Phosphanylphosphido and phosphanylphosphinidene complexes of zirconium(IV) supported by bidentate N,N ligands

Bonding in Phosphanylphosphinidene Complexes of Transition Metals and their Correlation with Structures, 31P NMR Spectra, and Reactivities

“…The most noticeable feature is the preference for side‐on geometry of the incoming R 2 P–P ligand and the short P–P distance within this group. Moreover, side‐on bonded phosphanylphosphinidene complexes of platinum differ substantially from the ones of earlier transition metals , . Similar properties are observed for complexes with diphosphanylphosphido ligands (R 2 P–P–PR 2 ) , .…”

“…We pay special attention to the t Bu 2 P–P moiety, because this group is a ligand in the majority of known phosphanylphosphinidene transition‐metal complexes , . Our calculations performed for this phosphinidene indicate a singlet ground state.…”

“…These compounds react with electrophilic R 2 PCl to yield neutral niobium and cationic tungsten complexes with side‐on bonded t Bu 2 P–P and Ph 2 P–P ligands (Scheme B). We have demonstrated that lithiated diphosphanes are effective precursors of phosphanylphosphinidene ligands in reactions with chlorido complexes of zirconium(IV),, , platinum(II), tungsten(VI),, molybdenum(VI), and titanium(IV) (Scheme C).…”

“…They also display η 2 ‐bonded phosphanylphosphinidene moieties with short P–P distances; however, contrary to group A, the P α (phosphinidene)–M distances are shorter than the P β (phosphanyl)–M distances. Group C is the most diversified in terms of metallic centers and includes complexes of titanium(IV) ( 5 ), zirconium(IV) ( 6 ), niobium(V) ( 7 ), and tungsten(VI) ( 8 ) , . The tungsten complex 9 is an exceptional case, because it combines the features of subclasses A and C; this will be discussed later.…”

“…Auxiliary ligands that are strong π acceptors render electrophilic properties; auxiliary σ donors enhance the nucleophilic properties , . Our research group has been mainly focused on the synthesis, and recently, on the reactivity, of complexes with phosphanylphosphinidene ligands (R 2 P–P) . These compounds can be roughly considered as a subclass of phosphinidene complexes (RP), but they often exhibit significant differences in structure and reactivity.…”