Reactivity of 16-electron half-sandwich cobalt compounds containing a chelating 1,2-dicarba-closo-dodecaborane-1,2-dithiolate ligand towards methyl propiolate and dithio ligands
作者:Rui Zhang、Lin Zhu、Zhenzhong Lu、Hong Yan、Vladimir I. Bregadze
DOI:10.1039/c2dt31425h
日期:——
The reaction of the 16-electron half-sandwich complex MeCpCo(S2C2B10H10) (1b; MeCp = methylcyclopentadienyl) and methyl propiolate (HCCCO2Me) at ambient temperature leads to MeCpCo(S2C2B10H9)(CHCHCO2Me) (2), MeCpCo(S2C2B10H8)(CHCHCO2Me)2 (3), MeCpCo(S2C2B10H9)[MeO2CCCH(MeO2C)CCH)](CHCHCO2Me) (4) and MeCpCo(S2C2B10H9)(CH2CCO2Me) (5). The reaction of Me4CpCo(S2C2B10H10) (1c; Me4Cp = tetramethylcyclopentadienyl) and the alkyne gives rise to Me4CpCo(S2C2B10H10)[MeO2CCCH(MeO2C)CCH] (6) and Me4CpCo (S2C2B10H9)(CH2CCO2Me) (7). Both 2 and 3 are 16-electron complexes but containing a B(3)-substituted o-carborane-1,2-dithiolate ligand in 2 and a B(3,6)-disubstituted o-carborane-1,2-dithiolate ligand in 3, respectively. In 4 and 6, two alkynes are inserted into one Co–S bond to meet an 18 electron configuration at metal, however, 4 has one B-substitution at carborane. Both 5 and 7 have the same structural type bearing a B–CH2 unit. The reactions of Cp#Co(E2C2B10H10) [Cp# = Cp (1a), MeCp (1b), Me4Cp (1c) and Me5Cp (1d); E = S, Se] with 2-methylpropanedithioic acid (L1) or pyrrolidine-1-carbodithioic acid (L2) lead to Co[S2CCH(CH3)2]3 (8) or Co[S2CN(CH2)4]3 (9), respectively, in an octahedral geometry. The three-component reactions of 1a–1d, methyl propiolate and L1 or L2 afford seven new compounds Cp#Co[S2C2B10H10(CHCHCO2Me)][S2CCH(CH3)2] [Cp# = Cp (10a), MeCp (10b) and Me4Cp (10c)], [S2CCH(CH3)2]2Co(S2C2B10H10)(CHCCO2Me)CpCo[S2CCH(CH3)2]} (11a), Cp#Co[S2C2B10H10(CHCHCO2Me)][S2CN(CH2)4] [Cp# = Cp (12a), MeCp (12b) and Me4Cp (12c)]. All 10a–10c and 12a–12c contain one deprotonated L1 or L2 ligand and one reduced alkyne. 11a has two 18-electron Co centers linked by one reduced alkyne. One metal is coordinated by an o-carborane-1,2-dithiolate and two L1 ligands, and the other is coordinated by one L1 ligand and one η5-Cp unit. In both two- and three-component reactions the reactivity of the 16-electron half-sandwich complexes Cp#Co(S2C2B10H10) is dependent on the size of the Cp# unit. All compounds were fully characterized by spectroscopic techniques and elemental analysis. The solid-state structures of 4, 5, 7, 10a and 11a were further determined by X-ray crystallographic analysis.
16电子半三明治配合物MeCpCo(S2C2B10H10) (1b; MeCp = 甲基环戊二烯基)与甲基丙炔酸酯(HCCCO2Me)在室温下反应,生成MeCpCo(S2C2B10H9)(CHCHCO2Me) (2)、MeCpCo(S2C2B10H8)(CHCHCO2Me)2 (3)、MeCpCo(S2C2B10H9)[MeO2CCCH(MeO2C)CCH](CHCHCO2Me) (4)和MeCpCo(S2C2B10H9)(CH2CCO2Me) (5)。Me4CpCo(S2C2B10H10) (1c; Me4Cp = 四甲基环戊二烯基)与炔烃的反应生成Me4CpCo(S2C2B10H10)[MeO2CCCH(MeO2C)CCH] (6)和Me4CpCo(S2C2B10H9)(CH2CCO2Me) (7)。2和3均为16电子配合物,但2中含有B(3)-取代的o-硼烷-1,2-二硫配体,而3中含有B(3,6)-二取代的o-硼烷-1,2-二硫配体。在4和6中,两种炔烃插入一个Co–S键,以达到金属的18电子构型,但4在车伯烷上有一个B取代。5和7具有相同的结构类型,含有B–CH2单元。Cp#Co(E2C2B10H10) [Cp# = Cp (1a)、MeCp (1b)、Me4Cp (1c)和Me5Cp (1d); E = S, Se]与2-甲基丙烯二硫酸(L1)或呋喃-1-羧基二硫酸(L2)的反应分别生成Co[S2CCH(CH3)2]3 (8)或Co[S2CN(CH2)4]3 (9),呈八面体几何结构。1a–1d、甲基丙炔酸酯及L1或L2的三组分反应生成七个新化合物Cp#Co[S2C2B10H10(CHCHCO2Me)][S2CCH(CH3)2] [Cp# = Cp (10a)、MeCp (10b)和Me4Cp (10c)]、[S2CCH(CH3)2]2Co(S2C2B10H10)(CHCCO2Me)CpCo[S2CCH(CH3)2]} (11a)以及Cp#Co[S2C2B10H10(CHCHCO2Me)][S2CN(CH2)4] [Cp# = Cp (12a)、MeCp (12b)和Me4Cp (12c)]。所有10a–10c和12a–12c均包含一个去质子化的L1或L2配体和一个还原的炔烃。11a具有两个18电子的Co中心,通过一个还原的炔烃连接。一个金属由一个o-硼烷-1,2-二硫配体和两个L1配体配位,另一个由一个L1配体和一个η5-Cp单元配位。在两组分和三组分反应中,16电子半三明治配合物Cp#Co(S2C2B10H10)的反应性取决于Cp#单元的大小。所有化合物均通过光谱技术和元素分析进行了充分表征。4、5、7、10a和11a的固态结构进一步通过X射线晶体学分析确定。