Premium
Effect of Alkali Metal Coordination on Gas‐Phase Chemistry of the Diphosphate Ion: The MH 2 P 2 O 7 − Ions
Author(s) -
Pepi Federico,
Ricci Andreina,
Rosi Marzio,
Di Stefano Marco
Publication year - 2006
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.200500723
Subject(s) - alkali metal , ion , chemistry , inorganic chemistry , gas phase , phase (matter) , organic chemistry
Systematic experimental and theoretical studies on anionic phosphate species in the gas phase are almost nonexistent, even though they could provide a benchmark for enhanced comprehension of their liquid‐phase chemical behavior. Gaseous MH 2 P 2 O 7 − ions (M=Li, Na, K, Rb, Cs), obtained from electrospray ionization of solutions containing H 4 P 2 O 7 and MOH or M salts as a source of M + ions were structurally assayed by collisionally activated dissociation (CAD) mass spectrometry and theoretical calculations at the B3LYP/6‐31+G* level of theory. The joint application of mass spectrometric techniques and theoretical methods allowed the MH 2 P 2 O 7 − ions to be identified as having a structure in which the linear diphosphate anion is coordinated to the M + ion ( I ) and provides information on gas‐phase isomerization processes in the [PO 3 ⋅⋅⋅MH 2 PO 4 ] − clusters II and the [P 2 O 6 ⋅⋅⋅M⋅⋅⋅H 2 O] − clusters IV . Studies of gas‐phase reactivity by Fourier transform ion cyclotron resonance (FTICR) and triple quadrupole (TQ) mass spectrometry revealed that the MH 2 P 2 O 7 − ions react with selected nucleophiles by clustering, proton transfer and addition–elimination mechanisms. The influence of the coordination of alkali metal ions on the chemical behavior of pyrophosphate is discussed.