Synthesis, structure, and vibrational spectrum of poly-μ-pyrazine(pyrazine)(trifluoromethanesulfonato-O)copper(I)

Abstract

Orange–brown crystals of composition Cu(pyz)2(CF3SO3) (pyz = pyrazine, 1,4-diazine) were obtained from methanol solutions containing Cu(CF3SO3)2 and pyrazine in approximate 1:2 mole ratio. Single crystal X-ray diffraction and infrared and Raman spectroscopy studies are reported. Crystals of the title compound are triclinic, a = 8.312(2), b = 10.903(3), c = 8.201(2) Å, α = 92.53(2), β = 113.77(2), γ = 91.40(2)°, Z = 2, space group [Formula: see text] The structure was solved by heavy atom methods and was refined by full-matrix least-squares to R = 0.035 and Rw = 0.044 for 2458 reflections with 1 ≥ 3σ(I). The compound contains chains of copper ions linked by bidentate bridging pyrazine ligands. The coordination around each copper is completed by monodentate pyrazine and trifluoromethanesulfonato groups to produce a distorted tetrahedral CuN3O chromophore. Keywords: crystal structure, μ-pyrazine copper(I) triflate polymer, vibrational spectra.