Crystal Structure of 1,2,3,4-Tetrahaptohexakiscarbomethoxybenzene (η5-Pentamethylcyclopentadienyl) Rhodium Complex.

The title complex (1), C28H33O12Rh, has been isolated as a major product during the reaction of strained azido thiourea rhodium complex with dimethyl acetylene dicarboxylate. This compound is isolated as air-stable bright red crystals and crystallizes in the triclinic space group P 1 ¯ with Z = 2. The Rh(I) atoms, lying on center, are coordinated by the four carbon atoms of the benzene ring. The Rh atom revealed an unusual heptahedral coordination sphere. It is one of the rare examples of compounds formed by cyclotrimerization of alkynes. The Cp* moiety is disordered over two sets of sites with occupancies of 50%. Ball and stick depiction of compound 1. Hydrogen atoms were omitted for clarity [ABSTRACT FROM AUTHOR]