Transition metal complexes with thiosemicarbazide-based ligands. XV. A square-pyramidal Ni-II complex with an asymmetric coordination of 2,6-diacetylpyridine bis(S-methylisothiosemicarbazone)

The title compound, [diacetylpyridine bis(S-methylisothiosemicarbazonato)]iodonickel(II), [Ni(C13H18N7S2)I], is the first example of a complex involving the N-2 coordination of the isothiosemicarbazide moiety. 2,6-Diacetylpyridine bis(S-methylisothiosemicarbazone), as a potentially pentadentate ligand (N-5), is coordinated as a tetradentate species, whereby one (deprotonated) isothiosemicarbazide moiety is coordinated in the usual way ((NN)-N-1-N-4), but the other (neutral) is bonded via the N-2 atom only, the fourth ligator being the pyridine nitrogen. The difference in coordination mode of the isothiosemicarbazide moiety is reflected in the N-1-N-2 bond lengths of 1.359 (4) and 1.379 (3) Angstrom in the deprotonated and undeprotonated moieties, respectively. The structure contains three fused chelate rings in a 5:5:6 arrangement. The six-membered ring has a non-planar conformation