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

The synthesis of a series of permethylindenyl (Ind*) rhodium(III) complexes, [(η 5 -C 9 Me 7 )RhCl(μ-Cl)] 2 , [(η 5 -C 9 Me 7 )RhLCl 2 ] (L = PMe 3 , PMe 2 Ph, PPh 3 ), and [(η 5 -C 9 Me 7 )Rh(PMe 3 ) 2 Cl] + Cl − , is reported. The structure of [(η 5 -C 9 Me 7 )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 η 5 coordination to the Rh centres. A single crystal X-ray structure determination of [(η 5 -C 9 Me 7 )Rh(PMe 2 Ph)Cl 2 ] (6) indicates a more distorted η 5 -coordination of the indenyl ligand, with the auxiliary ligand having the greatest trans influence, namely, the PMe 2 Ph group, being trans to the indenyl ring junction C—C bond. Yellow prismatic crystals of 6 are orthorhombic, space group P2 1 2 1 2 1 , 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.