Journal of Chemical Crystallography, Vol. 28. No. 11, 1998 Molecular structures of M(tfac) 3 (M=Al, Co) and Cu(H 2 O)(fod) 2 : Examples of unusual supramolecular architecture Cullen T. Vogelson, (1) Christopher L. Edwards, (1) Andrew N. Kobylivker, (1) Star B. Chacko, (1) Cristin E. Moran, (1) Kathryn Dalton, (1) Shawn M. Stewart, (1) Brian C. Werner, (1) Simon G. Bott, (2) * and Andrew R. Barron (1) * Received October 30, 1998 The molecular structures of Al(tfac) 3 (1), Co(tfac) 3 (2) (H-tfac = 1,1,1 -trifluoroacetylacetone) and Cu(H 2 O)(fod) 2 (3) (H-fod =1,1,1,2,2,3,3-hepta-fluoro-7,7-dimethyloctane-4,6-dione) have been determined. The metal coordination spheres in compounds 1 and 2 are essentially the same as the respective M(acac) 3 derivatives. Despite the isomorphous nature of the structures of compounds 1 and 2, the identity of the nearest intermolecular van der Waals contacts are altered by minor changes in the metal coordination sphere. The geometry about copper in compound 3 is close to that of an ideal square bipyramid with the J-diketonate ligands occupying the basal plane. The water ligand in each molecule of compound 3 is hydrogen bonded to an oxygen of a l-diketonate ligand on an adjacent molecule resulting in the formation of dimers, which form rods along the y-axis due to weak C —F---Cu interactions. Crystal data: (1) orthorhombic, Pca2 1 , a = 14.949(3), b = 19.806(4), c = 13.624(3) A, V = 4033(1) A 3 , and Z = 8, and (2) orthorhombic, Pca2 1 , a = 14.930(3), b = 19.620(4), c = 13.540(3) A, V = 3966(1) A 3 , and Z = 8,; (3) monoclinic, P2 1 /c, a = 12.447(3), b = 10.486(2) c = 21.980(4) A, p = 102.65(3)°, V = 2799(1) A 3 , and Z = 4. KEY WORDS: M(acac) 3 derivatives; isomorphous; 3-diketonate ligands; hydrogen bonding. Introduction One of the most important groups of ligands in inorganic chemistry is the B-diketonate ion (I). 1 These bidentate ligands form complexes with virtually all metal ions. The most common ligand is that of acetyla- cetonate [acac] - , in which R = R" = CH 3 and R' = H. The most prevalent p-diketonate complexes are those with the stoichiometries M(p-diketonate) 3 and M(B- diketonate) 2 . The former have D 3 symmetry and exist as enantiomers. When there are unsymmetrical B- (1) Department of Chemistry, Rice University, Houston, Texas 77005. (2) Department of Chemistry, University of Houston, Houston, Texas 77204. * Authors to whom correspondence should be addressed. diketonate ligands (i.e., those in which R ^ R"), geo- metrical isomers also exist for both the bis- and tris- complexes. 815 1074-l542/98/1100-0815$15.00/0 C 1998 Plenum Publishing Corporation