Vesicles and other bilayered membranous structures can self-assemble from single hydrocarbon chain amphiphiles. Their formation and stability are highly dependent on experimental conditions such as ionic strength, pH, and temperature. The addition of divalent cations, for example, often results in the disruption of vesicles made of a single fatty acid species through amphiphile precipitation. However, membranes composed of amphiphile mixtures have been shown to be more resistant to low millimolar concentrations of divalent cations at room temperature. In this report, several mixtures of amphiphiles are examined for their propensity to self-assemble into membranous vesicular structures under extreme environmental conditions of low pH, high ionic strengths, and temperatures. In particular, mixtures of decylamine with polar cosurfactants were found to efficiently form membranes under these conditions far away from those normally supporting vesicle formation. We further examined decanoic acid/decylamine mixtures in detail. At pH 2 in low ionic strength solutions, the amphiphiles formed oily or crystalline structures; however, the introduction of salts or/and strong acids in conjunction with high temperature induced a stable vesiculation. Thus, extreme environments, such as volcanic or vent environments whose environmental conditions are known to support high chemical reactivity, could have harbored and most significantly promoted the formation of simple organic compartments that preceded cells.

The structure of tetraaqua[2,6-diacetylpyridine bis(semicarbazone)]samarium(III) trinitrate, [Sm(C11H15N7O2)(H2O)4](NO3)3, has monoclinic (P21/c) symmetry. The 2,6-diacetylpyridine (DAPSC) ligand is pentadentate. The coordination of the DAPSC ligand and four coordinated water molecules around the metal cation is best described as a distorted tricapped trigonal prism. The structure displays intermolecular hydrogen bonding. The structure is isomorphous with many other published lanthanide(III) nitrate salts with the DAPSC ligand, 2,6-diacetylpyridinebis(semicarbazone). One of the three nitrate counter-anions is disordered, which is consistent with the structures of other +3 lanthanide nitrate salts with DAPSC. Refinement of occupancies for the disordered nitrate group gave major and minor occupancies of 54.9 (14) and 45.1 (14)%, respectively.