Reaction of [Et4N](2)[Te{Cr(CO)(5)}(n)] (n=2, 3) toward electrophiles: Reactivity comparison and theoretical calculations

摘要

Reactions of [Et4N](2)[Te{Cr(CO)(5)}(n)] (n = 2, 3) with a series of organic and inorganic electrophiles have been systematically studied and compared. When [Et4N](2) [Te{Cr(CO)(5)}(2)] was protonated with similar to 1.0 equiv of HBF4 in MeCN, the monohydrido Te - Cr complex [Et4N][HTe{Cr(CO)(5)}(2)] ([Et4N][1]) was obtained. However, similar protonation of [Et4N](2)[Te{Cr(CO)(5)}(3)] led to the formation of the decomposition product [Et4N](2)[Te-2{Cr(CO)(5)}(4)]. While methylation of [Et4N](2)[Te{Cr(CO)(5)}(2)] with CF3SO3Me formed mono- and dimethylated products [Et4N][MeTe{Cr(CO)(5)}(2)] and Me2Te{Cr(CO)(5)}(2) (2) stepwise, a similar reaction with [Et4N](2)[Te{Cr(CO)(5)}(3)] produced the monomethylated product [Et4N][MeTe{Cr(CO)(5)}(3)] (3). Further, when [Et4N](2)[Te{Cr(CO)(5)}(n)] (n = 2, 3) was stirred in CH2Cl2 at 0 degrees C, the Cl-functionalized products [Et4N][ClH2CTe{Cr(CO)(5)}(n)] (n = 2, [Et4N][4]; n = 3, [Et4N][5]) were produced, respectively. Similar reactions with CH2Cl2 at room temperature produced corresponding CH2-bridged dimeric products [Et4N](2)[CH2Te2{Cr(CO)(5)}(n)] (n = 4; 6, [Et4N](2)[6]). If the bisbenzyl-containing reagent ClH,C(C6H4)(2)CH2Cl reacted with [Et4N](2)[Te{Cr(CO)(5)}(n)] (n = 2, 3), the corresponding CH2(C6H4)(2)CH2-bridged dimeric complexes [Et4N](2)[H2C(C6H4)(2)CH2Te2{Cr(CO)(5)}(n)] (n = 4, [Et4N](2)[7]; n = 6, [Et4N](2)[8]) were produced. [Et4N](2)[Te{Cr(CO)(5)}(n)] (n = 2, 3) could further react with HgCl2 in THF to give corresponding Hgbridged products [Et4N](2)[HgTe2{Cr(CO)(5)}(n)] (n = 4, [Et4N](2)[9]; n = 6, [Et4N](2)[10]). Complex 9 was found to transform to complex 10 upon its reaction with HgCl2 in THE Interestingly, the novel O-2 activation product [Et4N][OTe{Cr(CO)(5)}(2)] ([Et4N][11]) was observed when [Et4N](2)[Te{Cr(CO)(5)}(2)] was bubbled with O-2 in MeCN. Complexes 1 - 11 were fully characterized by elemental analysis, spectroscopic methods, and/or single-crystal X-ray analysis. The nature of [Te{Cr(CO)(5)}(n)](2-) (n = 2, 3) and the resultant complexes were further investigated by molecular orbital calculations at the B3LYP level of the density functional theory.