2083-68-3Relevant articles and documents
Photoprocesses on Colloidal Clay Systems. 2. Quenching Studies and the Effect of Surfactants on the Luminescent Properties of Pyrene and Pyrene Derivatives Adsorbed on Clay Colloids
DellaGuardia, R. A.,Thomas, J. K.
, p. 3550 - 3557 (1983)
The cationic fluorescent probe trimethylammonium bromide (PN+) is adsorbed by the colloidal particles of the clay minerals montmorillonite and kaolin.The emission spectrum, polarization of fluorescence measurements, and transient fluorescence decay characteristics of PN+ are used to study the nature of its adsorbed state.Quaternary ammonium surfactants of varying hydrocarbon chain length cause a rearrangement of the PN+ molecules on the surface and decrease its interaction with the mineral surface.Quenching studies with nonionic andcationic molecules indicate that diffusion on the surface of montmorillonite is reduced below that observed in aqueous solution while the apparent rates obtained with kaolin particles are increased.Montmorillonite particles with a surfactant bilayer surrounding their surfaces are formed by the addition of an excess amount of surfactant to the colloid.The emission spectrum and the steady-state quenching studies yield information on the location of pyrene on these particles, as well as on the nature of the colloidal particles.
Synthesis, characterization and conductivity of quaternary nitrogen surfactants modified by the addition of a hydroxymethyl substructure on the head group
Jordan, Deborah,Tan, Eng,Hegh, Dylan
, p. 587 - 592 (2012/10/29)
Two novel series of hydroxymethyl group-appended quaternary nitrogen surfactants (QNSs) based on the aliphatic N-alkyl-trimethylammonium and aromatic N-alkylpyridinium head groups were synthesized from the appropriate nitrogen head group precursor and 1-bromoalkane. The QNSs were characterized using 1H and 13C nuclear magnetic resonance and infrared spectroscopy, and their purity confirmed using elemental analysis. The solution behavior of the QNSs was investigated by conductivity, assessing both the aggregation concentration as well as the amount of counter-ion dissociation. The results showed a general decrease in the aggregation concentration for the compounds with the hydroxymethyl addition, where the pyridinium compounds were more affected than the ammonium QNSs. In contrast, the extent of counter-ion dissociation (α) from the aggregate was slightly increased for the ammonium compounds but that of the pyridinium compounds was not generally affected by the structural modification.
Odd-even effect and unusual behavior of dodecyl-substituted analogue observed in the crystal structure of alkyltrimethylammonium-[Ni(dmit) 2]- salts
Dai, Kotaro,Nomoto, Kuniharu,Ueno, Shinji,Tomono, Kazuaki,Miyamura, Kazuo
experimental part, p. 312 - 319 (2011/05/13)
A series of [Ni(dmit)2]- (dmit: 1,3-dithiole-2- thione-4,5-dithiolato) salts of alkyltrimethylammonium (Cn: n represents the alkyl chain length; n = 3 and 518) have been prepared and analyzed by X-ray structural analysis. All complex salts have been found to be composed of alternate sheets of [Ni(dmit)2]- anions and sheets of cations with a pronounced interdigitation of the alkyl chains. However, molecular arrangement differed between (C3)[Ni(dmit)2] and other (Cn)[Ni(dmit)2] (n = 518). Adjacent cations were aligned along the long axis of [Ni(dmit)2]- anion in C3 complex salt, while in others (C5-C18 complex salts), they were aligned toward the short axis. Such a difference in arrangement arose from correlativity between the lengths of the long axis of cation and anion, namely CLCA. Furthermore, relative orientation between the alkyl chain of cation and [Ni(dmit)2]- anion differed between the odd- and even-numbered cations for C10-C18. Whereas the plane of alkyl chain for odd-numbered cation was normal to the plane of [Ni(dmit)2]- anion, that of even-numbered cation was parallel. It was also found that C12 analog behaved like odd-numbered cations. However, in C12 salt, the end methyl group of the dodecyl group adopted unusual end-gauche conformation.
