title: Linear or cyclic clusters of Cu(II) with a hierarchical relationship.
abstract: The polydentate ligand 2,6-bis(5-(2-hydroxyphenyl)-pyrazol-3-yl)-pyridine, H4L, exhibits a series of coordination pockets favoring the establishment of metal sequences with predetermined motifs, together with a degree of flexibility for the formation of clusters with various overall topologies. With Cu(II) under strong basic conditions it has a marked tendency to stabilize a cyclic [Cu16L8] cluster. The sequential formation of this compound via [Cu7L8](2-) intermediates, recognized in its structure, is suggested by crystallographic evidence, which shows the persistent formation of the complex salt (NBu4)2[Cu7L8] in the presence of the organic cation. Also, the crystallographic identification of the related cluster [Cu11L5(OH)2(py)12] from similar reaction conditions underscores the rich multiplicity of species attainable from this simple reaction system.
authors.affiliation: Departament de Química Inorgànica, Universitat de Barcelona , Diagonal 645, 08028 Barcelona, Spain.
authors.forename: Gavin A
authors.initials: GA
authors.lastname: Craig
authors.forename: Mike
authors.initials: M
authors.lastname: Schütze
authors.forename: David
authors.initials: D
authors.lastname: Aguilà
authors.forename: Olivier
authors.initials: O
authors.lastname: Roubeau
authors.forename: Jordi
authors.initials: J
authors.lastname: Ribas-Ariño
authors.forename: Sergi
authors.initials: S
authors.lastname: Vela
authors.forename: Simon J
authors.initials: SJ
authors.lastname: Teat
authors.forename: Guillem
authors.initials: G
authors.lastname: Aromí