Self-assembled Transition Metal Coordination Frameworks of ...

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Ni(Il) complexes
Fig. 3.22. Top view and side view of the cationic part of the molecule with
octahedral polyhedra around the Ni(H) centers showing symmetrical nature of la.
Hydrogen atoms are removed for clarity.
The bond parameters (Table 3.7) show that the geometry around Ni(H)
centers are distorted significantly from perfect octahedra. For example considering the
octahedron around the Ni(l) atom, the mean plane of the bicyclic chelate ring Ni(l),
N(l), C(5), C(6), N(3), N(4), C(12), S(2) {having a maximum deviation of 0.020(11)
A for N(l) atom} makes a dihedral angle of 86.8(2)° with that of its counterpart
chelate ring defined by Ni(l), N(25), C(74), C(75), N(27), N(28), C(81), S(1) {having
a maximum deviation of -0.125(13) A for the C(74) atom}. The bond lengths Ni­
Nmmcmmc, Ni-Npy, and Ni-S around the Ni(l) atom increase in that order as in similar
compounds [8,16] and as in mononuclear Ni(H) octahedral thiosemicarbazone
complexes [25, 44-47]. Also, the trans angles N(l)-Ni(l)—S(2), N(25)-Ni(l)-S(1) and
N(3)-Ni(l)-N(27) are l6l.9(3)°, l6l.3(3)° and 175.0(4)° respectively. These factors
suggest considerable distortion from a perfect octahedral geometry around the Ni(l)
center.
The C-S bond lengths of ~1.73 A are within the normal ranges of a C-S
single bond. The hydrogen atoms were located at N(5), N(l2), N(20) and N(28). The
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