Solvothermal Synthesis And Characterization Of Lower Group 14 And Transition Metal Based Extended Materials PDF Download

This dissertation describes the synthesis, characterization and reactivity of some low-coordinate, low-oxidation state heavier main group 13 and 14 element species. Chapter 2 describes the reactivity of the heavier main group 13 element digallene, (GaAr[superscript iPr4])2, (Ar[superscript iPr4] = -C6H3-2,6-(C6H3-2,6-[superscript i]Pr2)2) with group 6 transition metal hexacarbonyls under photoirradiation to form the bis(gallanediyl) complexes, trans-bis(GaAr[superscript iPr4])2M(CO)4 (M = Cr, Mo, or W). The mechanism of formation of these products was investigated both computationally and experimentally. A postulated intermediate in their formation is the monogallanediyl complex, Ga(Ar[superscript iPr4])Mo(CO)5 which was synthesized by the reaction (GaAr[superscript iPr4])2 with two equivalents Mo(CO)5NMe3. (GaAr[superscript iPr4])2 was also reacted at 25°C with Co2(CO)8 to give Ga(Ar[superscript iPr4])Co2(CO)7, in which the gallanediyl fragment is bound to each cobalt atom in a bridging fashion. Chapter 3 is an extension of the work in Chapter 2 to the reactions of the heavier main group 14 element dimetallynes, (EAr[superscript iPr4])2 (E = Ge or Sn), with group 6 transition metal hexacarbonyls under photoirradiative conditions. These reactions afforded the products {Ar[superscript iPr4]EM(CO)4}2 (E = Ge or Sn; M = Cr, Mo, or W) which featured rhomboid E2M2 cores with Ar[superscript iPr4]E units bridging transition metal tetracarbonyl fragments, M(CO)4. Chapter 4 describes the reactions of the aryl tin(II) hydrides {Ar[superscript iPr6]Sn([mu]-H)}2 (Ar[superscript iPr6] = C6H3-2,6-(C6H2-2,4,6-[superscript i]Pr6)2) and {Ar[superscript iPr4]Sn([mu]-H)}2 with phenyl acetylene and diphenyl acetylene. The reactions with diphenyl acetylene affords simple insertion of the Sn-H bond into a [pi]-bond of the alkyne to yield the products ArSnC(Ph)C(H)Ph (Ar = Ar[superscript iPr6] or Ar[superscript iPr4]). In contrast, the reaction of {ArSn([mu]-H)}2 with phenyl acetylene affords different products that are connected with the presence (Ar[superscript iPr6]) or absence (Ar[superscript iPr4]) of an isopropyl group at the remote para position of the flanking aryl rings of the terphenyl substituent. When {Ar[superscript iPr6]Sn([mu]-H)}2 is reacted with phenyl acetylene the product Ar[superscript iPr6](H)SnC(H)C(Ph)Sn(H)Ar[superscript iPr6] containing a 1,2-distannacyclobut-3-ene moiety is obtained as a colorless solid. In contrast, the reaction of {Ar[superscript iPr4]Sn([mu]-H)}2 with phenyl acetylene affords a red product of formula Ar[superscript iPr4]SnC(H)C(Ph)Sn(H)2Ar[superscript iPr4] with the tin atoms having different oxidation states of +2 and +4 as determined by solution 119Sn NMR spectroscopy. Chapter 5 describes the synthesis and characterization of the most sterically congested tetrylenes currently known: E(Ar[superscript iPr6])2 (E = Ge, Sn, or Pb). Computational studies of these tetrylenes and E(Ar[superscript Me6])2 (Ar[superscript Me6] = C6H3-2,6-(C6H2-2,4,6-Me3)2) and E(Ar[superscript iPr4])2 were also performed with and without dispersion corrections to evaluate the contribution of London dispersion force effects on the C[subscript ipso]-E-C[subscript ipso] interligand angle.