Polyhedral Rearrangements in the Complexes of Rhodium and Iridium with Isomeric Carborane Anions [7,8-Me<sub>2</sub>-X-SMe<sub>2</sub>-7,8-<i>nido</i>-C<sub>2</sub>B<sub>9</sub>H<sub>8</sub>]<sup>−</sup> (X = 9 and 10)
作者:Mikhail M. Vinogradov、Yulia V. Nelyubina、Alexander A. Pavlov、Valentin V. Novikov、Nikita V. Shvydkiy、Alexander R. Kudinov
DOI:10.1021/acs.organomet.6b00858
日期:2017.2.27
Polyhedral rearrangement of iridacarborane 1,2-Me-2-3,3-(cod)-4-SMe2-3,1,2-closo-IrC2B9H8 (1) proceeds in a solution at RT and affords a product of 1,2 -> 1,7 isomerization 1,8-Me-2-2,2-(cod)-7-SMe2-2,1,8-closo-IrC2B9H8 (2). Rhodium derivative 1,2-Me-2-3,3-(cod)-4-SMe2-3,1,2-closo-RhC2B9H8 (3) is significantly more stable toward heating than iridium complex 1 and isomerizes at 110 degrees C by 1,2 -> 1,2 and 1,2 -> 1,7 reaction schemes with 1,2 -> 1,2 being the predominant route forming 1,2-Me-2-4,4-(cod)-8-SMe2-4,1,2-closo-RhC2B9H8 (4) and 1,8-Me-2-2,2-(cod)-7-SMe2-2,1,8-closo-RhC2B9H8 (5). Complexes 4 and 5 were characterized by B-11H-1}-B-11H-1} COSY NMR spectrometry. A mechanism of 1,2 -> 1,2 isomerization of 3 to 4 was proposed on the basis of DFT calculations. Reaction of the thallium salt Tl[7,8-Me-2-9-SMe2-7,8-nido-C2B9H8] (CarbTl) with [Cp*RuCl](4) in THE furnishes new ruthenacarborane 1,2-Me-2-3-(Cp*)-4-SMe2-3,1,2-closo-RuC2B9H8 (6). Heating of 6 at 80 and 144 degrees C leads to the partial and complete decomposition, respectively. Interaction of CarbTl with [Cp*IrCl2](2) in the presence of TlPF6 provides two new Ir(III) complexes [1,2-Me-2-3-(Cp*)-4-SMe2-3,1,2-closo-IrC2B9H8]PF6 (7PF(6)) and 1,2-Me-2-3-(Cp*)-4-SMe-3,1,2-closo-IrC2B9H8 (8) both stable upon heating in boiling tetrachloroethane.(146 degrees C). A new 10-substituted charge-compensated carborane [7,8-Me-2-10-SMe2-7,8-nido-C2B9H9] (9) was synthesized via an interaction of dicarbollide dianion [7,8-Me-2-7,8-nido-C2B9H9](2-) with dimethyl sulfide and acetaldehyde in acidic media. Thallium salt of 9 Tl[7,8-Me-2-10-SMe2-7,8-nido-C2B9H8] (10) reacts with [(cod)IrCl](2) furnishing positional isomer of 1 with a symmetrical emplacement of SMe2 substituent complex 1,2-Me-2-3,3-(cod)-8-SMe2-3,1,2-closo-IrC2B9H8 (11). Iridacarborane 11 requires elevated temperatures to undergo cage isomerization and converts upon heating at 110 degrees C to two new compounds 1,8-Me-2-2,2-(cod)-11-SMe2-2,1,8-closo-IrC2B9H8 (12) and 1,2-Me-2-4,4-(cod)-9-SMe2-4,1,2-closo-IrC2B9H8 (13) as a result of 1,2 -> 1,7 and 1,2 -> 1,2 rearrangements respectively with 13 being the minor product. The structures of 2, 6, 7PF(6), 8, 10, 12, and 13 were determined by single-crystal X-ray diffraction.