Vibrational predissociation spectroscopy of the H2-tagged mono- and dicarboxylate anions of dodecanedioic acid

Vibrational predissociation spectroscopy of the HOOC(CH2)(10)COO- and -OOC(CH2)(10)COO- anions is carried out by predissociation of weakly bound H-2 molecules. The HOOC(CH2)(10)COO- (H-2)(2) and -OOC(CH2)(10)COO- (H-2)(10) cluster ions are formed by H-2 attachment to the electrospray-generated bare ions in an ion trap cooled to below 20 K using a closed cycle helium cryostat. The photofragmentation behavior indicates that the H-2 binding energy is about 600 cm(-1), which is similar in strength to that found in Ar-tagged ions. The spectra indicate that the monoanion adopts a cyclic structure through the formation of an asymmetrical, internal anionic H-bond. (C) 2010 Elsevier B.V. All rights reserved.