Steric and electronic control of low-coordinate pnictogen bonding

This work examines the concepts of steric and electronic stabilization and provides a rationale for their application to the structure and bonding of group 15 (Pnictogen) elements.; Synthetic and ab initio studies demonstrate that electronic factors determine the bonding of pnictogenium cations (group 15 carbenoids) and suggest that the dimerization of arsenium cations is a solid-state packing phenomenon. The contrasting cycloaddition reactivity of phosphenium and arsenium cations is explained. The 2,4,6-tris(trifluoromethyl)phenyl (Fmes) substituent is not suitable for the stabilization of pnictogenium cations.; Identical reactions involving the bulky 2,4,6-tri-tbutylphenyl (Mes*) and slightly smaller 2,6-diisopropylphenyl (Dip) ligands yield either trisaminopnictines, pnictazanes or iminoaminopnictines depending on the pnictogen atom. A steric scale of relative thermodynamic stability for the structure and bonding of compounds containing the N-Pn-N (Pn = P, As, Sb, Bi) moiety is formulated.; Study of the unprecedented dimerization of Mes*N=P-OSO2CF 3 yields a qualitative assessment of kinetic and thermodynamic effects of bulky substituents. Reagents that allow for the synthesis of compounds containing the [Mes*N=As] fragment are described. These will allow for the development of a new chapter of main group inorganic chemistry.1; 1Please refer to dissertation for diagram.