Bridged Hemilabile Allylphosphonate Ligand:  Synthesis and Crystal Structure of a New Binuclear Rhodium Complex

Abstract

The reaction of 2 equiv of the allylphosphonate CH2CHCH2P(O)(OEt)2 with [Rh(Cl)(CO)2]2 results in the formation of a new binuclear rhodium complex with two bridged bidentate allylphosphonate ligands in cis positions, reaction with carbon monoxide induces the lability of the phosphonate moiety, which is reversible.

Hemilability of Hybrid Ligands and the Coordination Chemistry of Oxazoline-Based Systems

“…It is interesting that the analogous P,S ligand did not show any hemilabile behavior but gave rise to enhanced catalysis, showing that other effects are at work 74–76. Further reactions of the kind shown in Scheme come from the dimetallic chemistry of hemilabile Si(OMe) 3 ligands77 or from dinuclear complexes with bridging allylphosphonate ligands78, 79 [Eq. (11) and (12)].…”

“…Endowed with soft and hard donor groups, phosphorus–oxygen and phosphorus–nitrogen based ligands represent the most studied class of functional phosphanes and many such examples have been presented in the previous section. The oxygen functional groups associated with the phosphorus donor come from alcohol, ether, ketone, ester, amide, and phosphane oxide or phosphonate groups 1, 2, 26, 27, 43, 78, 90–94. Although these various functions will impart significant changes in the coordination properties and hemilability of the corresponding P,O ligands, it is generally observed that phosphorus–oxygen ligands are the most weakly chelating type of ligand.…”

Fast Colorimetric Evaluation of Optimum Conditions for the Synthesis of Fluorescent Molecular Probes: Application to Neuronal TracersN,N-((Dialkylamino)styryl)-N-alkylpyridinium Salts

“…Des Abbayes and co-workers have recently described an efficient access to semi-labile phosphite/phosphonate ligands in two steps [21]. Hydroxymethyl-phosphonic acid is treated with phosphorus trichloride to obtain a dichloride intermediate.…”

Hemilabilität von Hybridliganden und die Koordinationschemie von Oxazolinliganden

“…Demzufolge müssen in diesem Fall andere Effekte die Katalyse beeinflussen 74–76. Weitere Reaktionen vom Typ der in Schema dargestellten findet man bei zweikernigen Komplexen mit hemilabilen (MeO) 3 Si‐Liganden77 oder verbrückenden Allylphosphonatliganden78, 79 [Gl. (11) bzw.…”

“…Die mit einem weichen und einem harten Donor ausgestatten P,O‐ und P,N‐Liganden, von denen einzelne in den vorausgehenden Abschnitten bereits vorgestellt wurden, gehören zu den am besten untersuchten funktionalisierten Phosphanen. In diesen Liganden können Sauerstoffatome von Alkohol‐, Ether‐, Keton‐, Ester‐, Amid‐, Phosphinoxid‐ und Phosphonatgruppen als Donoren vorkommen 1, 2, 26, 27, 43, 78, 90–94. Obwohl diese vielfältigen Funktionalitäten die Koordinationseigenschaften und das hemilabile Verhalten der jeweiligen P,O‐Liganden signifikant beeinflussen werden, wurde beobachtet, dass P,O‐Liganden äußerst schwache Chelatbildner sind.…”