Trimercurated acetic acid. The crystal structures of [Hg(H 2OHg)(NO 3Hg)CCOO]NO 3 and 2(NO 3Hg) 3CCOOH·HNO 3

Abstract

Two nitrates of trimercurated acetic acid, obtained from the solution of mercuretin in nitric acid, were identified as [Hg(H 2OHg)(NO 3Hg)CCOO]NO 3 ( A) and 2(NO 3Hg) 3CCOOH·HNO 3 ( B) by X-ray diffraction. The cation of A is an infinite chain composed of the -Hg(H 2OHg)(NO 3Hg)CCOO- units joined through the CHgO linkages with mean bond lengths of 2.08(3) (CHg) and 2.11(3) Å (HgO). The chains are connected by hydrogen bonding between the water molecule and the carboxyl oxygen with OH⋯O distances of 2.61(4) Å. The structure of B consists of discrete molecules of (NO 3Hg) 3CCOOH. One half of the molecules in the unit cell join up to give centrosymmetrical pairs through the carboxyl groups, with OH⋯O bonds of 2.61(7) Å, and the other half are hydrogen-bonded to the nitric acid via the carboxyl group, with an O⋯O distance of 2.59(8) Å.