Self‐assembly and intra‐cluster reactions of erbium and ytterbium bis(2‐ethylhexyl)sulfosuccinates in the gas phase

Abstract

Analysis of the experimental findings suggests that the observed chemical transformations occur within an organized supramolecular assembly rather than in a random association of components. The fragmentation pathways leading to the neutral loss of a fragment of nominal mass 534 Da, assigned as C28 H54 O7 S, from some positively charged aggregates has been rationalized.

Electrospray ion mobility mass spectrometry of positively and negatively charged (1R,2S)‐dodecyl(2‐hydroxy‐1‐methyl‐2‐phenylethyl)dimethylammonium bromide aggregates

“…This finding suggests a different stability of positively and negatively charged aggregates which could be rationalized in terms of bounding linkages with the surfactant counterions (Br – for the cationic DMEB or Na + for the anionic NaAOT and NaOS surfactants) that play in the direction of a stabilizing effect on the aggregates. This is consistent with the experimental and theoretical stability scale obtained for NaAOT aggregates showing that, for this surfactant, positive aggregates are more stable than negative ones …”

“…This is consistent with the experimental and theoretical stability scale obtained for NaAOT aggregates showing that, for this surfactant, positive aggregates are more stable than negative ones. [27][28][29] Another aspect of interest which can be appreciated by looking at the data in Table 1 is the marked difference between the maximum charge state and aggregation numbers reached by single-tailed (DMEB, NaOS) surfactants including the cationic surfactants (hexyl trimethylammonium bromide and decyl trimethylammonium bromide, 6TAB and 10TAB) studied by Borysik and Robinson [11] and double-tailed (NaAOT) surfactants. This implies that the increased steric hindrance due to the presence of two alkyl chains adversely affects the overall stability of the aggregates.…”

Recent Approaches for Chemical Speciation and Analysis by Electrospray Ionization (ESI) Mass Spectrometry

“…This led to a straightforward unambiguous molecular formula and ionic composition determination. Indelicato et al (2014) investigated by ESI-MS, tandem mass spectrometry (ESI-MS-MS), and energy-resolved mass spectrometry (ER-MS) some lanthanide-functionalized surfactants: the ytterbium and erbium salts of bis(2-ethylhexyl)-sulfosuccinate (AOT). Evaluating the cone voltage effect on the metallated surfactant aggregation, they obtained detailed information on the stability and structural features of positively and negatively singly charged metallated species evidencing the formation of very large aggregates containing up to 5 Yb 3+ or Er 3+ ions.…”

Charged supramolecular assemblies of surfactant molecules in gas phase

“…Also the preferential charge state of the aggregates can be tailored by varying the cone voltage (Cacace et al, 2002;Sharon, Ilag, & Robinson, 2007;Bongiorno et al, 2010;Indelicato et al, 2014).…”

“…Moreover, the reactivity and physical properties are changed due to confinement effects and solubilizate-surfactant interactions. Obviously, the judicious choice of the surfactant molecule could help to modulate or amplify some specific effects such as chirality, fluorescence, and complex formation (Colombo et al, 1991;Abbate et al, 2014;Indelicato et al, 2014).…”