847549-58-0Relevant academic research and scientific papers
Ortho phosphorylation of PPh3 to give a diphosphine and formation of a butterfly structure on a tetrairidium framework
Park, Bo Keun,Miah, Md Arzu,Kang, Hongkyu,Lee, Kwangyeol,Cho, Youn-Jaung,Churchill, David G.,Park, Sangwoo,Choi, Moon-Gun,Park, Joon T.
, p. 675 - 679 (2005)
A brief thermolysis of the bis-phosphine-substituted tetrairidium cluster Ir4(CO)10(PPh3)2 (1) in chlorobenzene (CB) converts it rapidly to the diphosphine cluster Ir 4(CO)7(μ-CO)3{κ2-Ph 2P(o-C6H4)PPh2} (2) in 53% yield, providing evidence for ortho phosphorylation at the tetrairidium cluster framework. Treatment of 2 with excess C60 affords the butterfly Ir4-C60 complex Ir 4(CO)6)(μ-CO){μ3-κ2- Ph2P(o-C6H4)P(η1-o-C 6H4)}(μ3-η2: η2η2-c60 (3) in 71% yield. Interestingly, compound 3 can be prepared directly from the thermolysis of 1 with excess C60 in moderate yield (52%). Compounds 2 and 3 have been characterized by micro-analysis, spectroscopy, and single-crystal X-ray diffraction studies. A molecular structure determination reveals that complex 2 adopts a regular tetrahedral geometry with three edge-bridging CO groups around the basal triangle and a diphosphine κ2-Ph2P(o- C6H4)PPh2 ligand chelating one of the basal iridium atoms. In contrast, complex 3 possesses a butterfly geometry in which the C60 ligand is coordinated to the lower wing of the butterfly by an arene type μ3-η2: η2:η2-C60 bonding mode. One unique feature of 3 is the presence of both ortho phosphorylated and ortho-metalated phenyl rings forming five-membered [Ir-P-C-C-P] and [Ir-Ir-P-C-C] metallocycles joined in a spiro union at the iridium-indium-bridged phosphorus atom. A crossover experiment confirms that the conversion of 1 to 2 is intramolecular. Plausible reaction pathways for the formation of 2 and 3 are proposed.
