Comparison of muonium and positronium with hydrogen atoms in their reactions towards solutes containing amide and peptide linkages in water and micelle solutions

• Published in: Canadian journal of chemistry Vol. 67; no. 1; pp. 120 - 126
• Main Authors: Barnabas, Mary V, Venkateswaran, Krishnan, Walker, David C
• Format: Journal Article
• Language: English
• Published: Ottawa, Canada NRC Research Press 01.01.1989; National Research Council of Canada
• Subjects: Chemistry; Exact sciences and technology; General and physical chemistry; Interactions with other particles (positron, muon, ...). Positronium chemistry; Physical chemistry of induced reactions (with radiations, particles and ultrasonics); positronium; Thymine; Cationic surfactant; Benzoquinone; Positron annihilation; Muonium; Thioureas; Quaternary ammonium compound; Orthopositronium; Medium effect; Hydrated electron; Carboxamide; Ureas; Cytosine; Kinetics; Micellar solution; Uracil
• ISSN: 0008-4042; 1480-3291
• DOI: 10.1139/v89-020

Rate constants have been sought for the reaction of muonium (Mu) and o-positronium (Ps) with solutions of thirteen solutes containing the groups. Values of k range from <10 5  M −1  s −1 to 3 × 10 10  M −1  s −1 and show a variety of trends. For instance, Mu adds across the carbonyl group much faster than does H, but abstracts from an adjacent methyl group more slowly. Mu adds exceptionally efficiently to the thiocarbonyl group. Abstraction reactions are identified by large enhancements in reaction rates when localized in micelles. Ps behaves quite differently to the others in neither abstracting nor adding to these compounds, consistent with it not being a pseudo-isotope of hydrogen. Keywords: muonium, positronium, hydrogen, hydrated electrons, micelles.