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Reaction diastereoselectivity of chiral aminoalcohols/[Co(II)NO 3 ] + complexes in evaporating ESI nanodroplets: new insights from a joint experimental and computational investigation
Author(s) -
Aschi Massimiliano,
Fraschetti Caterina,
Filippi Antonello,
Speranza Maurizio
Publication year - 2009
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.1577
Subject(s) - chemistry , adduct , electrospray ionization , fragmentation (computing) , dissociation (chemistry) , molecular dynamics , computational chemistry , ionization , electrospray , mass spectrometry , solvent , ion , stereoselectivity , organic chemistry , chromatography , computer science , catalysis , operating system
The nature of the ionic species, formed by electrospray ionization (ESI) of Co(NO 3 ) 2 /CH 3 OH solutions with a pair of aminoalcohols W and Y, has been investigated by mass spectrometric and computational methods. Collision induced dissociation (CID) of ions, formally corresponding to the [WYCoNO 3 ] + structures, yields fragmentation patterns which reflect not only the expected [WYCoNO 3 ] + connectivity but also that of other isomeric structures. Formation of these latter species is observed only in the presence of a tertiary aminoalcohol, like N ‐methylpseudoephedrine. The CID patterns are found to be strongly dependent on the chemical form (whether the free aminoalcohol or its hydrochloride), the configuration, and the relative concentration of the W and Y aminoalcohols. This variability parallels the results of classical MD (molecular dynamics) simulations of the [WYCoNO 3 ] + adducts which show a drastic alteration of the mechanical–dynamical features of the adducts by simply changing the charge state of W and/or Y, their absolute configuration, or by removing the solvent. The present experimental and computational study confirms the observation of fast stereoselective reactions in ESI nanodroplets before their evaporation and warns against any automatic correlation between the ESI spectrum of an analyte and its structure in solution. Copyright © 2009 John Wiley & Sons, Ltd.