The Synthesis, Self-Assembled Structures, and Microbicidal Activity of Cationic Gemini Surfactants with Branched Tridecyl Chains

• Published in: Molecules (Basel, Switzerland) Vol. 24; no. 23; p. 4380
• Main Authors: Pisárčik, Martin, Pupák, Matúš, Lukáč, Miloš, Devínsky, Ferdinand, Hubčík, Lukáš, Bukovský, Marián, Horváth, Branislav
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 30.11.2019; MDPI
• Subjects: Aggregation behavior; Anti-Infective Agents - chemical synthesis; Anti-Infective Agents - chemistry; Anti-Infective Agents - pharmacology; Antiinfectives and antibacterials; Aqueous solutions; Atomic properties; Bacteria; Biological properties; Carbon; Cations; Chain branching; Chains; Chemical Phenomena; Chemistry Techniques, Synthetic; Dose-Response Relationship, Drug; Electric Conductivity; Enhanced oil recovery; Gram-negative bacteria; Micelles; Microbial Sensitivity Tests; Microbicides; Molecular structure; Pollutants; Quaternary Ammonium Compounds - chemical synthesis; Quaternary Ammonium Compounds - chemistry; Quaternary Ammonium Compounds - pharmacology; Self-assembly; Solutions; Structure-Activity Relationship; Surface properties; Surface tension; Surface-Active Agents - chemical synthesis; Surface-Active Agents - chemistry; Surface-Active Agents - pharmacology; Surfactants; Yeasts; Zeta potential; gemini surfactant; tridecyl chain; polymethylene spacer; zeta potential; microbicidal activity
• ISSN: 1420-3049; 1420-3049
• DOI: 10.3390/molecules24234380

Cationic gemini surfactants with polymethylene spacer and linear alkyl chains containing an even number of carbon atoms have been extensively studied in the recent past, with the emphasis put on the determination of their aggregation behaviour in aqueous solution and their biological properties. However, the information on the aggregation of branched gemini surfactants with an odd number of carbon atoms in their alkyl chains is only sparsely reported in the literature. To help cover this gap in the research of cationic gemini surfactants, a series of branched bisammonium cationic gemini surfactants with an odd number of carbon atoms in alkyl chains (tridecane-2-yl chains) and a polymethylene spacer with a variable length ranging from 3 to 12 carbon atoms have been synthesized and investigated. Critical micelle concentration, which was determined by three methods, was found to be in the order 10 mol/L. A comparison of the obtained data of the novel series of tridecyl chain geminis with those of gemini surfactants with dodecyl chains and an identical spacer structure revealed that structural differences between both series of gemini surfactants result in different aggregation and surface properties for surfactants with 6 and 8 methylene groups in the spacer ( , '-bis(tridecane-2-yl)- , , ', '-tetramethylhexane-1,6-diaminium dibromide and , '-bis(tridecane-2-yl)- , , ', '-tetramethyloctane-1,8-diaminium dibromide) with the cmc values 8.2 × 10 mol/L and 6.5 × 10 mol/L, respectively, as determined by surface tension measurements. Particle size analysis showed the formation of small stable spherical micelles in the interval between 2.8 and 5 nm and with zeta potential around +50 mV, which are independent of surfactant concentration and increase with the increasing spacer length. Microbicidal activity of gemini surfactants was found to be efficient against Gram-positive, Gram-negative bacteria and yeast.