Synthesis, structure, and properties of [Hg6P4](TiCl6)Cl: The problem of host-guest interactions

[Hg6P4](TiCl6)Cl is synthesized in an ampoule at 400 degreesC. Its crystal structure is solved on the basis of a CAD4 single-crystal experiment in a c ubic space group Pa-3 (a = 11.7675(6) Angstrom, Z = 4, R = 0.0331). The str ucture is comprised of the three-dimensional cationic framework (3)(infinit y)[Hg6P4](4+), and two different guest anions, octahedral TiCl63- and monoa tomic Cl-, trapped in the cavities of the host framework. The magnetic prop erties of the title compound reflect the presence of the Ti3+ (d(1)) center s. The host-guest interaction in [Hg6P4](TiCl6)Cl is discussed on the basis of the results of tight-binding band structure and molecular orbital calcu lations performed on the host framework and octahedral guest. (C) 2001 Acad emic Press.