Aggregate, Polymer and Cluster Formation from Metal-Imino Carboxylate Complexes

• Published in: Journal of inclusion phenomena and molecular recognition in chemistry 2001-12, Vol.41 (1-4), p.23-30
• Main Authors: Doble, Dan M J, Kay, Richard D, Benison, Colin H, Blake, Alexander J, Lin, Xiang, Wilson, Claire, Schroder, Martin
• Format: Article
• Language: English
• ISSN: 0923-0750
• DOI: 10.1023/A:1014472019855

Reaction of tris-(2-aminoethyl)amine (tren) andthe sodium salt of an {/content/kv0b1q8nf9hwb4yb/xxlarge945.gif}-ketocarboxylic acid, typically sodium pyruvate, affordsin the presence of a lanthanide ion aseries of complexes and aggregates includingmononuclear, cyclic tetranuclear and polymerspecies of [L] ([L]=N[CH2CH2N=C(CH3)COO]).The aggregation of these and related d-block elementcomplexes with Na ions leadsto the formation of polymeric materials, and thefactors influencing the formation and controlof these various aggregation states are discussed.Metal cations also template the aggregationof the fragment [Ni(L)] ([L] =CH2[CH2N = C(CH3)COO]2)to give, in high yield, the polynuclearaggregates {[Ni(L)]6M}(M = Nd, Pr, Ce, La, x = 3; M = Sr, Ba, x = 2). The structures of{[Ni(L)]6M} show aninterstitial twelve co-ordinate, icosahedralcation M encapsulated by six [Ni(L)]fragments. In the presence ofNa, aggregation of [Ni(L)] fragments affords {[Ni(L)]9Na4(H2O)(MeOH)(ClO4)} thestructure of whichshows four Na ions templating the formation ofa distorted tricapped trigonal prismatic[Ni(L)]9 cage. Thus, control overconstruction of various polynuclear cages viaself-assembly at octahedral junctions can beachieved using main group, transition metaland lanthanide ion templates.