Preferences across phases: Structural preferences in Group 2 dihalide and dihydride monomers, dimers, trimers, and solids

COMP 194

Kelling J. Donald,, Department of Chemistry, University of Richmond, Gottwald Science Building, Richmond, VA 23226
Links between the bending in the group 2 dihalides and the structural preference in the dimers, trimers, and solids are examined theoretically. Structural preferences in the dihalide dimers are determined by structural preferences in the monomers: the bent monomers prefer the triply bridges C3v geometry; the linear molecules prefer the D2h doubly-bridged structure. In fact, for the most bent dihalides, like BaF2, the D2h isomer is not even a local minimum. For the solids, the bent monomers condense to form the high coordination number CaF2 and PbCl2 structure types. The rigid linear monomers prefer lower metal coordination. Connections the structural preferences in the group 2 dihalides and dihydride molecules, dimers, trimers and extended solids are assessed. Understanding connections between structural preferences in extended solids and their oligomeric building blocks may help us rationalize relative stabilities of extended solid polymorphs. Reasons for the correlations we observe in the dihaldies are discussed.

Poster Session
6:00 PM-8:00 PM, Tuesday, August 18, 2009 Walter E. Washington Convention Center -- Ballroom A, Poster

Division of Computers in Chemistry

The 238th ACS National Meeting, Washington, DC, August 16-20, 2009