Shankar Ravi, Kumar Mukesh, Chadha Raj K, Hundal Geeta
Department of Chemistry, Indian Institute of Technology, Hauz Khas, New Delhi 110016, India.
Inorg Chem. 2003 Dec 15;42(25):8585-91. doi: 10.1021/ic035008z.
Reactions of the tin precursors, R2Sn(OMe)OSO2Me (R=n-Pr, n-Bu), with an equimolar quantity of 2-quinoline/4-methoxy-2-quinoline/1-isoquinoline carboxylic acid in acetonitrile proceed under mild conditions (rt,12-15 h) via selective Sn-OMe bond cleavage to afford the corresponding mixed-ligand diorganotin derivatives [R2Sn(O2CR')OSO2Me]2 [R'=C9H6N-2, R=n-Pr (1), n-Bu (2); R'=4-OMe-C9H5N-2, R=n-Pr (3), n-Bu (4); R'=C9H6N-1, R=n-Pr (5), n-Bu (6)]. These have been characterized by FAB mass, IR, and multinuclear (1H, 13C, 119Sn) NMR spectral data and X-ray crystallography (for 4 and 6). The molecular structure of 4 (C20H29NO6SSn, monoclinic, P2(1)/n, a=14.1(13) A, b=16.7(18) A, c=20.3(19) A, beta=107(4) degrees, Z=8) comprises distorted octahedral geometry around each tin atom by virtue of weakly bridging methanesulfonate [Sn(1A)-O(3B)=3.010, Sn(1B)-O(3A)=2.984 A] and (N,O) chelation of the carboxylate ligands. The spectral data of 1-4 suggest a similar structural motif in solution. The molecular structure of 6 (C38H53N2O10S2Sn2, monoclinic, P2(1)/c, a=11.339(2) A, b=14.806(3) A, c=24.929(5) A, beta=100.537(3) degrees, Z=4) reveals varying bonding preferences with monomeric units being held together by a bridging methanesulfonate [Sn(2)-O(5)=2.312(2) A] and a carboxylate group bonded to Sn(1) and Sn(2) atoms, respectively. Slow hydrolysis of compound 2 derived from 2-quinoline carboxylic acid in moist CH3CN affords the asymmetric distannoxane, [Bu2Sn(O2CC9H6N-2)-O-Sn(OSO2Me)Bu2]2 (7) (C27H45NO6SSn2, monoclinic, C2/c, a=21.152(3) A, b=13.307(2) A, c=26.060(4) A, beta=110.02(10) degrees, Z=8) featuring ladder type structural motif by virtue of unique mu2-coordination of covalently bonded oxygen atoms [O(6), O(6)#1] of the methanesulfonate groups.
二烷基锡前体R2Sn(OMe)OSO2Me（R = 正丙基，正丁基）与等摩尔量的2-喹啉/4-甲氧基-2-喹啉/1-异喹啉羧酸在乙腈中，于温和条件下（室温，12 - 15小时）通过选择性的Sn - OMe键断裂反应，得到相应的混合配体二有机锡衍生物[R2Sn(O2CR')OSO2Me]2 [R' = C9H6N - 2，R = 正丙基(1)，正丁基(2)；R' = 4 - OMe - C9H5N - 2，R = 正丙基(3)，正丁基(4)；R' = C9H6N - 1，R = 正丙基(5)，正丁基(6)]。这些产物已通过快原子轰击质谱、红外光谱以及多核（1H、13C、119Sn）核磁共振光谱数据和X射线晶体学（针对4和6）进行了表征。4（C20H29NO6SSn，单斜晶系，P2(1)/n，a = 14.1(13) Å，b = 16.7(18) Å，c = 20.3(19) Å，β = 107(4)°，Z = 8）的分子结构中，每个锡原子周围呈现扭曲的八面体几何构型，这是由于甲磺酸根的弱桥连作用[Sn(1A) - O(3B) = 3.010，Sn(1B) - O(3A) = 2.984 Å]以及羧酸根配体的（N，O）螯合作用。1 - 4的光谱数据表明在溶液中存在类似的结构基序。6（C38H53N2O10S2Sn2，单斜晶系，P2(1)/c，a = 11.339(2) Å，b = 14.806(3) Å，c = 24.929(5) Å，β = 100.537(3)°，Z = 4）的分子结构显示出不同的键合偏好，单体单元通过桥连的甲磺酸根[Sn(2) - O(5) = 2.312(2) Å]以及分别与Sn(1)和Sn(2)原子相连的羧酸根基团结合在一起。由2 - 喹啉羧酸衍生的化合物2在潮湿的CH3CN中缓慢水解，得到不对称二锡氧烷[Bu2Sn(O2CC9H6N - 2) - O - Sn(OSO2Me)Bu2]2 (7)（C27H45NO6SSn2，单斜晶系，C2/c，a = 21.152(3) Å，b = 13.307(2) Å，c = 26.060(4) Å，β = 110.02(10)°，Z = 8），该化合物具有阶梯型结构基序，这是由于甲磺酸根基团中共价键合的氧原子[O(6)，O(6)#1]的独特μ2配位作用。
