Unusual Formation of the Paramagnetic Complex (η4-C4Me4)CoI2(PhTeI) and Specific Features of Its Electronic, Molecular, and Crystal Structures.

The 18-electron (η4-C4Me4)Co(CO)2TeI2Ph compound noticeably decomposes upon prolonged storage and also unusually transforms into the 17-electron (η4-C4Me4)CoI2(PhTeI) complex (I). The X-ray diffraction study of the molecular and crystal structures of complex I (CIF file CCDC no. 1991837) reveals interesting analogies with the molecular structures of the known metal complexes containing organotellurium halide ligands and with the crystal packing of the related one-component crystals of (η4-C4Me4)Co(СО)2TeI2Ph and (η4-C4Me4)Co(СО)2I and two-component crystals of (η4-C4Me4)Co(СО)2I–1,4-C6H4I2. An analysis of the crystal packing of molecules of complex I elucidates a new supramolecular synthone I···(η4-C4Me4) determining the structural motifs of self-assembly in complex I and related compounds (η4-C4Me4)Co(CO)2I, (η4-C4Me4)Co(CO)2I···1,4-C6H4I2, and (η4-C4Me4)Co(CO)2TeI2Ph. The EPR study of compound I shows that cobalt exists in the low-spin state with the total spin S = 1/2. [ABSTRACT FROM AUTHOR]