Premium
Observations of different core water cluster ions Y − (H 2 O) n (Y = O 2 , HO x , NO x , CO x ) and magic number in atmospheric pressure negative corona discharge mass spectrometry
Author(s) -
Sekimoto Kanako,
Takayama Mitsuo
Publication year - 2011
Publication title -
journal of mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.475
H-Index - 121
eISSN - 1096-9888
pISSN - 1076-5174
DOI - 10.1002/jms.1870
Subject(s) - chemistry , ion , mass spectrum , analytical chemistry (journal) , mass spectrometry , cluster (spacecraft) , spectral line , organic chemistry , chromatography , computer science , programming language , physics , astronomy
Reliable mass spectrometry data from large water clusters Y − (H 2 O) n with various negative core ions Y − such as O 2 − , HO − , HO 2 − , NO 2 − , NO 3 − , NO 3 − (HNO 3 ) 2 , CO 3 − and HCO 4 − have been obtained using atmospheric pressure negative corona discharge mass spectrometry. All the core Y − ions observed were ionic species that play a central role in tropospheric ion chemistry. These mass spectra exhibited discontinuities in ion peak intensity at certain size clusters Y − (H 2 O) m indicating specific thermochemical stability. Thus, Y − (H 2 O) m may correspond to the magic number or first hydrated shell in the cluster series Y − (H 2 O) n . The high intensity discontinuity at HO − (H 2 O) 3 observed was the first mass spectrometric evidence for the specific stability of HO − (H 2 O) 3 as the first hydrated shell which Eigen postulated in 1964. The negative ion water clusters Y − (H 2 O) n observed in the mass spectra are most likely to be formed via core ion formation in the ambient discharge area (760 torr) and the growth of water clusters by adiabatic expansion in the vacuum region of the mass spectrometers (≈1 torr). The detailed mechanism of the formation of the different core water cluster ions Y − (H 2 O) n is described. Copyright © 2010 John Wiley & Sons, Ltd.