Search

The simple solvothermal self-assemble of CuI, 1,4-bis(2-methyl-1H-imidazol-1-yl)butane (L1) and HI in a C2H5OH solvent at pH = 2 created a new H2(L1)2+-templated 1-D chained iodocuprate(I) [H2(L1)][Cu3I5] 1. The crystal data reveal that the Cu-I chain mode in 1 is rare. Two folded Cu2I2 cores first aggregate into a trinuclear cluster by sharing an edge. Then the extra I− ions doublely bridge these trinuclear clusters into the title 1-D chain of 1. Synchronously, a non-folded Cu2I2 cluster is formed. In 1, all of the Cu···Cu distances are smaller than 2.8 Å. The investigation on photoluminescence property indicates that with the decrease of the temperature, the photoluminescence emission for 1 exhibits a minor change from the green-yellow light (298 K) to yellow light (77 K). This means that 1 might possess the fluorescent thermochromic property. [ABSTRACT FROM AUTHOR]

Under hydro(solvo)thermal conditions, four organic bidentate bridging N,N′-donor ligands 1,3-bis(2-methylimidazol-1-yl)propane (L1), 4,4′-di(1H-imidazol-1-yl)-1,1′-biphenyl (L2), 1,2-bis(2-methyl-1H-imidazol-1-ylmethyl)benzene (L3) and 5,6,7,8-tetrahydroquinoxaline (L4) were employed to react with CuBr/CuI, generating four 2-D layered copper(i)–polymer coordination polymer materials [Cu2Br2(L1)] 1, [CuI(L2)] 2, [CuI(L3)] 3 and [CuI(L4)0.5] 4. In 1–4, different Cu–X motifs are found: a cubic Cu4Br4 core in 1; a castellated Cu–I single chain in 2; a rhombic Cu2I2 core in 3; and a staircase-like Cu–I double chain in 4. The 2-D layer networks of 1–3 can all be simplified into a simple 44 topology (planar for 1 and 3; wave-like for 2), while the 2-D layer network of 4 has a 63 topology. The photoluminescence behaviors of 1–4 under a UV lamp suggest that 1 and 2 possess fluorescence thermochromism properties. Under the UV lamp, with the decrease in temperature, (i) 1 exhibits a yellow-to-red emission; (ii) 2 exhibits a yellow-to-green emission; (iii) 3 always emits green light; and (iv) 4 never emits light. These are further confirmed by their emission spectra. From 297 K to 77 K, the emission of 1 exhibits a large red shift from 561 nm to 623 nm; the emission of 2 exhibits a large blue shift from 571 nm to 515 nm; only a minor red shift is observed for the emission of 3; and no peaks appear in the emission spectra of 4. The crystal data of 1 and 2 at different temperatures have been collected for revealing the origination of their fluorescence thermochromism properties. Based on the above investigations, the effect of the rigidity/flexibility of the organic ligand on the fluorescence thermochromism properties of copper(i)–polymer coordination polymer materials is discussed. The quantum yields at 297 K and the photoluminescence lifetimes at 297 K and 77 K for 1–3 were also measured for better understanding their photoluminescence properties. [ABSTRACT FROM AUTHOR]