Structure of p-cyanobenzoic acid

Conformational differentiation of α‐cyanohydroxycinnamic acid isomers: a Raman spectroscopic study

“…These confirm that indeed both structural isomers form –COOH dimers, provided that the carboxyl group is not deprotonated. This is consistent with the published X‐ray crystal structure of CHCA4, which clearly exhibits dimerization of its carboxylic acid group . Varying the pH of the solutions also revealed that the –COOH group of CHCA4 has a higher p Ka than that of CHCA3.…”

“…This is consistent with the published X-ray crystal structure of CHCA4, which clearly exhibits dimerization of its carboxylic acid group. [17,18,26,27] Varying the pH of the solutions also revealed that the -COOH group of CHCA4 has a higher pKa than that of CHCA3. This was evident because the Raman spectra of CHCA4 at pH 1 and 7 are clearly very similar, indicating that the functional group is similarly protonated at pH 7 as at pH 1, while that for CHCA3 show an obvious difference.…”

“…[13,14] The larger presence of CHCA4 in biological studies has also led to its use as a scaffold for the development of novel small molecule inhibitors to protein activity such as those of aldose reductase. [14] Our laboratory's recent study on CHCA3 and CHCA4 conjugated to the amyloidogenic hIAPP [22][23][24][25][26][27][28][29] showed slightly different aggregation behaviour, which perhaps can be attributed to the slight difference in structure that brings about different chemical properties between the two positional isomers. [15] We measured the Raman spectra of the two isomers and assigned the observed peaks based on DFT calculations and by comparison to literature spectra of similarly structured compounds.…”

The Crystal and Molecular Structures of Three Homologous, Mesogenic Trans, Trans-4'-Alkylbicyclohexyl-4-carbonitriles (Cyclohexylcyclohexanes, CCHs)

“…It is obvious that the standard deviations of all bond lengths and bond angles of CCH7 are somewhat greater than those of CCHS and CCH3, these being dependent upon the accuracy of the refinement. (2) 0.5274 -0.150 (6) 0.229(2) 0.5031 -0.268 (7) 0.190(2) 0.5500 -0.139 (6) 0.020(2) 0.5739 -0.014 (7) 0.059(2) 0.5676 -0.504 (7) 0.06M1(2) 0.5899 -0.373(7) -0.0240 (2) 0.109(2) 0.6392 -0.391 (7) 0.6171 -0.261 (7) 0.6519 -0.783 (7) 0.6319 -0.646 (7) 0.634 ( Nonetheless, all the bond lengths and bond angles of the three compounds referred to here are equivalent, when one considers the appropriate standard deviations, as well as excluding the N-C( 1) and C( 1)-C(2) bond lengths of CCH7. Likewise the N-C(1)-C (2) bond angle of this compound has to be neglected.…”

4,4′-(1,2,4,5-Tetrazine-3,6-diyl)dibenzonitrile

“…For synthesis details, see: Spychała et al (1994Spychała et al ( , 2000. For related structures and discussion, see: Higashi & Osaki (1981); Infantes et al (2003).…”