Imidazoline derivatives characterization

As mentioned above, most commercial products are based on either a lauric (mainly C-12) or a whole coconut distribution (C-8 to C-18, with approximately 50% C-12) since these alkyl distributions give the best detergency. Early on, the imidazoline derived amphoterics were characterized as exceptionally mild to the skin and eyes relative to most surfactants available at the time. This made them excellent candidates for use in baby shampoos, geriatric cleansing products, hand wash for medical facilities and so on. 

Several chiral PCN pincer Pd(n) complexes with aryl-based aminophosphine-imidazolines have been reported by Gong and co-workers. The complexes were prepared by a two step synthetic strategy, starting from the corresponding aminophenyl-imidazoline derivatives which upon reaction with disubstituted chlorophosphines, yielded the aminophosphines 45a-c. Further complexation with PdClz gave the Pd(n) pincer complexes 46a-c (Scheme 10), which were characterized by elemental analysis and H, C, and P 1H NMR. 

Characterization of an imidazoline-derived amphoteric requires considering the reaction pathway used to prepare the compound. For example, an amidobetaine may be made by sodium chloroacetate treatment of the imidizoline/linear amide mixture obtained by reacting a fatty acid or ester with iV-hydroxyethylethylenediamine. Possible compo-... 

The only cationic surfactant (Fig. 23) found in any quantity in the environment is ditallow dimethylammonium chloride (DTDMAC), which is mainly the quaternary ammonium salt distearyldimethylammonium chloride (DSDMAC). The organic chemistry and characterization of cationic surfactants has been reported and reviewed [330 - 332 ]. The different types of cationic surfactants are fatty acid amides [333], amidoamine [334], imidazoline [335], petroleum feed stock derived surfactants [336], nitrile-derived surfactants [337], aromatic and cyclic surfactants [338], non-nitrogen containing compounds [339], polymeric cationic surfactants [340], and amine oxides [341]. 

The broader subject of the interaction of stable carbenes with main-group compounds has recently been reviewed. Accordingly, the following discussion focuses on metallic elements of the s and p blocks. Dimeric NHC-alkali adducts have been characterized for lithium, sodium, and potassium. For imidazolin-2-ylidenes, alkoxy-bridged lithium dimer 20 and a lithium-cyclopentadienyl derivative 21 have been reported. For tetrahydropyrimid-2-ylidenes, amido-bridged dimers 22 have been characterized for lithium, sodium, and potassium. Since one of the synthetic approaches to stable NHCs involves the deprotonation of imidazolium cations with alkali metal bases, the interactions of alkali metal cations with NHCs are considered to be important for understanding the solution behavior of NHCs. 

Regarding the importance of these compounds in various fields of biochemistry, many remarkable reactions have been outlined for the formation of other valuable derivatives. The synthesis of imidazolines begins with the addition of isocyanic acid or thiocyanic acid, as described by Huber and coworkers and Garcia Gonzalez and coworkers. Thiocyanic acid is especially well suited for a direct and easy characterization of the Amadori compounds. A reaction time of 2-3 hours results in a 60-70% yield. 

Isoelectric point. Trne amphoteric snrfactants are characterized by their ability to vary their net charge, according to pH conditions. Compared to betaines, which have a permanent positive charge on the qnaternized nitrogen atom, trne amphoterics have both a carboxyl- and an amine gronp that can be protonated. Amphoterics derived from imidazoline can exist in anionic (alkaline conditions), cationic (acidic conditions), or zwitterionic form (aronnd the isoelectric point at pH 5.3). 

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