Synthesis of heptamethylindenyl rhodium(III) complexes: molecular structures of [(η5-C9Me7)RhCl(µ-Cl)]2 and [(η5-C9Me7)Rh(PMe2Ph)Cl2

Abstract

The synthesis of a series of permethylindenyl (Ind*) rhodium(III) complexes, [(η5-C9Me7)RhCl(μ-Cl)]2, [(η5-C9Me7)RhLCl2] (L = PMe3, PMe2Ph, PPh3), and [(η5-C9Me7)Rh(PMe3)2Cl]+Cl−, is reported. The structure of [(η5-C9Me7)RhCl(μ-Cl)]2, (4) was determined, confirming the dimeric nature of the compound. Ruby red crystals of 4 are monoclinic, space group C2/c, with four molecules per unit cell of dimensions a = 18.598(5), b = 10.520(3), c = 17.376(3) Å and β = 115.10(2)°. The indenyl rings exhibit minimal distortion from perfect η5 coordination to the Rh centres. A single crystal X-ray structure determination of [(η5-C9Me7)Rh(PMe2Ph)Cl2] (6) indicates a more distorted η5-coordination of the indenyl ligand, with the auxiliary ligand having the greatest trans influence, namely, the PMe2Ph group, being trans to the indenyl ring junction C—C bond. Yellow prismatic crystals of 6 are orthorhombic, space group P212121, with four molecules per unit cell of dimensions a = 8.819(1), b = 15.303(3), c = 17.296(3) Å. Keywords: rhodium, indenyl, permethylindenyl, heptamethylindenyl, phosphine complex. X-ray structure.