Multinuclear NMR and crystallographic study of diorganotin valproates - Part II

详细信息    查看全文

• 作者：B.P. de Morais^a ; G.M. de Lima^a ; ^{gmlima@ufmg.br" class="auth_mail" title="E-mail the corresponding author} ; C.B. Pinheiro^b ; R.A. Burrow^c ; D.F. Back^c ; R.A.S. San Gil^d ; D.C. Menezes^e ; José ; D. Ardisson^f
• 关键词：Organotin carboxylate ; Stannoxanes ; Solid state NMR ; Structural determination ; Drum-like organotin structure
• 刊名：Polyhedron
• 出版年：2015
• 出版时间：14 December 2015
• 年：2015
• 卷：102
• 期：Complete
• 页码：344-352
• 全文大小：1409 K

文摘

The reactions of SnR₂Cl₂ {R = Me, Bu and Ph} and sodium valproate, NaO₂CCH(CH₂CH₂CH₃)₂, NaOVp yielded three diorganotin valproates [{(Me₂SnOVp)₂O}₂] (1), [{(Bu₂SnOVp)₂O}₂] (2) and [{PhSn(O)OVp}₆] (3). These stannoxanes have been authenticated in terms of infrared, ¹H and ¹³C NMR, and solution- and solid-state ¹¹⁹Sn NMR and ¹¹⁹Sn Mössbauer spectroscopy. In addition the crystallographic structures of complexes (1)–(3) have been determined by X-ray diffraction. Complexes (1) and (2) displayed two major signals in the ¹¹⁹Sn NMR spectra in solution corresponding to the exo and endocyclic SnR₂ moiety of the stannoxanes. Other minor resonances have been also observed due to dynamic processes in solution. However in the ¹¹⁹Sn MAS-NMR experiments only two down field signals were detected for complex (1), according to the presence of the exo and endocyclic organotin fragments, but with different resonance in comparison with the chemical shift obtained in solution. On the other hand little difference was observed in the ¹¹⁹Sn chemical shift of complex (3) since only one resonance was detected in solution- or in the solid-state experiments, and the signals are very close to each other.