Rhodium and Iridium Aminohorane Complexes: Coordination Chemistry of BN Alkene Analogues

摘要

The chemistry of boron donor ligands, isoelectronic with classical organometallic systems, has received considerable recent attention, not only from a structure/bonding perspective, but also from a desire to develop inherently useful patterns of reactivity (e.g. boryl complexes in hydro- and diboration, and in C-H activation). Such studies have also allowed comparative assays of ligand properties and reactivity (e.g. relative trans influences, comparative reactivity towards electrophilesucleophiles) for isoelectronic carbon/boron-containing ligand families, e.g. N-heterocyclic carbene/ boryl, vinylidene/aminoborylene, CO/BF, and cyclo-pentadienyl/azaborolyl pairs. Such comparisons can also be exploited in a predictive capacity, as in the case of the ligating properties of alkanes/amineboranes, with structural data being widely available only for the latter class of donor. By contrast, while transition-metal complexes are well known for alkene ligands, the coordination chemistry of the isoelectronic aminoborane family (R2N= BX2) has yet to be elucidated, despite the potential relevance of such species to boronitrogen based hydrogen storage materials (for X = H).