Synthesis and Crystal Structure of Novel Sn-O Clusters Generated from nBu2SnO and Esters

T A facile and credible strategy was demonstrated to synthesize two new Sn-O clusters 1 and 2 by the reactions of nBu2SnO with esters directly under mild conditions.Cluster 1 crystallizes in the triclinic system,space group P1 with α=13.054(3),b=13.137(3),c=15.077(3)(A),α=80.009(9),β=77.187(10),γ,=76.075(11)°,Z=2,V=2427.3(9)(A)3,Dc=1.565g/cm3,μ(MoKa)=2.076 mm-1,F(000)=1152,the final R=0.0335 and wR=0.0664 for 9416observed reflections(Ⅰ＞2σ(Ⅰ)).Cluster 2 belongs to the monoclinic system,space group P21/cwith α=13.673(3),b=13.342(3),c=16.296(4)(A),β=104.385(5)°,Z=4,V=2879.7(10)(A)3,Dc=1.347 g/cm3,μ(MoKa)=1.751 mm-1,F(000)=1176,the final R=0.0306 and wR=0.0706 for 6390 observed reflections(Ⅰ＞2σ(Ⅰ)).The crystal structures of the clusters consist of centrosymmetric[RCOOSnnBu2OSnnBu2OH)]2 molecules with an almost planar Sn4O4 framework.Each pair of exo-and endo-cyclie tin atoms was linked by one bridge-OH only.In addition,a novel structure of nBu2SnO different from the previous reports was proposed on the basis of 1HNMR,TG analysis and X-ray diffraction.