Thermal, magnetic and spectral properties of metal quinone complexes: Part IV. Alkali metal complexes of 3-chloro-2-hydroxy-1,4-naphthoquinone Synthesis characterization and thermal studies

摘要

The reactions of 3-chloro-2-hydroxy-1,4-naphthoquinone; chlorolawsone with "Na" metal (ClLw-1), CH_3COONa (ClLw-2), NaOH (ClLw-3), KOH (ClLw-4) and K_2CO_3 (ClLw-5) have been studied. Dark brown solids obtained for ClLw-1 to ClLw-5 are characterized by elemental analysis FTIR, ~1HNMR, UV-Visible spectroscopy, thermogravimetric analysis and DSC studies. FTIR of ClLw-1 to ClLw-5 shows decrease in ~νC=O frequency after complexation of alkali metal ions and ~νOH of adsorbed as well as coordinated water molecules have been observed between 3,600 and 3,100 cm~(-1). The benzenoid protons C(5)H and C(8)H shows down field shift due to intermolecular hydrogen bonding interaction with neighboring molecules and upfield shift have been observed for C(6)H and C(7)H protons in ClLw-1 to ClLw-5 in ~1HNMR spectra. Bathochromic shift ～2 to ～5 nm have been observed for band at 287 nm. The nature of pyrolytic decomposition in chlorolawsone anion in ClLw-1 to ClLw-5 has been observed to be "gradual-1-abrupt-gradual-2". Phase transition occurred during gradual-1 pyrolytic decomposition of chlorolawsone anion in ClLw-1 to ClLw-4 has been studied by DSC.