Pop Alexandra, Wang Lingfang, Dorcet Vincent, Roisnel Thierry, Carpentier Jean-François, Silvestru Anca, Sarazin Yann
Departamentul de Chimie Anorganica, Facultatea de Chimie si Inginerie Chimica, Universitatea Babes-Bolyai, RO-400028 Cluj-Napoca, Romania.
Dalton Trans. 2014 Nov 21;43(43):16459-74. doi: 10.1039/c4dt02252a.
Several families of heteroleptic tetrelenes of general formulae M(E^R(NMe2))[N(SiMe3)2] and M(O^E^R(NMe2))[N(SiMe3)2] (where E = S, Se; M = Ge, Sn, Pb; R(NMe2) = 2-(Me2NCH2)C6H4] supported by organochalcogenolato ligands have been prepared and fully characterised. The coordination chemistry of these ligands containing both hard (N, O) and soft (S, Se) atoms onto metals of varying size, polarisability, electropositivity and electrostatic surface potential has been explored. In the molecular solid-state, the complexes M(E^R(NMe2))[N(SiMe3)2] are monomeric, although an occurrence of weak PbSe intermolecular interactions yielding a bimolecular species has been identified in the case of the plumbylene Pb[SeC6H4(CH2NMe2)-2][N(SiMe3)2]. On the other hand, all complexes M(O^E^R(NMe2))[N(SiMe3)2] form centro-symmetric bimetallic dimers with O-bridging atoms. Multinuclear ((29)Si, (77)Se, (119)Sn, (207)Pb) NMR spectroscopy and crystallographic studies reveal that the metal preferably remains 3-coordinated in all these heteroleptic complexes with absence of coordination of N and S/Se atoms, unless severe depletion of electronic density onto the metal is enforced. Coordination of these heteroelements can thus be achieved either through replacement of α-CH3 substituents (as in the ligand 2-(Me2NCH2)C6H4SeCH2C(Me)2O(-)) by electron-withdrawing α-CF3 moieties (as in the ligand 2-(Me2NCH2)C6H4SeCH2C(CF3)2O(-)), or else with recourse to the use of a cationizing agent leading to the formation of the ion pair {2-(Me2NCH2)C6H4SeCH2C(Me)2O}Pb·H2N{B(C6F5)3}2 where the cationic metal complex is associated to a weakly-coordinating anion. The data collated herein provide compelling evidence that the coordination chemistry of divalent tetrel elements with ligands featuring both hard and soft donors cannot be reliably anticipated by sole use of general concepts such as the HSAB theory. The related metal complexes containing the rigid 8-(NMe2)naphthalen-1-yl group are also discussed.
已经制备并完全表征了由有机硫属醇盐配体支持的通式为M(E^R(NMe2))[N(SiMe3)2]和M(O^E^R(NMe2))[N(SiMe3)2]的几类杂配四价元素化合物（其中E = S、Se；M = Ge、Sn、Pb；R(NMe2) = 2-(Me2NCH2)C6H4）。已经探索了这些同时含有硬原子（N、O）和软原子（S、Se）的配体与具有不同尺寸、极化率、电正性和静电表面势的金属之间的配位化学。在分子固态中，配合物M(E^R(NMe2))[N(SiMe3)2]是单体，不过在亚铅化合物Pb[SeC6H4(CH2NMe2)-2][N(SiMe3)2]的情况下，已确定存在产生双分子物种的弱PbSe分子间相互作用。另一方面，所有配合物M(O^E^R(NMe2))[N(SiMe3)2]都形成具有O桥连原子的中心对称双金属二聚体。多核（(29)Si、(77)Se、(119)Sn、(207)Pb）核磁共振光谱和晶体学研究表明，在所有这些杂配配合物中，金属优选保持三配位，N和S/Se原子不参与配位，除非金属上的电子密度严重耗尽。因此，这些杂元素的配位可以通过用吸电子的α-CF3基团（如在配体2-(Me2NCH2)C6H4SeCH2C(CF3)2O(-)中）取代α-CH3取代基（如在配体2-(Me2NCH2)C6H4SeCH2C(Me)2O(-)中）来实现，或者借助阳离子化剂形成离子对{2-(Me2NCH2)C6H4SeCH2C(Me)2O}Pb·H2N{B(C6F5)3}2，其中阳离子金属配合物与弱配位阴离子缔合。本文整理的数据提供了令人信服的证据，即仅使用诸如HSAB理论等一般概念无法可靠地预测二价四价元素与同时具有硬供体和软供体的配体之间的配位化学。还讨论了含有刚性8-(NMe2)萘-1-基的相关金属配合物。
