title: Dimolybdenum-containing molecular triangles and squares with diamidate linkers: structural diversity and complexity.
abstract: By employing cis-Mo2(DAniF)2(2+) (DAniF = N,N'-di(p-anisyl)formamidinate) as the vertex building block and terephthaloyldiamidate as the linker, four dimolybdenum-containing cyclic oligomers have been synthesized and structurally characterized. In these compounds, described by the general formula [cis-Mo2(DAniF)2((ArNOC)2C6H4)2]n, n = 3 and 4, the geometry and composition of the products are affected by the identity of the aromatic groups of the linker. When Ar = phenyl, n = 3 (1a and 1b); however, n = 4 for Ar = p-trifluoromethylphenyl (2) and when Ar = m-trifluoromethylphenyl (3). All these compounds have a central cavity, shaped by the diamidate linker, that is capable of serving as host to guest molecules in a selective manner. For compounds 2 and 3, self-assembly that takes place in the crystalline state entails intermolecular C-H...F-C interactions. Such interactions generate a one-dimensional network with a tunnel cross section of 10 x 10 A(2) in 2, whereas in 3, they result in a cage in which two THF molecules are encapsulated. The F...H distances vary in a broad range from 2.38 to 2.70 A.
authors.affiliation: Department of Chemistry and Laboratory of Molecular Structure and Bonding, P. O. Box 30012, Texas A & M University, College Station, Texas 77842-3012, USA.
authors.forename: F Albert
authors.initials: FA
authors.lastname: Cotton
authors.forename: Chun Y
authors.initials: CY
authors.lastname: Liu
authors.forename: Carlos A
authors.initials: CA
authors.lastname: Murillo
authors.forename: Xiaoping
authors.initials: X
authors.lastname: Wang