Abstract
Group 9 transition metal complexes featuring a tridentate o-phenylene-bridged diphosphine N-heterocyclic carbene pincer ligand have been synthesized and investigated. [(PCNHCP)RhIII(H)(Cl)][X] [X = PF6 (1), Cl (2)] complexes have been synthesized. A RhIII complex in which a C-Cl bond in CH2Cl2 has been activated, [(PCNHCP)RhIII(CH2Cl)(Cl)2] (3), has been synthesized and isolated. Attempts to isolate the nucleophilic complexes [(PCNHCP)RhI(MeCN)][PF6] (4) and [(PCNHCP)RhI(PMe3)(Cl)] (5) were made. The resulting mixtures all undergo a thermal rearrangement decomposition process leading to mixtures containing [(PCNHCCaryl)Rh(R)(PPh2)] (R = MeCN, PMe3) (6) along with the desired product. Synthesis of NHC-Ag precursors has been investigated and discussed, and [(PCNHCP)Ag(Cl)] (7) was found to undergo a Ag-P association/dissociation process. By adding AgPF6 to the reaction mixture of NHC-Ag precursors, [(PCNHCP)2Ag2][PF6]2 (8) is also obtained by removal of a Cl- ion.