Cyclopentadiene elimination reactions for the preparation of organoindium(III) derivatives.: Crystal and molecular structures of Me2In(acac), (Me3CCH2)2In(acac), (Me)(Me3CCH2)In(acac), and [Me2InNH(t-Bu)]2

The compounds R2InO(t-Bu), R2In(acac), R2InSSiPh3, and R2InPPh2 (R = Me, CH2CMe3) and Me2InNH(t-Bu) have been prepared in nearly quantitative yields by the cyclopentadiene elimination reaction between R2In(C5H5) and the appropriate alcohol, thiol, phosphine or amine. All reactions except those of H2N(t-Bu) occur readily at room temperature. Even though solutions of R2In(C5H5) exist as equilibrium mixtures of R2In(C5H5), RIn(C5H5)(2), In(C5H5)(3), and InR3, neither methane nor neopentane was observed as a product from the above reaction mixtures. A ligand redistribution reaction between Me2In(C5H5) and (Me3CCH2)(2)In(C5H5) was used to prepare (Me)(Me)(Me3CCH2)In(C5H5) that, in turn, was reacted with H(acac) to form (Me)(Me3CCH2)In(acac), an indium compound with three different substituents. The compounds Me2In(acac), (Me3CCH2)(2)In(acac), and (Me)(Me3CCH2)In(acac) exist as centrosymmetric dimers in the solid state, but in benzene solution Me2In(acac) is a monomer-dimer equilibrium mixture, whereas (Me3CCH2)(2)In(acac) is a monomer. The thiolate Me2InSSiPh3 is an equilibrium mixture of dimers and trimers in benzene solution, but (Me3CCH2)(2)InSSiPh3 is a dimer. The phosphide Me2InPPh2 is an equilibrium mixture of monomers and dimers when dissolved in benzene. The tert-butylamide Me2InNH(t-Bu), when dissolved in benzene, is a mixture of monomers and dimers with both cis and trans configurations, but only a dimer with the trans configuration exists in the solid state.