Synthesis, characterizations and crystal structures of di-n-butyltin(IV) complexes with heteroatomic (N, O or S) acid

Two types of di-n-butyltin(IV) complexes {[nBu2Sn(O2CR)]2O}2 · L 1–4 and nBu2Sn(O2CR)2Y 5–8 (when L=H2O, R=2-pyrazine 1; L=0, R=2-pyrimidylthiomethylene 2, 1-naphthoxymethylene 3; L=C6H6, R=2-naphthoxymethylene 4; when Y=H2O, R=2-pyrazine 5; Y=0, R=2-pyrimidylthiomethylene 6, 1-naphthoxymethylene 7, 2-naphthoxymethylene 8) have been prepared in 1:1 or 1:2 molar ratios by reactions of di-n-butyltin oxide with the heteroatomic (N, O or S) carboxylic acids. The complexes 1–8 are characterized by elemental, IR, 1H and 13C NMR spectra. And except for complexes 6 and 7, the complexes 1–5 and 8 are also characterized by X-ray crystallography diffraction analyses, which reveal that the tin atom of complex 5 is seven-coordinated, while the complexes 1–4 and 8 are all hexa-coordinated. The nitrogen atom of the aromatic ring in complexes 1 and 5 participates in the interactions with the Sn atom.