Spectroscopic study of intramolecular hydrogen bonding and coordination in the o-nitrophenols and o-nitrothiophenols and their organometallic derivatives

1. Study has been made of the IR and UV spectra of various substituted o-nitrophenols and o-nitrothiophenols, and their organomercury and organolead derivatives, in polar and nonpolar solvents. Constants for the complexing of these compounds with pyridine, DMSO, and hexamethylphosphorotriamide in benzene solution have been determined. 2. It is suggested that the strength of the intramolecular coordination bond could be determined through the ratio of the constants for complexing of the p- and o-substituted derivatives with coordinating reagents. 3. The coordination bonding between the PhHgO, PhHgS, and Ph3PbS groups and the o-nitro group is weak, being of the order of 1 kcal/mole or less.