杂环基丁基锡化合物的NMR研究

The NMR Studies on Some Butyl Heterocyclic Stannic Compounds

报道了通式为Ｙ＿ｎＳｎＢｕ＿（４－ｎ）的含呋喃基、噻吩基、Ｎ－甲基吡咯基、吡啶基的丁基锡（Ⅳ）的^（１３）Ｃ、^（１１９）ＳｎＮＭＲ谱。基于化学位移及偶合常数讨论了丁基及各杂环基与锡的键合性质，丁基^（１３）Ｃ谱显示，锡对丁基的影响是电正性取代诱导效应。^（１１９）Ｓｎ谱及杂环基^（１３）Ｃ谱表明，杂环与锡存在ｐπ－ｄπ相互作用。^（１３）Ｃ，^（１１９）Ｓｎ化学位移值随杂环取代数目呈线性变化，随着杂环基的增加，呋喃或噻吩的两个α－碳峰互相接近，而两个β－碳峰则逐渐分离，^（１１９）Ｓｎ峰则大幅度移向高场。

The￣(119)Sn,￣(13)C and ￣1H-NMR spectra of some butyl heterocyclic stannic compounds with a general formula of Y_n SnBu(4-n) were reported, where n=0,1,2,3,or 4 and Y may be furanyl,thiophenyl,N-methylpyrrolyl,or pyridyl group,Based on chemical shifts and coupling constants of and the bonding properties among butyl,heterocyclic group and tin and rule governing changes of NMR parameters with alternation in substituents were discussed. Butyl ￣(13)C data indicated that the influences of tin on butyl group is an electropositive inductive effect.The￣(119)Sn and heterocyclic ￣(13)C data indiated that pπ-dπ interaction is in existence between heterocyclic group and tin. The chemical Shifts of ￣(13)C and ￣(119)Sn varied linearly with the number of heterocyclic substituents(n).With increase in n,the￣(13)C resonances of two α-carbons in furan or thiophene come close to each other,while the two β-carbons peaks go apart gradually,and the￣(119)Sn resonances shift upfield markedly.