A simple model for metal cation-phosphate interactions in nucleic acids in the gas phase: alkali metal cations and trimethyl phosphate.
J Am Soc Mass Spectrom
; 19(2): 305-14, 2008 Feb.
Article
em En
| MEDLINE
| ID: mdl-18409209
ABSTRACT
Threshold collision-induced dissociation techniques are employed to determine the bond dissociation energies (BDEs) of complexes of alkali metal cations to trimethyl phosphate, TMP. Endothermic loss of the intact TMP ligand is the only dissociation pathway observed for all complexes. Theoretical calculations at the B3LYP/6-31G* level of theory are used to determine the structures, vibrational frequencies, and rotational constants of neutral TMP and the M+(TMP) complexes. Theoretical BDEs are determined from single point energy calculations at the B3LYP/6-311+G(2d,2p) level using the B3LYP/6-31G* optimized geometries. The agreement between theory and experiment is reasonably good for all complexes except Li+(TMP). The absolute M+-(TMP) BDEs are found to decrease monotonically as the size of the alkali metal cation increases. No activated dissociation was observed for alkali metal cation binding to TMP. The binding of alkali metal cations to TMP is compared with that to acetone and methanol.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Organofosfatos
/
Espectrometria de Massas
/
Cátions
/
Metais Alcalinos
/
Modelos Químicos
Idioma:
En
Revista:
J Am Soc Mass Spectrom
Ano de publicação:
2008
Tipo de documento:
Article
País de afiliação:
Estados Unidos