1083010-89-2Relevant academic research and scientific papers
Iridium derivatives of fluorinated aromatics by C-H activation: Isolation of classical and non-classical hydrides
Salomon, Marcel Ahijado,Braun, Thomas,Krossing, Ingo
, p. 5197 - 5206 (2009/02/05)
A reaction of trans-[Ir(H)5(PiPr3)2] (1) with 2,3,5,6-tetrafluoropyridine, pentafluorobenzene or 1,3-difluorobenzene in the presence of neohexene affords the square-pyramidal C-H activation products cis-trans-[Ir(4-C5NF4)(H)2(PiPr 3)2] (2), cis-trans-[Ir(C6F5)(H) 2(PiPr3)2] (4) and cis-trans-[Ir(2-C 6H3F2)(H)2(PiPr3) 2] (6). Irradiation of complex 1 with 2,3,5,6-tetrafluoropyridine or pentafluorobenzene gave the hydrides cis-trans-[Ir(4-C5NF 4)(H)2(H2)(PiPr3)2] (3) or cis-trans-[Ir(C6F5)(H)2(H 2)(PiPr3)2] (5). The presence of non-classical bound H2 moieties has been demonstrated by the measurement of T 1 times at different temperatures. For 3 the H-H distance in the H2 ligand can be estimated to be 0.82 A. The dihydride compounds 2, 4 and 6 react with CO to yield the complexes cis-trans-[Ir(Ar)(H) 2(CO)(PiPr3)2] (7: Ar = 4-C5NF 4, 8: Ar = C6F5, 9: Ar = 2-C6H 3F2). A reaction of 2 or 3 with an excess of ethylene leads to the formation of ethane and the Ir(i) ethylene complex trans-[Ir(4-C5NF4)(η2-C2H 4)(PiPr3)2] (10). Treatment of 10 with CO furnishes the Ir(i) complex trans-[Ir(4-C5NF4)(CO) (PiPr3)2] (11). The Royal Society of Chemistry 2008.
