Design, synthesis and evaluation of a series of alkylsiloxane-bonded stationary phases for expanded supercritical fluid chromatography separations was written by Fu, Qing;Jiang, Dasen;Xin, Huaxia;Dai, Zhuoshun;Cai, Jianfeng;Ke, Yanxiong;Jin, Yu;Liang, Xinmiao. And the article was included in Journal of Chromatography A in 2019.Application of 18836-52-7 The following contents are mentioned in the article:
Supercritical fluid chromatog. (SFC) today represents an alternative technique in anal. chem. due to its obvious benefits in kinetic performance and its complementarity to liquid chromatog. In this paper, a series of alkylsiloxane-bonded stationary phases were synthesized and evaluated to expand their SFC applications. Five kinds of non-endcapped C8 stationary phases (C8-1 to C8-5) with increasing bonding d. were synthesized, and the carbon content was 3.91%, 6.07%, 7.97%, 8.65% and 9.10% resp. Retention mechanism of the C8 phases in SFC in SFC was investigated by the use of a linear solvation energy relationship (LSER) model. Results underlined a close relationship between the bonding d. of alkyl chain and the dispersion and polar interactions of the stationary phase. Complementary evaluation was studied based on the calculation of vector angle (θ), and the widest θ of 123° was found between silica and C8 with the highest bonding d. Selective diversity also existed between the two C8 phases with the highest and lowest bonding densities. In addition, the effect of modifier on the SFC mechanism was investigated. Modifiers (methanol, ethanol, isopropanol and acetonitrile) had insignificant influence on the dispersion interaction but they mainly affected the hydrogen bonding interaction by changing the LSER parameters a and b. Finally, C8 and silica columns were applied for separation of eight amide alkaloids of Piper kadsura. Silica provided better retention but limited selectivity while C8 can distinguish alkaloids different in alkyl chain, double bond and cis-trans structure. This research further contributed to demonstrate the potential of alkylsiloxane-bonded stationary phase in improving selectivity of SFC. This study involved multiple reactions and reactants, such as (2E,4E)-N-Isobutyldeca-2,4-dienamide (cas: 18836-52-7Application of 18836-52-7).
(2E,4E)-N-Isobutyldeca-2,4-dienamide (cas: 18836-52-7) belongs to amides. Amides are pervasive in nature and technology. Proteins and important plastics like Nylons, Aramid, Twaron, and Kevlar are polymers whose units are connected by amide groups (polyamides); these linkages are easily formed, confer structural rigidity, and resist hydrolysis. The presence of the amide group –C(=O)N– is generally easily established, at least in small molecules. It can be distinguished from nitro and cyano groups in IR spectra. Amides exhibit a moderately intense νCO band near 1650 cm−1. By 1H NMR spectroscopy, CONHR signals occur at low fields. In X-ray crystallography, the C(=O)N center together with the three immediately adjacent atoms characteristically define a plane.Application of 18836-52-7
Referemce:
Amide – Wikipedia,
Amide – an overview | ScienceDirect Topics