data | |
Chemical formula | [Ni(C11H12N3OS2)2] |
Mr | 591.42 |
Crystal system, space group | Orthorhombic, P212121 |
Temperature (K) | 293 |
a, b, c (Å) | 10.6343 (8), 10.8217 (7), 22.603 (2) |
V (Å3) | 2601.2 (3) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 1.10 |
Crystal size (mm) | 0.6 × 0.6 × 0.3 |
Data collection | |
Diffractometer | Enraf–Nonius CAD-4 |
Absorption correction | ψ scan (North et al., 1968) |
Tmin, Tmax | 0.558, 0.734 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 2601, 2601, 2197 |
Rint | 0 |
(sin θ/λ)max (Å−1) | 0.594 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.027, 0.075, 1.05 |
No. of reflections | 2601 |
No. of parameters | 316 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.36, −0.24 |
Absolute structure | Flack (1983), with how many Friedel pairs? |
Absolute structure parameter | 0.032 (17) |
Computer programs: CAD-4 EXPRESS (Enraf–Nonius, 1994), CAD-4 EXPRESS, XCAD4 (Harms & Wocadlo, 1995), SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), ORTEP-3 for Windows (Farrugia, 1997), WinGX (Version 1.64.02; Farrugia, 1999).
The potentially pentadendate Schiff base ligand (I) and its close relatives have been shown to favour pentagonal bipyramidal structures when complexed with metals such Sn(IV) (Akbar Ali et al., 2004), Zn(II) and Cd(II) (Akbar Ali, Mirza, Voo et al., 2003). In the synthesis of (I) it has been reported that the intermediate one-armed analogue (II) is also a product of the condensation reaction between 2,6-diacetylpyridine and S-methyldithiocarbate (Akbar Ali, Mirza, Keng & Butcher, 2003). The Pd(II) complex of (II) was structurally characterized. Herein we report the crystal structure of the bis-ligated six-coordinate NiII complex (III).
The structure of (III) reveals a distorted octahedral coordination geometry (Fig. 1). Each ligand deprotonates at N1a/b and the C1a/b-N1/a/b bonds approach double bond order due to the preferred ene-thiolate form of the coordinated monoanionic ligand (Table 2). The ligands each bind as a tridentate N,N,S chelate and the planar nature of the ligand enforces a meridional coordination mode. The shortest bond lengths are the central Ni—N bonds as expected. A point of interest is the rather long Ni—N3a/b bonds in comparison with the homologous complex (IV) (av. 2.12 Å) which lacks any substituents on the 6-positions of its pyridyl rings (Su et al., 1998). In this case the Ni—N bond lengths are more than 0.06 Å longer than found in the structure of (IV). Steric interactions between the non-coordinating acetyl groups and the adjacent ligand result in this bond elongation. The structure of the 6-methyl substituted analog (V) also exhibits a similar lengthening of the Ni—Npyr coordinate bonds (Akbar Ali et al., 1997). It is also notable that these coordinate bond distortions are localized at the pyridyl groups as the remaining Ni—N and Ni—S coordinate bonds are the same within experimental error as those reported for (IV).
In conclusion, the absence of a second chelating arm in the ligand (II) leads to a preferred bis-tridentate coordination mode in complex with NiII and the 6-acetyl substituents on the pyridyl rings play a role in lengthening the Ni—Npyr bonds substantially.