Quantum Chemical Studies on Nicotinato Lead(II) Complex [Pb(II)(C 5 H 4 NCOO) 2 ]

The title compound of nicotinato lead(II) complex [Pb$(C_5H_4NCOO)_2$] has been optimized at B3LYP/LANL2DZ and HF/LANL2DZ levels of theory. The calculated results show that the lead(II) ion adopts 2- coordinate geometry, which is the same as its crystal structure and different from the 4-coordinate geometry of isonicotinato lead(II) complex. Atomic charge distributions indicate that during forming the title compound, each nicotinic acid ion transfers their negative charges to central lead(II) ion. The electronic spectra calculated by B3LYP/LANL2DZ level show that there exist two absorption bands, which have some red shifts compared with those of isonicotinato lead(II) complex and the electronic transitions are mainly derived from intraligand $\pi$ -$\pi$ transition and ligand-to-metal charge transfer (LMCT) transition. CIS-HF method is not suitable for the system studied here. The thermodynamic properties of the title compound at different temperatures have been calculated and corresponding relations between the properties and temperature have also been obtained. The second order optical nonlinearity was calculated, and the molecular hyperpolarizability was $1.147754{\times}10^{-30}$ esu.