Synthesis and molecular structure of new families of iridium(III)-Cp★ and rhodium(III)-Cp★ complexes derived from 1,2-dicyanoethene-1, 2-dithiolate 2,2′-biimidazole or 2,2′-bithiazole. Single crystal structures of [(η 5-Me 5C 5)Ir(biimH 2)Cl]Cl and [(η 5-Me 5C 5)Rh(dcdt)

Abstract

Reaction of [(η 5-Me 5C 5)MCl 2] 2 (M  Ir or Rh) with 1,2-dicyanoethene-1,2-dithiolate (dcdt 2−), 2,2′-biimidazole (biimH 2), or 2,2′-bithiazole (bith) affords various d 6 complexes in high yield. Pentacoordinate compounds such as [(η 5-Me 5C 5)M(dcdt)] (M  Ir or Rh) and hexacoordinate complexes of the type [(η 5-Me 5C 5)M(biimH 2)Cl]Cl, (M  Ir or Rh) or [(η 5-Me 5C 5)Ir(bith)Cl]Cl have been synthesized and characterized. [(η 5-Me 5C 5)Rh (dcdt)] crystallizes in the orthorhombic space group C222 1 with unit cell parameters a = 11.972 (3), b = 15.072 (4), c = 16.456 (5) Å. Refinement of 859 observed reflections led to the final values of R = 2.31 and R w = 3.46%. [(η 5-Me 5C 5)Ir(biimH 2)Cl]Cl crystallizes in the orthorhombic space group P2 12 12 1 with unit cell parameters a = 14.610 (4), b = 14.556 (6), c = 8654 (3) Å. Refinement of 1630 observed reflections led to a value of R = 186 and R w = 2.65%. The biimH 2-iridium complex exhibits a characteristic three-legged “piano-stool” arrangement and the dcdt-rhodium complex a flattened basket shaped arrangement.