Abstract
The synthesis and characterization of sodium 3,5-diacetyl-1,2,4-triazolate (4 Me ) and sodium 3,5-dibenzoyl-1,2,4-triazolate (4 Ph ), both of which can be used as head unit building blocks in Schiff-base reactions, are reported. The crystal structures of sodium 3,5-diacetyl-1,2,4-triazolate, as [4 Me (H2O)]∞, and sodium 3,5-dibenzoyl-1,2,4-triazolate, as [4 Ph (CH3OH)2]2, have been determined. The former is a helical polymer whilst the latter is a methanol-bridged dimer. The lead(II) templated cyclization reaction of sodium 3,5-dibenzoyl-1,2,4-triazolate (4 Ph ) with 1,3-diaminopropane or 1,4-diaminobutane, respectively, leads to the formation of two new [2 + 2] Schiff-base macrocycles as their lead(II) complexes, [Pb2 L 3Ph (μ-OH)]ClO4 (5) and [Pb2 L 4Ph (μ-OH)]ClO4 (6), respectively. Transmetallation of 5 with nickel(II) ions yields a novel, structurally characterized, dinickel(II) macrocyclic complex, [Ni2 L 3Ph (NCS)2] (7), which features double triazolate bridging of the two five-coordinate nickel(II) ions.
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Acknowledgements
We thank the Marsden Fund (Royal Society of New Zealand) for funding this research, including postdoctoral research fellowships to CDB and UB, and a research assistant position to Mr S. Iremonger. We thank Mr S. Iremonger and Dr M. Weitzer (supported by the Deutsche Akademie der Naturforscher Leopoldina, Germany, BMBF-LPD 9901/8-93) for their help and Dr J. Wikaira and Professor W.T. Robinson (University of Canterbury) for collecting the X-ray data for [4 Me (H2O)]∞. The University of Otago is thanked for the granting sabbatical leave to SB which facilitated the drafting of this manuscript and for the award of a summer studentship to NGW. JAK is grateful to the Tertiary Education Commission (New Zealand) for the award of a Bright Futures Top Achiever Doctoral PhD scholarship.