Synthesis and crystal structures of Group 6 metal carbonyl complexes containing S-rich bis(pyrazol-1-yl)methane ligands
作者:Liang-Fu Tang、Wen-Li Jia、Zhi-Hong Wang、Ji-Tao Wang、Hong-Gen Wang
DOI:10.1016/s0022-328x(02)01112-9
日期:2002.4
temperature affords (NN)M(CO)4 derivatives, in which some complexes contain asymmetric substituted bis(pyrazol-1-yl)methane ligands. The X-ray crystal structure analyses indicate that the sulfur atoms in these complexes do not take part in the coordination to the metal centers, and S-rich bis(pyrazol-1-yl)methanes actually act as bidentate chelating ligands by two nitrogen atoms. It is also interesting
3(5)-甲硫基-5(3)-苯基吡唑与二溴甲烷在相转移催化条件下的反应仅产生新的配体双(3-苯基-5-甲硫基吡唑-1-基)甲烷。但是,在相同条件下3(5)-甲硫基5(3)-对甲氧基苯基吡唑或3(5)-甲硫基5(3)-叔丁基吡唑与二溴甲烷的反应分别产生三种异构体,表明取代基在配体形成过程中显着影响吡唑环的空间和电子性质。在室温下紫外线照射下,用M(CO)6(M = Cr,Mo或W)处理这些潜在的多齿配体,得到(NN)M(CO)4衍生物,其中某些配合物包含不对称取代的双(吡唑-1-基)甲烷配体。X射线晶体结构分析表明,这些络合物中的硫原子不参与与金属中心的配位,富S的双(吡唑-1-基)甲烷实际上被两个氮原子用作双齿螯合配体。同样有趣的是,为了减少甲基与羰基的排斥,这些配合物中的甲基取向远离金属中心。