Ligand design for alkali-metal-templated self-assembly of unique high-nuclearity CuII aggregates with diverse coordination cage units:: Crystal structures and properties

The construction of two unique, high-nuclearity Cu-II supramolecular aggregates with tetrahedral or octahedral cage units, {(mu(3)-Cl)[Li subset of Cu-4(mu-L-1)(3)](3)}(ClO4)(8)(H2O)(4.5) (1) and {[Na-2 subset of Cu-12 (mu-L-2)(8)(mu-Cl)(4)](ClO4)(8)(H2O)(10-)(H3O+)(2)}(infinity) (2) by alkali-metal-templated (Li+ or Na+) self-assembly, was achieved by the use of two newly designed carboxylic-functionalized diazamesocyclic ligands, N,N'-bis(3-propionyloxy)-1 4-diazacycloheptane (H2L1) or 1,5-diazacyclooctane-N,N'-diacetate acid (H2L2). Complex 1 crystallizes in the trigonal (R) over bar 3c space group (a = b = 20.866(3), c = 126.26(4) Angstrom and Z = 12), and 2 in the triclinic P (1) over bar space group (a = 13.632(4), b = 14.754(4), c = 19.517(6) Angstrom, alpha = 99.836(6), beta = 95.793(5), gamma = 116.124(5)degrees and Z = 1). By subtle variation of the ligand structures and the alkali-metal templates, different polymeric motifs were obtained: a dodecanuclear architecture I consisting of three Cu-4 tetrahedral cage units with a Li+ template, and a supramolecular chain 2 consisting of two crystallographically nonequivalent octahedral Cu-6 polyhedra with a Na+ template. The effects of ligand functionality and alkali metal template ions on the self-assembly processes of both coordination supramolecular aggregates, and their magnetic behaviors are discussed in detail.