1. Acid-ammonium heterodimer and n (ammonium)-h...N (pyridine) synthon preference in three salts of nicotinic acid with (1r,2r)-1,2-diphenylethylenediamine.
Peng Zhang, Hongyu Guan, Yang Han, Fang Guo, Qiang Fu. Acta Crystallogr B Struct Sci Cryst Eng Mater. 2019 Apr 1; 75(Pt 2): 219-226. DOI: 10.1107/S2052520619000477. PMID: 32830747.
Nicotinic acid (NA), known as vitamin B3, has been widely studied in pharmaceutical science. Herein, three salts derived from NA and (1R,2R)-1,2-diphenylethylenediamine (DPEN), including one solvent-free salt (DPEN)(NA)2and two solvated salts, (DPEN)(NA)2(EA) and (DPEN)(NA)2(ACN) (EA: ethyl acetate, ACN: acetonitrile), have been obtained and characterized by solid-state techniques. By the investigation of single-crystal structures, the synthons, acid-ammonium heterodimer and Nammonium-H...Npyridinebetween functional groups of 1,2-diphenylethylenediammonium and NA are revealed and further identified using Hirshfeld surface analysis. The utility of the synthons is further demonstrated by making salts with the NA isomer, isonicotinic acid. Here the synthon occurrences in cocrystals/salts of NA (including NA derivatives) and diamine coformers reported in the Cambridge Structure Database (CSD) are compared. The robustness of acid-ammonium heterodimer and Nammonium-H...Npyridineis investigated by a search of the CSD. The NA salts also show their improved solubility in pH 1.2, 4.5 and 6.8 buffer mediums compared with pure NA material.
2. Preparation and enantioseparation of a mixed selector chiral stationary phase derived from benzoylated tartaric acid and 1,2-diphenylethylenediamine.
Wei Chen, Zheng-Wu Bai, Shi-Rong Li, Wen-Juan Wei, Hui-Wen Deng. Chirality. 2010 Jun; 22(6): 604-11. DOI: 10.1002/chir.20799. PMID: 19899156.
L-Dibenzoyl tartaric acid was mono-esterified with benzyl alcohol, and then chlorinated with SOCl(2) to give (2S,3S)-1-(benzyloxy)-4-chloro-1,4-dioxobutane-2,3-diyl dibenzoate (Selector 1). (1R,2R)-1,2-Diphenylethylenediamine was mono-functionalized with phenyl isocyanate and phenylene diisocyanate in sequence to give (1R,2R)-1,2-diphenyl-2-(3-phenylureido)ethyl 4- isocyanatophenylurea (Selector 2). Two brush-type chiral stationary phases (CSPs) of single selector were prepared by separately immobilizing selectors 1 and 2 on aminated silica gel. Selectors 1 and 2 were simultaneously immobilized on aminated silica gel to give a mixed selector CSP. The enantioseparation ability of these CSPs was studied. The CSP of selector 1 has strongest separation ability, while the enantioseparation ability of the mixed selector CSP is relatively lower.
3. Tuning mechanism in a two-component columnar host system composed of 1,2-diphenylethylenediamine and 1,1'-binaphthyl-2,2'-dicarboxylic acid.
Kakuhiro Kawaguchi, Tomohiro Sato, Yoshitane Imai, Yoshio Matsubara, Katuzo Murata, Reiko Kuroda. Org Lett. 2008 Feb 7; 10(3): 469-71. DOI: 10.1021/ol7028433. PMID: 18183998.
In a two-component columnar host system composed of racemic (rac)-1,2-diphenylethylenediamine and rac-1,1'-binaphthyl-2,2'-dicarboxylic acid, a cavity tuning mechanism resulted from changes in the structure of the columns using a specific combination of the following four molecules: (1R,2R)-1, (1S,2S)-1, (R)-2, and (S)-2.
