Synthesis and Spectroscopic and X-ray Structural Characterization of R_2Sn~(lv)-Oxydiacetate and -Iminodiacetate Complexes

摘要

Seven novel R_2Sn~(lv)-oxydiacetate (oda) and -iminodiacetate (Ida) compounds of the form [R_2Sn(oda)(H_20)]_2 (R = Me,"Bu,and Ph) (1-3),[(R_2SnCI)_2(oda)(H_20)_2]_n (R = Et,~tBu,and ~tBu) (4-6),and [Me_2Sn(ida)(MeOH)]_2 (7) have been synthesized and characterized by IR,~1H,~(13)C,and ~(119)Sn NMR (solution),solid-state ~(119)Sn CPMAS NMR,and ~(119m)Sn Mossbauer spectroscopy.The crystal structure of [Me_2Sn(oda)(H_20)]_2,1,shows it to be dinuclear (centrosymmetric),with two seven-coordinated tin atoms,bridged by one arm of the carboxylate group from each oda.By contrast,the crystal structure of [(Et_2SnCI)_2(oda)(H_20)_2]_n,4,comprises a zigzag polymeric assembly containing a pair of different alternating subunits,{Et_2SnCI(H_20)} and {Et_2SnCI(H_20)(oda)},which are connected by way of bridging oda carboxylates,thus giving seven-coordinate tin centers .in both components.Finally,the structure of [Me_2Sn(ida)(MeOH)]_2,7,also centrosymmetric dinuclear,is comprised of a pair of mononuclear units with seven-coordinate tin.The ~(119)Sn solid-state CPMAS NMR and ~(119m)Sn Mossbauer suggest the presence of seven-coordinate Sn metal atoms in some derivatives and the existence of two different tin sites in the [(R_2SnCI)_2(oda)(H_20)_2]_n compounds.