Synthesis and molecular structure of tricarbonyl(diphenyl ditelluride)diiodoiron (CO)3FeI2(Te2Ph 2) and tricarbonyldiiodo[iodo(phenyl)tellurido]iron (CO) 3FeI2(PhTeI): First example of the coordination of unstable PhTeI to the transition metal atom

A reaction of the tetramer [PhTeI]4 with Fe(CO)5 gave the monomeric complex (CO)3FeI2(Ph2Te2) (I) containing a diphenyl ditelluride molecule linked with cis-tricarbonyldiiodoiron. According to X-ray diffraction data, the Fe-Te distance in complex I (2.5724(6) Å) is appreciably shorter than the sum of the covalent Fe and Te radii and the Te-Te bond (2.7705(5) Å) is only slightly longer than that in free Ph2Te2 (2.705(1) Å). In the reaction of Fe(CO)5 with PhTeI3, a complex with PhTeI as a ligand to the transition metal atom was obtained for the first time. Unlike free PhTeI, the resulting complex (CO)3FeI2(PhTeI) (II) is stable in air at room temperature for several days. According to X-ray diffraction data, the ligand PhTeI (Te-C 2.126(4) Å, Te-I(3) 2.7548(5) Å) is stabilized by the coordination of tellurium to both the iron (Te-Fe 2.5451(6) Å) and iodine atoms (Te(1)-I(1) 3.1634(5) Å). The latter coordination probably involves the vacant d orbital of tellurium and the lone electron pair on the iodide ligand.