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Chiral Carboxylic Acids (chiral + carboxylic_acid)
Selected AbstractsChiral carboxylic acids and their effects on melting-point behaviour in co-crystals with isonicotinamideACTA CRYSTALLOGRAPHICA SECTION B, Issue 6 2008Andreas Lemmerer The crystal structures of co-crystals of two systems of chiral carboxylic acids, optically active and racemic 2-phenylpropionic acid and 2-phenylbutyric acid, with isonicotinamide are reported to investigate the effects of the chirality of the chiral carboxylic acids on the melting point of the co-crystal complexes. It was found that the racemic co-crystal has a higher melting point than the optically active co-crystal, which correlates with the denser packing arrangement inherent in centrosymmetric space groups. [source] Determination of the enantiomeric excess of chiral carboxylic acids by 31P NMR with phosphorylated derivatizing agents from C2 -symmetrical diamines containing the (S)-,-phenylethyl groupCHIRALITY, Issue 6 2007Virginia M. Mastranzo Abstract The use of P(III) and P(V) organophosphorus derivatizing agents prepared from C2 symmetrical (1R,2R)- and (1S,2S)- trans - N,N,-bis-[(S)-,-phenylethyl]-cyclohexane-1,2-diamines 1 and 2, as well as (1R,2R)- and (1S,2S)- trans - N,N,-bis-[(S)-,-phenylethyl]-4-cyclohexene-1,2-diamines 3 and 4 for the determination of enantiomeric composition of chiral carboxylic acids by 31P NMR, is described. Chirality, 2007. © 2007 Wiley-Liss, Inc. [source] | ||||||||||