Synthesis of a Series of Rhodium Complexes, TpiPrRhIL₂and TpiPrRhIII(X)(Y)(MeCN), with the Hydridotris(3,5-diisopropylpyrazolyl)borato Ligand (TpiPr) from a Versatile Precursor, (κ³-TpiPr)Rh(coe)(MeCN), and Dependence of κ²−κ³Interconversion Rate of the TpiPrLigand on the Chelate Ring Size

The labile Rh(I) species Tp iPr Rh(coe)(MeCN) ( 1 ) was prepared by the reaction of [RhCl(coe) 2 ] 2 with KTp iPr followed by crystallization from MeCN. Subsequent treatment of 1 with diphosphines and CO gave square-planar Tp iPr Rh I L 2 -type products via replacement of the coe and MeCN ligands. The Rh(III) complexes Tp iPr Rh(X)(Y)(MeCN) were obtained via oxidative addition of XY and dissociation of the coe ligand. Complex 1 serves as a versatile starting compound for a variety of Rh(I) and Rh(III) complexes containing the Tp iPr ligand. In addition, it was found that κ 2 −κ 3 interconversion of the diphosphine complexes Tp iPr Rh[Ph 2 P(CH 2 ) n PPh 2 ] becomes slower as the chelate ring size increases ( n increases).