Search

Several tritylium compounds [PhC][A] have been isolated by salt metathesis or halide abstraction reactions starting from PhC-X (X = halogen) and Lewis acids in good yields (A = BF, BCl, AlCl, GaCl, PF, AsF, SbF, SbCl, CHBHCl, CHBCl, CHBHBr, CFCOO, CFSO, N). The structures of 15 tritylium salts bearing different types of weakly coordinating anions (A) have been determined. The structures are discussed on the basis of ion pairing versus covalent bond formation and solid-state interactions in comparison with gas-phase data. [ABSTRACT FROM AUTHOR]

The monomer/dimer equilibrium has been studied for a series of alkyl and aryl substituted and functionalized iminochlorophosphane species of the type R-N=P-Cl. In agreement with experiment, theoretical data always favor the dimer when the group R is small, while bulky groups such as Mes* destabilize the dimer by a considerable steric repulsion. This effect is superimposed by electronic effects. Para-substitution in the aryl systems either favors the monomer (energy gain ca. 15-30 kJ/mol) when a π-electron donating group such as p-NMe is used or favors the dimer when a π-electron withdrawing group such as p-NO is used (energy gain ca. 1-13 kJ/mol). [ABSTRACT FROM AUTHOR]