Crystal structures and evaluated of structural transformations of three novel Lead(II) halide/pseudohalide coordination polymers: Effect of sonochemical synthesis conditions on morphology and particle size

Highlights: • Synthesis of two new nano coordination polymers (CPs) by sonochemical method. • Characterization of three CPs by single crystal X-ray diffraction. • Evaluation of solid-state transformations by mechanochemical approach. • Investigation of sonication condition effects on size and morphology of the nano-structures. A thermal gradient method (branched tube) was applied to synthesize three novel lead (II) mixed-ligand coordination polymers, [Pb(NNO) (HNNO) (I₃)]_n (1), [Pb(NNO) (SCN)]_n (2) and [Pb(PNO) (I)]_n (3), (HPNO=picolinic acid N-oxide and HNNO=nicotinic acid N-oxide) which were structurally characterized by single crystal X-ray diffraction. The thermal behavior of 1, 2 and 3 was identified by thermogravimetric analysis. Compounds 2 and 3 were also prepared by an ultrasonic process and their characterizations were carried out by IR spectroscopy, powder X-ray diffraction and scanning electron microscopy. Mechanochemical transformations of compounds 3 and [Pb(PNO) (SCN)] (4) were investigated by replacement of their anions. The particle size and morphology of compounds 2 and 3 were examined by changing the initial concentration of reagents, time and ultrasonic power.