Cu(I) hybrid inorganic-organic materials with intriguing stimuli responsive and optoelectronic properties

Crystal‐to‐Crystal Transformation between Three CuI Coordination Polymers and Structural Evidence for Luminescence Thermochromism

Luminescent copper(I) complexes with halogenido-bridged dimeric core

Copper Iodide Based Hybrid Phosphors for Energy-Efficient General Lighting Technologies

Ligands L1 and L2' (L1 = N,N',N"-tris(4-pyridyl)trimesic amide, L2'=N,N',N"-tris(3-pyridinyl)-1,3,5-benzenetricarboxamide) belonging to an interesting family of tripyridyltriamides with C 3 -symmetry have been utilized to construct 3D porous or hydrogen-bonded frameworks. Through a novel single-crystal-to-single-crystal anion-exchange process, [Cd(L1) 2 -(ClO 4 ) 2 ] n (1c) can be obtained from [Cd(L1) 2 Cl 2 ] n (1b) in the presence of ClO 4 - anions. This anion-exchange process is highly selective and only the substitution of Cl - by ClO 4 - or PF 6 - could be realized; Cl - was found not to be substituted by BPh 4 - . This demonstrates that the exchange process depends on the size of the anions in relation to the size of the cavities in the host material (ca. 7.5 A). In addition, the anion-exchange properties of 1b have also been investigated by means of powder X-ray diffraction (PXRD), elemental analysis (EA), and infrared absorption spectroscopy (IR). Structurally, [Zn(L1)(NO 3 ) 2 ] n (2) consists of a 2D coordination network with five-coordinate Zn II ions. Surprisingly, different trigonal-bipyramidal Zn II ions propagate to form distinct respective sheet structures, A and B, which are packed in an A-B-A-B manner in the crystal lattice, and these are hydrogen-bonded to give a 3D extended framework. The molecular structure of [CuI-(L2')] n (3) shows that the CU 1 ion adopts a distorted tetrahedral geometry, and 3 also forms a 2D coordination network. Significantly, this 2D coordination network is further assembled into a remarkable 3D homochiral framework through triple hydrogen bonding and π···π interactions. All of these 3D coordination polymers and/or hydrogen-bonded frameworks are luminescent in the solid state, and their solid-state luminescent properties have been investigated at room temperature and/or at 77 K.

Novel Single‐Crystal‐to‐Single‐Crystal Anion Exchange and Self‐Assembly of Luminescent d10 Metal (CdII, ZnII, and CuI) Complexes Containing C3‐Symmetrical Ligands

Three new coordination polymers based on CuI and 2,3-dimethylpyrazine (2,3-dmpyz) were prepared, structurally characterized and investigated for their thermal and luminescence properties. In the ligand rich 2 : 3 compound [(CuI)2(2,3-dmpyz)3] 1 (CuI)2 dimers are found, which are connected by the N-donor ligands into chains, whereas in the structure of the 1 : 1 intermediate [(CuI)(2,3-dmpyz)] 2 (CuI)4 tetramers are found, which are also connected into chains. The crystal structure of the ligand deficient 2 : 1 compound [(CuI)2(2,3-dmpyz)] 3 is built up of CuI double chains, which are connected by the 2,3-dmpyz ligands into layers. Thermal decomposition of 1 results in its direct transformation into the ligand deficient compound 3, without the formation of the 1 : 1 compound 2 as an intermediate. A similar thermal reactivity is found for compound 2, which transforms into 3 on heating. Stirring of a crystalline suspension of pure 1 or 2 in acetonitrile, always leads to a transformation into the ligand deficient compound 3 indicating that compound 3 is the most stable of all the coordination polymers, whereas compounds 1 and 2 are metastable. The luminescence properties of the CuCl and CuI coordination polymers were investigated at 298 and 77K. It was observed that the emission maxima strongly depends on the nature of the halide atom and the composition and structure of the coordination polymers. In addition, several of these compounds show luminescence thermochromism. These results are compared with those obtained for the previously reported CuCl and CuBr(2,3-dimethylpyrazine) coordination polymers.

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Synthesis, crystal structure, thermal and luminescence properties of CuX(2,3-dimethylpyrazine) (X=Cl, Br, I) coordination polymers.

A set of CuIXL coordination polymers (X = Cl, Br, I; L = derivatives of pyrazine and bipyridine) with double-stranded staircase structures was analyzed by X-ray crystallography and luminescence spectroscopy to find a relationship between the structure and luminescence properties of the polymers. Our measurements have proved that luminescence emission wavelengths varied between 500–750 nm, after the polymers were irradiated by light with a wavelength of 370 nm. Although each coordination polymer has shown different emission maximum, we observed several interesting trends related to the structure of the compounds. There is a clear correlation between the emission maxima and the halide size and/or Cu–X distance, respectively. On the other hand, the substitution of the ligand L (pyrazine derivatives, 4,4′-bipyridine) has no significant contribution to the emission spectra. This observation supports the theory that the halide to metal charge transfer (XMCT) plays a key role in the photoluminescence of staircase polymers.

Luminescence properties of “double-stranded staircase” copper(I) halide coordination polymers with N-containing ligands

Eu(NO3)3⋅5H2O and EuCl3⋅6H2O were allowed to react with bis(diphenylphosphino)alkane dioxides Ph2P(O)(CH2)nP(O)Ph2 (n = 2, 4, 6) to obtain polymeric and binuclear complexes. The prepared compounds were structurally characterized by X-ray diffraction. Luminescence measurements (emission and excitation spectra, quantum yields, lifetimes) were compared with crystallographic data in order to find a relationship between luminescent properties of the Eu(III) complexes and their structures. The Eu(III) polymers, especially [Eu(dpphO2)2Cl2]+Cl–}n, have shown extremely long luminescence lifetimes, up to 3.73 ms, as a result of a highly protecting hydrophobic shield. Copyright © 2011 John Wiley & Sons, Ltd.

Luminescent properties of europium complexes with bis(diphenylphosphino)alkane dioxides

Eisenia lucens is an earthworm living in the organic soil layer of decomposing wood. When irritated, the worm expels coelomic fluid through pores in its body wall, exhibiting blue-green bioluminescence. The mechanism of the bioluminescence, which seems to be different from other bioluminescence systems of terrestrial animals, has been studied in this work. Many lines of evidence indicate that riboflavin stored in coelomycetes plays an important role in this glowing reaction.

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Petr Taborsky

Papers

Synthesis, crystal structure, thermal and luminescence properties of CuX(2,3-dimethylpyrazine) (X=Cl, Br, I) coordination polymers.

Luminescence properties of “double-stranded staircase” copper(I) halide coordination polymers with N-containing ligands

Luminescent properties of europium complexes with bis(diphenylphosphino)alkane dioxides

A study on bioluminescence and photoluminescence in the earthworm Eisenia lucens.

Study of alkaloid berberine and its interaction with the human telomeric i-motif DNA structure