Synthesis, spectroscopic and structural properties of Sn( ii ) and Pb( ii ) triflate complexes with soft phosphine and arsine coordination
Synthesis, spectroscopic and structural properties of Sn( ii ) and Pb( ii ) triflate complexes with soft phosphine and arsine coordination
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软膦、胂配位三氟甲磺酸Sn( ii )和Pb( ii )配合物的合成、光谱和结构性质
DOI：
10.1039/d2dt03687h
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发表时间：
2023
影响因子：
4
通讯作者：
Cairns K
中科院分区：
文献类型：
--
作者：
Cairns K
二价M（OTf）2的反应（M = Sn，Pb; OTf = CF 3SO 3）与软膦和胂配体L，其中L = o-C6 H4（ER 2）2（E = P，R = Me或Ph; E = As，R = Me），MeC（CH2ER2）3（E = P，R = Ph; E = As，R = Me），PhP（CH 2CH 2 PPh 2）2或P（CH 2 CH 2 PPh 2）3，得到化学计量M（L）（OTf）2的络合物，为白色粉末，其通过元素分析表征，1H，19 F {1H}，31 P {1H}和119 Sn NMR光谱，预期的31 P-119 Sn和31 P-207 Pb偶联明显。九个这些pnictine复合物的晶体结构的报告，在每种情况下揭示保留一个或两个OTf阴离子，这引起了不同范围的协调环境，包括单体，以及不同程度的低聚形成弱相关（OTf桥）二聚体，三聚体和聚合物。19 F {1H} NMR光谱表明OTf在溶液中基本上是阴离子的（解离的）。[M（OTf）2{MeC（CH 2 PPh 2）3}]与Na[BArF]（BArF = B{3，5-（CF 3）2C 6 H3}4）的阴离子复分解产生相应的[M{MeC（CH 2 PPh 2）3}][BArF]2盐，所有三种（M = Ge，Sn，Pb）的晶体结构均显示具有离散的[BArF]−阴离子的锥形配位作用，提供电荷平衡。用密度泛函理论（DFT）计算了这些[M{MeC（CH 2 PPh 2）3}]2+（M = Ge，Sn，Pb）二价阳离子的B3 LYP-D3泛函，结果表明存在定向孤对电子，它是价态s和pz特征的混合物，价态p轨道特征在第14族下降.自然键轨道（NBO）分析还表明，在金属中心的自然电荷增加，P中心的电荷减少后，向下组14。
Reaction of the divalent M(OTf)2 (M = Sn, Pb; OTf = CF3SO3) with soft phosphine and arsine ligands, L, where L = o-C6H4(ER2)2 (E = P, R = Me or Ph; E = As, R = Me), MeC(CH2ER2)3 (E = P, R = Ph; E = As, R = Me), PhP(CH2CH2PPh2)2 or P(CH2CH2PPh2)3, affords complexes of stoichiometry M(L)(OTf)2 as white powders, which have been characterised via elemental analysis, 1H, 19F{1H}, 31P{1H} and 119Sn NMR spectroscopy, with the expected 31P–119Sn and 31P–207Pb couplings clearly evident. The crystal structures of nine of these pnictine complexes are reported, in each case revealing retention of one or both OTf anions, which gives rise to a diverse range of coordination environments including monomers, as well as varying degrees of oligomerisation to form weakly associated (OTf-bridged) dimers, trimers and polymers. 19F{1H} NMR spectra indicate that the OTf is essentially anionic (dissociated) in solution. Anion metathesis of [M(OTf)2{MeC(CH2PPh2)3}] with Na[BArF] (BArF = B{3,5-(CF3)2C6H3}4) yields the corresponding [M{MeC(CH2PPh2)3}][BArF]2 salts, the crystal structures of all three (M = Ge, Sn, Pb) reveal pyramidal dications with discrete [BArF]− anions providing charge balance. Density functional theory (DFT) calculations on these [M{MeC(CH2PPh2)3}]2+ (M = Ge, Sn, Pb) dications using the B3LYP-D3 functional show the presence of a directional lone pair, which is a mixture of valence s and pz character, with the valence p-orbital character decreasing down group 14. Natural bond orbital (NBO) analysis also shows that the natural charge at the metal centre increases and the charge on the P centre decreases upon going down group 14.