Organotin(IV) Derivatives of Some O,C,O-Chelating Ligands

The series of organotin(IV) complexes L1-3SnPhnCl3-n, where L1-3 are O,C,O-chelating
ligands (called the pincer ligands), 2,6-bis(alkoxymethyl)phenyl-, 2,6-(ROCH2)2C6H3- (L1, R
= Me, L2, R = i-Pr, L3, R = t-Bu, n = 3−0), have been synthesized and characterized by 1H,
13C, and 119Sn NMR spectroscopy, MS-ESI spectrometry, and elemental analysis. The
structure of selected compounds L1SnPh3 (1), L1SnPh2Cl (2), L1SnPhCl2 (3), L1SnCl3 (4),
L2SnPhCl2 (7), and L3SnPhCl2 (11) was studied by X-ray crystallography and 119Sn CP/MAS NMR spectroscopy in the solid state. The determination of crystal structures reveals
the similarity of all the shapes of coordination polyhedra. The deformations of the shapes of
coordination polyhedra depend on the degree of donor−acceptor Sn−O interaction (from very
weak (interatomic distance Sn−O 2.963(1) Å) to medium-strong (2.475(1) Å)), which increases
with increasing Lewis acidity of the tin atom in the L1-3SnPhnCl3-n entities and decreases
with increasing steric demands of substituents R (from Me to t-Bu). NMR spectroscopy
indicates a similar structural arrangement of the studied compounds in solution.

本研究合成了一系列有机锡(IV)配合物L₁₋₃SnPhₙCl₃₋ₙ，其中L₁₋₃为O,C,O-螯合配体（即钳形配体(pincer ligands)），具体为2,6-双(烷氧基甲基)苯基类配体2,6-(ROCH₂)₂C₆H₃-（L₁中R为甲基，L₂中R为异丙基，L₃中R为叔丁基；n取值范围为0至3）；并通过¹H核磁共振波谱、¹³C核磁共振波谱、¹¹⁹Sn核磁共振波谱、电喷雾电离质谱(MS-ESI)以及元素分析对该系列配合物完成了表征。选取其中L₁SnPh₃（1）、L₁SnPh₂Cl（2）、L₁SnPhCl₂（3）、L₁SnCl₃（4）、L₂SnPhCl₂（7）及L₃SnPhCl₂（11）等化合物，通过X射线单晶衍射法与固态¹¹⁹Sn交叉极化魔角旋转核磁共振波谱(¹¹⁹Sn CP/MAS NMR)对其晶体结构进行了解析。晶体结构测定结果显示，所有目标配合物的配位多面体构型均具有相似性。配位多面体的构型畸变程度取决于供体-受体型Sn-O相互作用的强弱（相互作用的原子间距范围为2.963(1) Å至2.475(1) Å，从极弱到中强），该相互作用强度随L₁₋₃SnPhₙCl₃₋ₙ体系中锡原子的路易斯酸性增强而升高，随取代基R的空间位阻需求增大（从甲基到叔丁基）而降低。核磁共振波谱分析表明，所研究的配合物在溶液中具有相似的结构排布。