Phase transitions and molecular motions in a model biomembrane (C12H25NH3)2SnCl6

Nuclear magnetic relaxation by regularly distributed dense paramagnetic ions in a quasi-two-dimensional system

“…Thus, the ammonium (NH 3 ) group may be too close to the magnetic layer to be reflected in T 21 1L ; but should be reflected by the T 21 1S component. The activation energies were obtained to be 10^1.5 and 24^3 kJ/mol for the methyl groups, comparable to those of the methyl groups in similar compounds [7,8,10]. The protons in the methyl (CH 3 ) group in CnMn are located farthest from the magnetic layers, midway between them.…”

“…In the case that M is a nonmagnetic ion, nuclear magnetic resonance (NMR) has been extensively used to study the phase transitions [7 -9]. In particular, 1 H NMR has been successfully applied for the study of thermal and critical fluctuations in the organic layers representing model membranes [10,11]. 1 H NMR studies of CnMn are very few and confined to the two-dimensional magnetism, which can be attributed to the fact that 1 H NMR has been believed to be dominated by the electron spins in the paramagnetic system, and thus not to be suitable for the study of the organic layers representing a model membrane.…”

Distinct critical fluctuations and molecular motions manifest in a model biomembrane

“…In our previous 1 H NMR studies of the CnSn systems, two typical successive phase transitions were observed [4][5][6][7]: (a) order-disorder transition of the rigid alkyl chains accompanied by a uniaxial reorientation about their long axes along with the flipping of the polar groups, such as NH 3 , between the potential wells, and (b) conformational transition leading to a partial melting of the alkyl chain part. In the low temperature (LT) phase below the order-disorder transition temperature, the alkyl chains are rigid and adopt an all-trans conformation.…”

“…In contrast to the case of bis-n-alkylammonium tetrachlorometallates (n-C n H 2nC1 NH 3 ) 2 MCl 4 with MZCd, Cu, Mn and Zn (CnM) [13][14][15][16][17], little information is available on the phase transitions in CnSn [4][5][6][7][18][19][20]. The first systematic studies on the layer structure intercalation compounds including C10Cd were made by Blinc and coworkers using magnetic resonance.…”

Investigation on Phase Transitions and Thermodynamic Properties of 1-Dodecylamine Hydrochloride (C12H25NH3Cl)(s) by an Improved Adiabatic Calorimeter

“…Therefore, investigations on a solid-state phase change in all kinds of energy storage materials are most frequently conducted as a result of the wide applications of these materials. The bis(n-alkylammonium) halometallates(II) (abbreviated as C 12 M) [1][2][3][4] are important organometallic compounds of the general formula (C 12 H 25 NH 3 ) 2 MX n (n = 4 or 6), where M is a divalent or trivalent metal ion and X is a negative haloid ion. They are characterized by a high enthalpy change and excellent reversibility of a solidto-solid phase transition between two polymorphic forms in the temperature range 273 K to 393 K. As the necessary intermediate or raw material, 1-dodecylamine hydrochloride (C 12 H 25 NH 3 Cl) plays an important role in the formation of C 12 M in which the C 12 H 25 NH + 3 cation bonds with the MX 2− n anion through ionic bonds.…”