A new example of intramolecular C—H⋅⋅⋅Ni anagostic interactions

Abstract

The reaction of Ni^II acetate tetrahydrate with 4-methyl-2-(1,2,3,4-tetrahydronaphthalen-1-ylidene)hydrazinecarbothioamide in a 2:1 molar ratio and recrystallization from dimethylformamide yielded the title compound, [Ni(C₁₂H₁₄N₃S)₂]&sdot;C₃H₇NO. The ligands act as monoanionic κ²<em>N</em>¹,<em>S</em>-donors, forming five-membered metallarings. The Ni^II ion is fourfold coordinated in a distorted square-planar <em>cis</em>-configuration, which is rather uncommon for monothiosemicarbazone complexes. Intramolecular H&sdot;&sdot;&sdot;Ni <em>trans</em>-interactions are observed [H&sdot;&sdot;&sdot;Ni distances are 2.50 and 2.57 Å] and thus anagostic interactions can be suggested. The Hirshfeld surface analysis indicates that the major contributions for the crystal packing are H&sdot;&sdot;&sdot;H (66.6%), H&sdot;&sdot;&sdot;S (12.3%) and H&sdot;&sdot;&sdot;C (10.9%) interactions. In the crystal, the complex molecules are linked by dimethylformamide solvent molecules through N—H&sdot;&sdot;&sdot;O interactions into one-dimensional hydrogen-bonded polymers along [010].