Date of Graduation
Eberly College of Arts and Sciences
Jeffrey L Petersen
Bjorn C G Soderberg
Kung K Wang
Several six-coordinate cobaloxime compounds containing a triaryltin ligand were synthesized and characterized. These cobaloximes include (4- t-BuPy)Co(DH)2Sn(C6H4-p -tolyl)3, (4-t-BuPy)Co(DH)2Sn(C 6H4-p-t-Bu)3, (NH3)Co(DH) 2SnPh3, and (4-t-BuPy)Co(DH)2Bn. (4-t-BuPy)Co(DH)2Sn(C6H4- p-tolyl)3 crystallized in the centrosymmetric triclinic space group P-1 (Z=4) with unit cell dimensions a = 13.2949(5) A, b = 17.7508(7) A, c = 18.2240(7) A, alpha = 107.1983(13)°, beta = 91.6597(13)°, gamma = 107.6992(12)°, and Volume = 3880.5(3) A 3. The structure was isostructural with other alkyl cobaloximes. Preliminary X-ray structure analysis determined that (NH3)Co(DH)2SnPh 3 had a NH3 ligand bound to the six-coordinate octahedral cobalt center and trans to the triaryltin ligand. The para-substituted cobaloximes were synthesized through a Gringard reaction to obtain the tetraaryltin species, SnAr4, followed by an adapted Jolly redistribution procedure to obtain the triaryltin chloride species, ClSnAr3. The SnAr 4 compounds synthesized were Sn(C6H4- p-tolyl)4, Sn(C6H4-p-t-Bu) 4, and Sn(C6H4-p-OCH3) 4. The ClSnAr3 complexes synthesized successfully were ClSn(C 6H4-p-tolyl)3 and ClSn(C 6H4-p-t-Bu)3. These ClSnAr 3 complexes were used as the tin ligand to synthesize the corresponding cobaloxime compounds. Once synthesized, the cobaloximes underwent halogen cleavage titrations to investigate the effects of changes in the cobaloxime coordination environment and to compare their reactivity to that of the Co III(OEP)SnPh3. The multiple products formed through these halogen cleavage reactions indicates that the Co-Sn bond is not cleaved cleanly for these cobaloximes, unlike the porphyrins compounds. The cobaloximes react with the halogens to first cleave the Sn-C bonds through electrophilic aromatic substitution, indicating that cleavage of the Sn-C bond is more facile than cleavage of the Co-Sn bond in these compounds.
Ward, Elizabeth Marie, "Synthesis, Characterization, and Reactivity Studies of para-Substituted Triaryltin Cobaloximes" (2017). Graduate Theses, Dissertations, and Problem Reports. 6914.