Unusual Formation of the Paramagnetic Complex (η 4 -C 4 Me 4 )CoI 2 (PhTeI) and Specific Features of Its Electronic, Molecular, and Crystal Structures

The 18-electron (η 4 -C 4 Me 4 )Co(CO) 2 TeI 2 Ph compound noticeably decomposes upon prolonged storage and also unusually transforms into the 17-electron (η 4 -C 4 Me 4 )CoI 2 (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 (η 4 -C 4 Me 4 )Co(СО) 2 TeI 2 Ph and (η 4 -C 4 Me 4 )Co(СО) 2 I and two-component crystals of (η 4 -C 4 Me 4 )Co(СО) 2 I–1,4-C 6 H 4 I 2 . An analysis of the crystal packing of molecules of complex I elucidates a new supramolecular synthone I ···(η 4 -C 4 Me 4 ) determining the structural motifs of self-assembly in complex I and related compounds (η 4 -C 4 Me 4 )Co(CO) 2 I, (η 4 -C 4 Me 4 )Co(CO) 2 I···1,4-C 6 H 4 I 2 , and (η 4 -C 4 Me 4 )Co(CO) 2 TeI 2 Ph. The EPR study of compound I shows that cobalt exists in the low-spin state with the total spin S = 1/2.