1314905-86-6Relevant articles and documents
Carborane complexes of ruthenium(III): Studies on thermal reaction chemistry and the catalyst design for atom transfer radical polymerization of methyl methacrylate
Grishin, Ivan D.,D'Yachihin, Dmitrii I.,Piskunov, Alexander V.,Dolgushin, Fedor M.,Smol'Yakov, Alexander F.,Il'In, Mikhail M.,Davankov, Vadim A.,Chizhevsky, Igor T.,Grishin, Dmitry F.
, p. 7574 - 7585 (2011)
The heating of the 18-electron complex [3,3-(dppb)-3-H-3-Cl-closo-3,1,2- RuC2B9H11] (3) in benzene at 80 °C in the presence of a small amount of CCl4 as initiator afforded paramagnetic 17-electron species [3,3-(dppb)-3-Cl-closo-3,1,2-RuC2B 9H11] (4) along with minor amounts of two P-phenylene ortho-cycloboronated derivatives [3-Cl-3,3,8-{Ph2P(CH 2)4PPh-μ-(C6H4-ortho)}-closo-3,1, 2-RuC2B9H10] (5) and [3,7-Cl 2-3,3,8-{Ph2P(CH2)4PPh-μ-(C 6H4-ortho)}-closo-3,1,2-RuC2B9H 10] (6) in total yield of ca. 80%. The heating of either 3 or 4 in toluene at 95 °C in the absence of CCl4 led to the selective formation of 5, which was isolated in 64% and 46% yield, respectively. Thermolysis of 3 at higher temperatures (boiling toluene, 110 °C) gives novel paramagnetic species [3-Cl-3,3,7,8-{Ph2P(CH2) 4P-μ-(C6H4-ortho)2}-closo-3,1,2- RuC2B9H9] (7) featuring bis(ortho- cycloboronation) of both P-phenyl groups at the same phosphorus atom of the ruthenium-bound dppb ligand. All new paramagnetic complexes 4-7, as well as starting diamagnetic species 3, were characterized by single-crystal X-ray diffraction and, in addition, by EPR spectroscopic studies of odd-electron complexes. Ruthenacarboranes 3-5 and 7 all display high efficiency as catalysts for the atom transfer radical polymerization (ATRP) of methyl methacrylate (MMA). Complex 5 gave the best catalyst performance in terms of polydispersity; the PDI (Mw/Mn) of the polymer samples is as low as 1.15.
