Gómez Manuel, Hernández-Prieto Cristina, Martín Avelino, Mena Miguel, Santamaría Cristina
Departamento de Química Orgánica y Química Inorgánica, Universidad de Alcalá , Campus Universitario, E-28805 Alcalá de Henares, Madrid, Spain.
Inorg Chem. 2017 Oct 2;56(19):11681-11687. doi: 10.1021/acs.inorgchem.7b01652. Epub 2017 Sep 13.
Thermal treatment of the trichloro complexes [MCl(NR)py] (R = tBu, Xyl; M = Nb, Ta) (Xyl = 2,6-MeCH) under vacuum affords the dinuclear imido species [MCl(μ-Cl)(NR)py] (R = tBu, Xyl; M = Nb 1, 3; Ta 2, 4) with loss of pyridine. Complexes 1-4 can be easily transformed to the mononuclear starting materials [MCl(NR)py] (R = tBu, Xyl; M = Nb, Ta) upon reaction with pyridine. While reactions of compounds 1 and 2 with a series of alkylating reagents render the mononuclear peralkylated imido complexes [MR(NtBu)] (R = Me, CHPh, CHCMe, CHCMePh, CHSiMe), the analogous treatment with allylmagnesium chloride results in the formation of the dinuclear niobium(IV) derivative [(NtBu)(η-CH)M(μ-CH)(μ-Cl)M(NtBu)py] (5). Additionally, the treatment of the starting materials 1 and 2 with the organosilicon reductant 1,4-bis(trimethylsilyl)-1,4-diaza-2,5-cyclohexadiene yields the pyridyl-bridged dinuclear derivatives MCl(μ-Cl)(NtBu)py (M = Nb 6, Ta 7). Controlled hydrolysis reaction of 1 and 2 affords the oxo chlorido-bridged products MCl(μ-Cl)(NtBu)py (M = Nb 8, Ta 9) in a quantitative way, while the treatment of these latter with one more equivalent of pyridine led to complexes MCl(NtBu)py (M = Nb 10, Ta 11). Structural study of these dinuclear imido derivatives has been also performed by X-ray crystallography.
在真空条件下对三氯配合物[MCl(NR)py]（R = tBu，Xyl；M = Nb，Ta）（Xyl = 2,6-Me₂C₆H₃）进行热处理，会失去吡啶，生成双核亚氨基物种[MCl(μ-Cl)(NR)py]（R = tBu，Xyl；M = Nb 1，3；Ta 2，4）。配合物1 - 4与吡啶反应时，可轻松转化为单核起始原料[MCl(NR)py]（R = tBu，Xyl；M = Nb，Ta）。虽然化合物1和2与一系列烷基化试剂反应会生成单核全烷基化亚氨基配合物[MR(NtBu)]（R = Me，CH₂Ph，CH₂CMe₂，CH₂CMePh，CH₂SiMe₃），但用烯丙基氯化镁进行类似处理会生成双核铌(IV)衍生物[(NtBu)(η³-CH₂CHCH₂)M(μ-CH₂)(μ-Cl)M(NtBu)py]（5）。此外，用有机硅还原剂1,4 - 双(三甲基硅基)-1,4 - 二氮杂 - 2,5 - 环己二烯处理起始原料1和2，会生成吡啶基桥联的双核衍生物MCl(μ-Cl)(NtBu)py（M = Nb 6，Ta 7）。对1和2进行可控水解反应，可定量得到氧氯桥联产物MCl(μ-Cl)(NtBu)py（M = Nb 8，Ta 9），而用再多一当量的吡啶处理这些产物会得到配合物MCl(NtBu)py（M = Nb 10，Ta 11）。还通过X射线晶体学对这些双核亚氨基衍生物进行了结构研究。
