Appleton Sarah E, Briand Glen G, Decken Andreas, Smith Anita S
Department of Chemistry, Mount Allison University, Sackville, New Brunswick, Canada.
Dalton Trans. 2004 Nov 7(21):3515-20. doi: 10.1039/b410320c. Epub 2004 Sep 29.
The amine coordination of lead(II) has been examined through the preparation and structural analysis of Lewis base adducts of bis(thiolato)lead(II) complexes. Reaction of Pb(OAc)(2) with 2,6-dimethylbenzenethiol affords (2,6-Me(2)C(6)H(3)S)(2)Pb (6) in high yield. The solubility of 6 in organic solvents allows for the preparation of the 1:2 Lewis acid-base adduct (2,6-Me(2)C(6)H(3)S)(2)Pb(py)(2), and 1:1 adducts (2,6-Me(2)C(6)H(3)S)(2)Pb(micro(2)-bipy) and (2,6-Me(2)C(6)H(3)S)(2)Pb(micro(2)-pyr)(9)(where py = pyridine, bipy = 4,4'-bipyridyl and pyr = pyrazine) from reaction with an excess of the appropriate amine. In contrast to 7, reaction of (C(6)H(5)S)(2)Pb (1) with pyridine afforded the 2:1 adduct (C(6)H(5)S)(4)Pb(2)(py)(10). Compounds were characterized via elemental analysis, FT-IR, solution (1)H and (13)C(1)H NMR spectroscopy, and X-ray crystallography (7-10). The structures of 7-9 show the thiolate groups occupying two equatorial positions and two amine nitrogen atoms occupying axial coordination sites, yielding distorted see-saw coordination geometries, or distorted trigonal bipyramids if an equatorial lone pair on lead is considered. The absence of intermolecular contacts in 7 and 8 result in monomeric and one-dimensional polymeric structures, respectively. Weak Pb...S intermolecular contacts in 9 result in the formation of a two-dimensional macrostructure. In contrast, the structure of , shows extensive intermolecular Pb...S interactions, resulting in five- and six-coordinate bonding environments for lead(II), and a complex polymeric structure in the solid state. This demonstrates the ability of the 2,6-dimethylphenylthiolate ligand to limit intermolecular lead-sulfur interactions, while allowing the axial coordination of amine Lewis base ligands.
通过双(硫醇根)铅(II)配合物的路易斯碱加合物的制备和结构分析,研究了铅(II)的胺配位情况。醋酸铅(II)与2,6 - 二甲基苯硫醇反应可高产率得到(2,6 - Me₂C₆H₃S)₂Pb(6)。6在有机溶剂中的溶解性使得可以制备1:2的路易斯酸碱加合物[(2,6 - Me₂C₆H₃S)₂Pb(py)₂](7),以及与过量的相应胺反应得到的1:1加合物[(2,6 - Me₂C₆H₃S)₂Pb(μ₂ - bipy)]∞(8)和[(2,6 - Me₂C₆H₃S)₂Pb(μ₂ - pyr)]∞(9)(其中py = 吡啶,bipy = 4,4'-联吡啶,pyr = 吡嗪)。与7不同,(C₆H₅S)₂Pb(1)与吡啶反应得到2:1加合物[(C₆H₅S)₄Pb₂(py)]∞(10)。通过元素分析、傅里叶变换红外光谱、溶液¹H和¹³C[¹H]₆核磁共振光谱以及X射线晶体学(7 - 10)对化合物进行了表征。7 - 9的结构表明硫醇根基团占据两个赤道位置,两个胺氮原子占据轴向配位位点,产生扭曲的跷跷板配位几何结构,如果考虑铅上的赤道孤对电子,则为扭曲的三角双锥结构。7和8中不存在分子间接触,分别导致单体和一维聚合物结构。9中弱的Pb...S分子间接触导致形成二维宏观结构。相比之下,10的结构显示出广泛的分子间Pb...S相互作用,导致铅(II)的五配位和六配位键合环境,以及固态下的复杂聚合物结构。这证明了2,6 - 二甲基苯硫醇盐配体限制分子间铅 - 硫相互作用的能力,同时允许胺路易斯碱配体的轴向配位。