Investigation of crystal structure, nonlinear optical and magnetic properties of a new tetrachlorocobaltate(II) anion salt with benzyl pyridinium cation based on DFT calculation

Abstract

The crystal of a new tetrachlorocobalt(II) anion salt, [BzPy]₂[CoCl₄] (1) ([BzPy]⁺ = benzyl pyridinium), was grown by the slow evaporation solution growth method at room temperature. The salt 1 crystallizes in the monoclinic space group P2(1)/c and consists of two [BzPy]⁺ cations and one [CoCl₄]²⁻ anion in which the Co(II) ion is coordinated by four Cl atoms in a close to tetrahedral geometry. The crystal packing is stabilized by electrostatic interactions and C − H···Cl hydrogen bonds between [BzPy]⁺ cations and [CoCl₄]²⁻ anions. Powder XRD diffraction study confirms the crystalline nature and purity of the title compound. The Fourier transform infrared (FT-IR) spectrum was recorded and analyzed with the aid of DFT calculations in order to make a suitable assignment of the observed bands. The thermal stability of the hybrid crystal was analyzed by TG-DTA techniques revealing that the title crystal was stable up to 195 °C. The title salt exhibits violet and cyan fluorescence emissions upon excitation at 345 nm and weak antiferromagnetic interactions in the temperature range 2-300 K. The nonlinear optical (NLO) effect of this compound was predicted using DFT, suggesting that the title crystal is a good material for NLO applications.

Graphical Abstract

Keywords:

• Tetrachlorocobaltate(II) anion salt
• crystal structure
• NLO
• magnetic properties
• DFT

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work has been partially supported by the Science and Technology Project (2016A010103025) from Guangdong Science and Technology Department and the Undergraduates’ Innovative Experimental Program (No. 201910564138) in University from South China Agricultural University.