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Chirality‐directed self‐assembly of supramolecular propellers of dialkyltartrate trimers with hydronium, ammonium and primary aminium ions in CI mass spectra
Author(s) -
Johann Winkler F.,
Medina Ramiro,
Winkler Johannes,
Krause Helmut
Publication year - 1997
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/(sici)1096-9888(199711)32:10<1072::aid-jms561>3.0.co;2-9
Subject(s) - chemistry , supramolecular chemistry , hydronium , mass spectrum , chirality (physics) , ion , ammonium , primary (astronomy) , crystallography , stereochemistry , organic chemistry , crystal structure , nambu–jona lasinio model , chiral symmetry breaking , physics , quantum mechanics , quark , astronomy
The specific non‐covalent gas phase association of chiral dialkyltartrates M with multiprotic onium ions A · H + , such as hydronium, ammonium and primary aminium ions, was investigated by chemical ionization (CI) mass spectrometry. The method applies enantiomer‐labeled racemates of dimethyl‐(S)‐ and [ 2 H 6 ]dimethyl‐(R)‐tartrate (s and r) and diisopropyl‐(S)‐ and [ 2 H 14 ]diisopropylyl‐(R)‐tartrate (S and R). Unusually stable trimer adduct clusters M 3 · AH + were observed (5%–50% of the substrate ions). The abundances of the four diastereomers rrr · AH + , rrs · AH + , rss · AH + and sss · AH + did not show the statistics 1:3:3:1, but a pattern ranging from 1:1:1:1 to 5:3:3:5. Thus the homochiral clusters rrr · AH + and sss · AH + are three to five times more favored than the heterochiral ions. For the primary amines 1–10 as base A the chiral effect mainly depends on the CI conditions and hardly on the amine properties (proton affinity, steric crowding, chirality). For ammonia and water as base A the chiral effect was 2.1 and 2.7–3.6 respectively. The effect was not found in M 3 · AH + with diprotic onium ions from alcohols and secondary amines. It is assumed that the homochiral clusters M 3 · AH + have an especially stable supramolecular propeller structure as supported by PM3 calculations. The clusters allow CI experiments for molecular and chiral recognition. © 1997 John Wiley & Sons, Ltd.