An X-ray absorption spectroscopic study at the mercury L-III edge on phenylmercury(II) oxygen species

The X-ray absorption spectra of the reference and model compounds HgCl2, Ph HgCl, PhHgOAc and [(PhHg)(2)OH][BF4]. H2O have been analysed in both the XA NES and EXAFS regions, and the technique was extended to determine the stru ctures of (PhHg)(2)O, PhHgOH, and the basic salts PhHgOH . PhHgNO3 and PhHg OH .(PhHg)(2)SO4, which were previously structurally uncharacterised. Resul ts indicate that (PhHg)(2)O is a molecular species with Hg-O-Hg 135 degrees , while PhHgOH contains the [(PhHg)(2)OH](+) cation and is better formulate d as [(PhHg)(2)OH]OH. The same cation is also featured in the two basic sal ts. Electrospray mass spectral studies of PhHgOH in aqueous solutions show that [PhHgOH2](+), [(PhHg)(2)OH](+) and [(PhHg)(3)O](+) co-exist in solutio n in a pH-dependent equilibrium.