Alkyltrimethylammonium cations

The Effects of Complexing Agents. Cai et al.66 replaced the sodium counterion of MX-DNA with various aliphatic amine cations, e.g. spermine cation, and alkyltrimethylammonium cation as well as polymeric amine cations, such as poly-L-lysine and polyethylenimine to vary the separation between DNA duplexes. The radiation-produced electrons from the complexing agents readily transfer to the more electron affinic DNA. 

A variation of the receptor polarization effect is the binding strategy shown by schematic Complex 9. In this case the binding of an ion to one face of an appropriately designed receptor polarizes (and perhaps preorganizes) the receptor so that it can bind the counterion to the opposite face with increased affinity. Two examples that use this strategy are the macrocyclic phosphine oxide 10, which can simultaneously bind a monoalkylammonium cation and Cf J " and the cyclopeptide 11, which simultaneously binds an alkyltrimethylammonium cation and tosylate anion " (Chart 2). 

In the alkyltrimethylammonium cation series (of which tetramethylammonium is the foundation member) maximal activity is reached at the n-pentyltrimethylammonium salts which are about eight times as active as acetylcholine (and about as active as nicotine) at nicotinic receptors (Willey, 1955). D-Lactoylcholine has strong nicotinic, but little muscarinic, potency (Sastry, Lasslo and Pfeiffer, 1960). Phenolic ethers of choline, such as (12.86), have a strong nicotinic (but little muscarinic) activity (Hey, 1952). However, this ratio is reversed by inserting methyl-groups into the two or/Ao-positions of the benzene ring, a reminder that nicotinic action is easily repressed by steric hindrance to which muscarinic action is indifferent (note the effect of the C-methyl-group in methacholine, p. 523). 

The synthesis of M41S-type materials can be carried out under hydrothermal conditions using alkyltrimethylammonium cations C TMA" as structure-directing agents and tetraethoxysilane (TEOS) as silica source. Similarly to the lyotropic phases formed in surfactant-water mixtures, the surfactants form micellar structures. Their self-assembly is strongly influenced by the presence of silicate anions which form by the hydrolysis of TEOS. After the synthesis, the space in between the surfactant micelles is filled by silica which develops by polycondensation of the silicate anions and which forms walls of a thickness of ca. 8 A [3,4]. 

Other studies have shown that a related mesoporous silicate can be formed via hydrothermal treatment of a layered silicate such as kanemite and the same alkyltrimethylammonium cationic surfactants [31, 32]. Variation of the synthesis conditions results in a fairly ordered porous material denoted as FSM-16 that has physical properties and diffraction data similar to that of MCM-41 [32]. 

PolyCa, L-Glutamic Acid)-Alkyltrimethylammonium Cation Complexes... 

Figure 15 Chemical structures of (a) poly(Qf,L-glutamic acid)-alkyltrimethylammonium cation complexes and (b) poly(L-lysine)-alkyl sulfate anion complexes.

Seki S, Tsuzuki S, Hayamizu K, Serizawa N, Ono S, Takei K, Doi H, Umebayashi Y (2014) Static transport properties of alkyltrimethylammonium cation-based room-temperature ionic liquids. J Phys Chem B 118 4590-4599... 

Bambagiotti-Alberti, M., S. A. Coran, F. Benvenuti, R LoNostro, S. Catinella, D. Favretto, P. Traldi, Decomposition channels alternative to remote-charge fragmentations observed in MS of alkyltrimethylammonium cations, 7. Mass Spectrom., 1995,50,1742-1746. 

The fact that f.a.b.-m.s. can be used to observe cluster ions has been exploited in a study of metal binding to cyclodextrins, and in an investigation of the complexes formed between a 3-O-methylmannose dodecasac-charide and alkyltrimethylammonium ions having decyl and hexadecyl as alkyl chains. In the latter study, the larger organic cation was shown to form the stronger complex. 

Smaller, hard cations, such as alkyltrimethylammonium salts and crown ether-cation complexes, will promote the elimination of dichlorocarbene to form a hard ion pair of type Q+C1 . 

Measurement of K for NBF from solution of four homologues of the cationic surfactants alkyltrimethylammonium chlorides [488] indicated that K decreased with increasing surfactant alkyl chain length. 

D) (Cationics) Alkyltrimethylammonium bromides [49] supplied by Sigma (France) and used as received (99% purity) ... 

Zirconia. Mesoporous zirconia was first reported by Knowles and Hudson with cationic alkyltrimethylam-monium surfactants. Starting from zirconium sulfate or propoxide, Schiith and Ciesla et al. synthesized hexagonal mesoporous zirconia using alkyltrimethylammonium surfactants as templates. Reddy and Sayari obtained hexagonal or lamellar phases of mesostructured zirconia using quaternary ammonium surfactants and acidified primary alkylamine. 

Phenolate resorcin[4]arenes of the type IV-1 (Scheme 12.15) are efficient hosts for organic ammonium ions in protic solvents in strongly alkaline organic media by simultaneous charge-charge and cation- r interaction. A drawback of receptors such as IV-2 is the low selectivity towards alkyltrimethylammonium and bulkier tetraalkylam-monium ions. ... 

Mesoporous organosilicates are synthesized using similar self-assembly approaches as pure silica meso-phases the main difference being the silicon-containing precursors that consist of bridged silsesquioxanes, (RO)3Si-R -Si(OR)3. Different types of amphiphile molecules, including cationic (alkyltrimethylammonium),... 

CE is a separation technique that may be an alternative to LC to determine alkyl chain distribution of anionic and cationic surfactants. Most of the studies refer to alkylbenzyldimethylammonium with UV absorbance detection (Figure 2). Other uses of CE include the separation of homologs of anionic surfactants (as AS) and cationic (as alkyltrimethylammonium) by isotachophoresis with conductometric detection and homologs of non-UV absorbing surfactants (AS, alkylsulfonate, alkylsarcosinates and dialkyldimethylammonium) by capillary zone electrophoresis using indirect detection. 

This reaction scheme was first observed by Kharasch and Read [40], but no industrial application has yet been developed because of poor yield and selectivity with linear parafQns. The yield of alkyl chlorides may be higher than that of sulfochlorides [23]. However, some recent works have shown that in the presence of an adequate catalyst (e.g., pyridine) for rather low conversion rates (e.g., 15%), sulfuryl chloride can lead to acceptable RSOjCl/RCl ratio (about 1 in pure phase and higher in benzene solvent) and the quasi absence of di- and polysubstituled compounds [39-45]. Without doubt, the main drawback of the process is still the large amount of alkyl chlorides produced it is then necessary to consider the possible recovery and transformation of the chloroalkane mixtures through quatemization into alkyltrimethylammonium chlorides (cationic surfactants) [46,47] ... 

In this work, a good deal of information on the adsorption properties from two kinds of cationic surfactants (alkylpyridinium and alkyltrimethylammonium) have been obtained by combining SERS measurements and vibrational calculations based on Hartree-Fock methods. 

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