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SYNTHESIS AND STRUCTURAL CHEMISTRY OF ORGANOTIN AND ORGANOSILICON COMPOUNDS
Abstract
The objective of this study is to provide information on synthesis and geometric preference for pentacoordinated and hexacoordinated tin compounds and related silicon compounds. The structural results give insight to possible transition states in reactions involving tetrahedral tin and to the similarities with reactions at tetrahedral phosphorus. Where applicable, the influence of hydrogen bonding on geometric preference is also shown. The study is divided into three parts. The first part deals with synthesis and structural characterization of anionic tin compounds and related anionic silicon compounds. The pentacoordinated anionic tin species all contain three acyclic ligands and one bidentate ring system. X-ray structures performed on three of these compounds, {C(,6)H(,4)SOSn(CH(,3))(,2)F}{Et(,4)N}, {C(,6)H(,4)CO(,2)Sn(CH(,3))(,2)Cl}{Et(,4)N}, {C(,6)H(,4)SOSn(CH(,3))(,2)I}{(C(,6)H(,5))(,4)P}, show a geometric preference for a trigonal bipryramidal arrangement about the tin atom. A related pentacoordinated silicon compound, {(C(,6)H(,4)O(,2))(,2)SnF}{Et(,4)N}, was also prepared and its X-ray structure revealed a rectangular pyramidal geometry. In general, the structures analyzed in this study follow the rules deemed important for the structural preference of pentacoordinated phosphorus compounds. The second part of this study deals with synthesis and characterization of intramolecularly coordinated triorganotin compounds. A series of triphenyltin species attached to benzoic acid derivatives were prepared. All the compounds exhibited pseudopentacoordination around the tin atom with intramolecular donation by the carboxylate oxygen. The strength of this intramolecular donation was dependent on the type of functional group attached to the benzoic acid ring and if these groups participated in intermolecular or intramolecular interactions. The functional groups on the benzoic acid were, NH(,2), OH, OCH(,3), SCH(,3), N(CH(,3))(,2) and SH. The greatest interaction between the tin and a functional group occurred when the SH ligand was present. Since triorganotin compounds are biologically active, the results of this study point to a possibility of SH interaction at the active site of an enzyme. The third part of this study deals with acid-base adduct formation between diphenyltin dichloride and sulfur and nitrogen bases. The X-ray structure of the pentamethylene sulfide acid-base adduct resulted in a trigonal bipyramid geometry with cis-chlorine ligands. This is significant because the most electronegative group Cl has been forced into an equatorial position. . . . (Author's abstract exceeds stipulated maximum length. Discontinued here with permission of author.) UMI
Subject Area
Chemistry
Recommended Citation
VOLLANO, JEAN FRANCES, "SYNTHESIS AND STRUCTURAL CHEMISTRY OF ORGANOTIN AND ORGANOSILICON COMPOUNDS" (1983). Doctoral Dissertations Available from Proquest. AAI8401112.
https://scholarworks.umass.edu/dissertations/AAI8401112