Luminescent monomeric and polymeric cuprous halide complexes with 1,2-bis(3,5-dimethylpyrazol-1-ylmethyl)-benzene as ligand

• Two novel coordination compounds, namely [Cu2I2(dpb)]n and [CuBr(dpb)] were prepared and characterized.
• Crystal structures of the monomeric and polymeric Cu(I) halide complexes were presented.
• The Cu(I) complexes are luminescent in the solid state at ambient temperature.

Reaction of cuprous bromide with equimolar amounts of 1,2-bis(3,5-dimethylpyrazol-1-ylmethyl)-benzene (dpb) affords a mononuclear three-coordinated complex [CuBr(dpb)] (F2) with dpb acting as a chelating ligand. In contrast, using cuprous iodide instead under the same conditions gives the polymeric compound [Cu2I2(dpb)]n (F1) which contains double-bridging iodine atoms. The complexes were characterized by element analysis and 1H NMR spectroscopy, and the crystal structures were determined by single-crystal X-ray diffraction methods. The Cu(I) complexes are luminescent in the solid state at ambient temperature. Intense orange emission for complex F1 is observed, with maxima at 593 nm, probably ascribed to a combination of a halide-to-metal charge transfer and copper-centered d → s, p transitions. F2 exhibits a blue photoluminescence, with emission maximum at 515 nm, assigned to metal-to-ligand charge-transfer excited states, probably mixed with some halide-to-ligand characters.

The preparation, crystal structures, and photophysical properties of two novel coordination compounds, namely [Cu2I2(dpb)]n and [CuBr(dpb)], formed upon reacting copper(I) halides with 1,2-bis(3,5-dimethylpyrazol-1-ylmethyl)-benzene (dpb) were reported. Both of the two complexes are photoluminescent in the solid state, and their emissive properties are very dependent on their structures.Figure optionsDownload as PowerPoint slide