Professor Brock's research interests center on the structures and properties of molecular crystals. She is particularly interested in the systematics of packing in molecular crystals, and in the design, synthesis, and characterization of solid-state molecular complexes.
Systematics of Crystal Packing
Two types of questions are being investigated. First, to what extent does molecular recognition break down during crystal growth? How often are impurities incorporated into growing crystals? How often are solid solutions formed? We are studying this question by characterizing the crystals precipitated from solutions containing two similar solutes, e.g., two different para-substituted benzoic acids or two different members of the series C6(CH3)nCl6-n. The crystals may be formed exclusively of one solute or the other, the crystals may be solid solutions, or a solid-state compound may be formed. Second, we are using the Cambridge Structural Database to answer more general questions about crystal packing; e.g., how often is the symmetry of a molecule maintained in its crystals? If a molecule has a six-fold rotation axis in solution, what is the chance that its crystals are hexagonal?
Phase Relationships: Polymorphs and Solid-State Molecular Complexes
We are combining information from single-crystal and powder diffraction studies with the results of thermal measurements to construct schematic phase diagrams for molecular crystals. While studying trans-1,2-cyclohexanediol (CHD) in this way we discovered an unusual layered compound of the diol with triphenylphosphine oxide (TPPO).