Synthesis, crystal structure, vibrational studies, optical properties and DFT calculation of a new luminescent material based Cu (II)

In this work, we report the synthesis, molecular structure, the vibrational spectral (FT-IR, FT-Raman) analysis and optical properties of the investigated novel non linear optical bis(2, 2, 6, 6– Tetramethylpiperidinium–1–yl) oxidanyl tetrachlorocuprate (II), having a general chemical formula (C9H19NO)2 [CuCl4] abbreviated as (TEMPO-H)2 [CuCl4]. The molecular structure crystallises in the orthorhombic system with the P212121 space group. The crystalline stability is installed by a zero-dimensional network using hydrogen bonds between OH⋯Cl, NH⋯Cl and CH⋯O. In addition, a 3-D Hirshfeld surface analysis was performed to study molecular interactions and connect them with 2-D fingerprint schemes to detect the relative contribution of these interactions to the crystalline structure. Molecular structure, vibrating wave number, non-linear optical characterization (NLO), and Mulliken were calculated with B3LYP/LanL2DZ (DFT the Density Functional Theory) using GAUSSIAN09. The optimized geometry and the vibrational spectra calculated results compared to experimental data, showed a good overall agreement. The UV–Visible absorption and the photoluminescence (PL) spectroscopy of (TEMPO–H)2 [CuCl4] were also presented. The unaided-eye-detectable blue luminescence emission comes from the excitonic transition in the CuCl4 anions. Finally, the electronic property was determined by time-dependent DFT (TD-DFT) approach.