The heats of reaction of phosphines and phosphites with toluene-molybdenum tricarbonyl. Importance of both steric and electronic factors in determining the Mo---PR3 bond strength |
| |
Authors: | Steven P Nolan Carl D Hoff |
| |
Institution: | Department of Chemistry, University of Miami, Coral Gables, Florida 33124 U.S.A. |
| |
Abstract: | The heats of reaction of tolueneMo(CO)3 with a series of phosphines and phosphites have been measured by solution calorimetry. The order of stability toward formation of fac-(PR3)3Mo(CO)3 in THF solution is: P(OCH3)3s> PMe3 > PnBu3 > PMe2Ph> PEt3 > triphos> P(OPh)3 > PMePh2 > PPh3 > PCl3 and spans a range of 25 kcal/mol reflecting individual bond strength differences up to 8 kcal/mol. The bulky phosphines PCy3 and PtBu3 react with tolueneMo(CO)3 in THF, but 30–40 kcal/mol less heat is evolved in these reactions than with the other phosphines and phosphites. The coordinately unsaturated five-coordinate complexes (PR3)2Mo(CO)3 are proposed as the reaction products. The importance of both steric and electronic factors in the Mo---P bond is discussed. |
| |
Keywords: | |
本文献已被 ScienceDirect 等数据库收录! |