The first stereochemically nonrigid monomeric two-coordinate copper(I) complexes with homoleptic and heteroleptic "N2" donor set.

A novel set of stereochemically nonrigid monomeric two-coordinate copper(I) complexes, [Cu(eta(1)-H(2)CPz''(2))(2)]ClO(4) 1, [Cu(HPz'')(2)]ClO(4) 2, and [Cu(HPz'')(eta(1)-H(2)CPz''(2))]ClO(4) 3, where Pz'' = 3,5-di-tert-butylpyrazolyl, has been synthesized and characterized by X-ray diffraction and variable-temperature (1)H NMR spectroscopy. Based on the (1)H NMR line shape analysis of complexes 1 and 2, the intramolecular fluxional process was proposed for these two-coordinate copper(I) complexes. Also, the mixed ligand complex 3 shows that these two different dynamic binding modes of the coordinated HPz'' and H(2)CPz''(2) ligands can proceed simultaneously on a single copper(I) ion.

Deliberate design of a 3D homochiral Cu(II)/l-met/Ag(I) coordination network based on the distinct soft-hard recognition principle.

A homochiral amino acid coordination network [{Ag3Cu3(l-methioninato)6(NO3)3(H2O)3}.7H2O]n, self-assembled from CuII, AgI, and l-methionine via a distinct soft-hard recognition process, shows interesting characteristics, in that it is constructed from 1D helical building blocks and contains homochiral channels in which 1D water chains are hosted. This result provides an effective and controllable strategy for the preparation of enantiopure heterometallic supramolecular structures that are relevant to biopolymers.

Proton-controllable fluorescent switch based on interconversion of polynuclear and dinuclear copper(II) complexes.

The first reversible interconversion process between a one-strand polymeric copper(II) complex {[Cu2(L1)2(ClO4)2](ClO4)2}n (1) and a dicopper(II) helicate [Cu2(L1-2H)2] (2), proceeding via a deprotonation-protonation process, can transduce fluorescence and function as a fluorescent switch simply by introducing a one fiftieth equivalent of coumarine 343 anion, a fluorophore.

Mononuclear and dinuclear copper(I) complexes of bis(3,5-dimethylpyrazol-1-yl)methane: synthesis, structure, and reactivity.

The synthesis and structures of a mononuclear copper(I) carbonyl complex [Cu(OClO3)(CO)(H2CPz2')] (3) and a dinuclear copper(I) carbonyl complex [{Cu(CO)(H2CPz2')}2(mu-pyrazine)](ClO4)2 (4), where H2CPz2' = bis(3,5-dimethylpyrazol-1-yl)methane, are described. These two compounds were generated by the carbonylation of the corresponding copper(I)-acetonitrile complexes, [Cu(H2CPz2')(MeCN)](ClO4) (1) and [{Cu(H2CPz2')(MeCN)}2(mu-pyrazine)](ClO4)2 (2). Alternatively, treatment of mononuclear 1 and 3, respectively, with pyrazine in a molar ratio of 2:1 produces the pyrazine-bridged dinuclear Cu(I) complexes 2 and 4. Each of the complexes 1-4 can react with PPh3 to generate a common three-coordinated copper(I) complex [Cu(PPh3)(H2CPz2')](ClO4) (5). The structures of complexes 1-5 were all confirmed by X-ray crystallography. Comparison of the Cu(I)-C(CO) bond distances and the CO stretching frequencies of 3 and 4 indicates the back-donating properties of d pi(Cu)-pi*(pyrazine) bonds in 4, and accordingly, stabilizes the mixed-valence species generated from 2. Complex 3, stabilized by the strong interaction between copper(I) ion and perchlorate counteranion (Cu(I)-O(ClO4) = 2.240(3) A), is a potential precursor for polynuclear copper(I) carbonyl complexes.

First example of a 2:1 cocrystal of mixed Cu(I)/Cu(II) complexes and a novel ferromagnetic bis(mu-hydroxo)dicopper(II) complex with a bis(pyrazol-1-yl)methane bidentate ligand.

A unique 2:1 cocrystal of mixed Cu(I)/Cu(II) complexes [Cu(I)(H2CPz2)(MeCN)2](ClO4) (1) and [Cu(II)(H2CPz2)2(ClO4)2] (4), a novel ferromagnetic ClO(4-)-bridged bis(mu-hydroxo)dicopper(II) complex, [Cu2(H2CPz2)2(OH)2(ClO4)](ClO4)(CH3CN)(0.5) (5), and a bischelated copper(I) complex, [Cu(H2CPz2)2](ClO4) (2), prepared from a one-pot reaction of [Cu(MeCN)4](ClO4) and H2CPz2, are described. The structures of these complexes have been determined by X-ray crystallographic methods. The Cu(I)-N(acetonitrile) bond distances in complex 1 are nonequivalent (1.907(8) and 2.034(9) A), leading to the dissociation of one MeCN to form a Y-shaped complex, [Cu(I)(H2CPz2)(MeCN)](ClO4) (3), which is oxidized readily in air to form complex 5 with a butterfly Cu2O2 core.

The effects of substitution on tetrakis(substituted imidazole)copper(II) trifluoromethanesulfonates.

The organic ligands 4-methyl-1H-imidazole and 2-ethyl-4-methyl-1H-imidazole react with Cu(CF(3)SO(3))(2).6H(2)O to give tetrakis(5-methyl-1H-imidazole-kappaN(3))copper(II) bis(trifluoromethanesulfonate), [Cu(C(4)H(6)N(2))(4)](CF(3)SO(3))(2), and aquatetrakis(2-ethyl-5-methyl-1H-imidazole-kappaN(3))copper(II) bis(tri fluoromethanesulfonate), [Cu(C(6)H(10)N(2))(4)(H(2)O)](CF(3)SO(3))(2). In the former, the Cu atom has an elongated octahedral coordination environment, with four imidazole rings in equatorial positions and two trifluoromethanesulfonate ions in axial positions. This conformation is similar to those in the analogous complexes tetrakis(imidazole)copper(II) trifluoromethanesulfonate and tetrakis(2-methyl-1H-imidazole)copper(II) trifluoromethanesulfonate. In the second of the title compounds, the ethyl groups block the central Cu atom, and a square-pyramidal coordination environment is formed around the Cu atom, with the substituted imidazole rings in the basal positions and a water molecule in the axial position.