Synthesis, Electronic, Dynamic Optical and Adsorption (Monte Carlo and Molecular Dynamics) Properties of Cadmium Picolinate Coordination Polymer-2 (Cp-2)

Abstract

The cadmium picolinate coordination polymer (CP-2) was synthesized through the reaction of picolinic acid with cadmium acetate dihydrate. CP-2 was characterized using spectroscopic techniques, elemental analysis and powder X-ray diffraction. Variations in melting point, infrared and ultraviolet-visible spectra, along with the results of elemental analysis and powder X-ray diffraction, strongly support the successful formation of the cadmium-picolinic acid CP. The molecular, electronic, optical and adsorption properties of the CP-2 were studied using density functional theory (DFT), time-dependent DFT (TD-DFT), molecular dynamics (MD) and Monte Carlo (MC) simulations. The DFT calculations with B3LYP/LANL2DZ/6-311[Formula: see text]G(d,p) method provided insights into the molecular reactivity and electronic structure, revealing key reactivity parameters (such as frontier orbital energies, energy gap, electronegativity and electrophilicity) and charge distribution within the CP. Dynamic optical calculation was conducted using coupled perturbed Hartree-Fock formalism with DFT/B3LYP/LANL2DZ/6-311[Formula: see text]G(d,p) method. TD-DFT calculations elucidated the electronic absorption properties of the CP, with a low-energy transition at 341 nm. The static [[Formula: see text](0;0,0); [Formula: see text](0;0,0,0)] and dynamic [EOPE: [Formula: see text];[Formula: see text],0)]); SHG: [Formula: see text]2[Formula: see text];[Formula: see text],[Formula: see text]]; EOKE: [Formula: see text];[Formula: see text],0,0); DCSHG: [Formula: see text]2[Formula: see text];[Formula: see text],[Formula: see text],0)] nonlinear optical properties ([Formula: see text] 0.042823 au) displayed large hyperpolarizabilities, suggesting potential applications in SHG and THG. The third-order NLO properties were greater than those of the KH 2 PO 4 (standard). MC simulations explored the adsorption of selected gases (CO 2 , CH 4 , H 2 S, HCHO, NH 3 ) and 2,4-dinitrotoluene (DNT) on the CP-2, revealing strong binding interactions, particularly with H 2 S. MD simulations further confirmed the stability of the adsorbates on the CP-2 framework.