Crystal structure, DFT-study and NLO properties of the novel copper(I) nitrate π,σ-coordination compound based on 1-allyl-3-norbornan-thiourea

Abstract

This work is directed toward the synthesis, structural characterization and NLO properties investigation of the novel copper(I) nitrate π,σ-coordination compound [Cu(Anor)(CH3CN)](NO3) (1) based on 1-allyl-3-norbornan-thiourea (Anor). In the crystal structure of both Anor and 1, the organic part is disordered because of the superposition of (2S)-exo and (2R)-exo enantiomers. The Anor ligand in 1 acts as a bridging ligand, connecting Cu(I) ions into the cationic coordination polymer {[Cu(Anor)(CH3CN)]+}n through η2-allyl group and the thiourea S atom. The H atoms of the –NH– groups in the Anor structure participate in NH···S hydrogen bonding and form an infinite hydrogen-bonded layer, while the same ligand groups in the organometallic chain of 1 are linked by bifurcated NH···O bonds to the two O atoms of the same NO3– anion. The second-order nonlinear optical properties for Anor and coordination compound 1 were studied at 1064 nm generated by a nanosecond pulsed Nd:YAG laser. The corresponding values of the average first-order NLO hyperpolarizabilities calculated by the DFT method and the B3LYP functional for the Anor ligand molecule and the cation fragment confirm the experimentally determined much higher second-harmonic generation efficiency for compound 1.