No abstract

The effect of varying donor X in otherwise structurally similar O(2)S(2)X-macrocycles (L(1): X = S, L(2): X = O and L(3): X = NH) on the corresponding assembly reactions with Cu(I) halides has been demonstrated to yield three supramolecular complexes with different architectures: L(1) resulted in a discrete dimeric complex (1), while L(2) and L(3) gave respectively 1D (2) and 2D (3) coordination polymers; the solid state photoluminescence of 3 is also described.

Reaction of the O(2)S(2)X-macrocycles (L(1), X = S; L(2), X = NH; and L(3), X = O) with Cu(ClO(4))(2) x 6 H(2)O affords 1:1 (M/L) square-pyramidal Cu(II) complexes when X = S and NH but yields a rare 1:2 sandwich-type tetrahedral Cu(I) complex when X = O; the X-ray structures of all three complexes are reported. Substitution of O for S or NH in the ligand structure thus results in a donor-set-induced II/I oxidation state change of the copper, and this is accompanied by a square-pyramidal to tetrahedral topological change in the solid state. Spectrophotometric titration data (including Job plots) indicate that similar behavior occurs in acetonitrile. In further experiments aimed at investigating the generality of the above redox behavior, it was shown that the 16- and 18-membered analogs of the 17-membered L(3) also induce a similar II/I redox change in acetonitrile. It was demonstrated for L(3) that the above-induced Cu(II/I) change is also maintained when the reaction solvent is changed from acetonitrile to methanol or ethanol.

LResearch on the multi-dentate ligand system for binuclear compounds is in great demand due to the prospect that such species may serve as models of electron transfer, charge transfer and allosteric behaviors observed in biochemical system. [1][2][3] The structural topologies of the binucleating frameworks are often determined by arguments of donor system and organic linkers. Our group 4 and others 5 have reported a series of dinuclear complexes of macrocyclic ligands with discrete and continuous forms. Parallel to this, noncyclic podal ligand system often give the dinuclear complexes. A further possibility to prepare the dinuclear complexes with soft metals could be given by applying the multipodal ligands with sulfur donors in each arm. Recently, Hanton et al. 6 and our group 7 have reported a double tweezertype ligand with four thiopyridyl arms, [1,2,4,5-tetrakis(2-pyridylmethylsufanylmethyl)benzene] which forms dinuclear complexes with Cu(II) and Cd(II) instead of a polymeric array due to the three-layered π-stacking motif. In this regard, we are interested in using a ligand-directed approach to construct new discrete dinuclear complexes as well as to achieve the construction of infinite coordination polymers. Thus, the double tweezer-type ligands with non-aromatic end-groups are of particular interest. The proposed quadru-armed ligand L employs one sulfur donor as a binding site and cyclohexane end-group in each arm which, in turn, will serve to minimize the inter-and/or intramolecular interactions. In this paper, we report dimercury(II) halide complexes [Hg2(L)X4] (X = Cl: 1a, X = Br: 1b, X = I: 1c) and copper(I) iodide coordination polymer [Cu2(L)I2]n of L which were structurally characterized by single-crystal X-ray analysis. The thermal properties and comparative NMR study of the complexes were also accomplished.