The quest for ring opening of oxaphosphirane complexes: a coupled-cluster and density functional study of CH(3)PO isomers and their Cr(CO)(5) complexes.

Opening gambit: A high-level theoretical study on the relative stabilities of oxaphosphirane isomers and their Cr(CO)(5) complexes is reported (see picture). Furthermore, thermodynamics and kinetics of possible ring-opening reactions of these complexes in the presence of a {Cp(2)Ti(III)Cl} fragment are theoretically investigated. The C--O bond cleavage is predicted to be the most efficient pathway, thus leading to reactive intermediates that are attractive for synthetic applications.A high-level theoretical study on the relative stabilities of oxaphosphirane isomers and their Cr(CO)(5) complexes is reported. Furthermore, thermodynamics and kinetics of possible ring-opening reactions of these complexes in the presence of a {Cp(2)Ti(III)Cl} fragment are theoretically investigated. The C--O bond cleavage is predicted to be the most efficient pathway thus leading to reactive intermediates that are attractive for synthetic applications. The ring-opening reaction is predicted to not lead to the most favorable product (a coordinated phosphinidene oxide species). Rather, the ring-opening product is separated by a substantial barrier of about 24 kcal mol(-1) from the thermodynamically most favorable species.