In solution phase, the compounds having arylidene-hydrazide structure (-C=N-NH-C=O) may exist, depending on the solvent, as Z geometrical isomers
around -C=N- bond and as cis and trans amide rotomers (conformers) around amide N-H single bond [33-36].
Madala, "Revising reverse-phase chromatographic behavior for efficient differentiation of both positional and geometrical isomers
of dicaffeoylquinic acids," Journal of Analytical Methods in Chemistry, vol.
Geometrical Isomers. Two geometrical isomers were obtained for Na[Co[([L.sub.1]).sub.3]] and Na[Co[([L.sub.2]).sub.3]].
According to Greenwood and Earnshaw (1997), the UVVis spectra of geometrical isomers are often diagnostic.
Trifunovic, "The geometrical isomers of oxalato and malonato-(ethylenediamine-N,N'-di-S,S-2-propionato)-chromate(III) complexes," Journal of the Serbian Chemical Society, vol.
The complex [sup.1]H NMR spectra show that the uranyl complexes have two conceivable geometrical isomers. The photodegradation property of the target complexes was investigated by the RhB which is a model compound of organic pollutant.
Nakano, "Identification of geometrical isomers using vibrational circular dichroism spectroscopy: a series of mixed-ligand complexes of diamagnetic Co(III) ions," Dalton Transactions, vol.
A column temperature study was conducted using a longer LC program (45 mins) to enhance the separation of diCQA geometrical isomers. The column oven temperature was set at 30, 35, 40, 45, 50, 55, and 60[degrees]C.
The Effect of Column Chemistry on the Separation of diCQA Geometrical Isomers. The results show that the chromatographic profile for the UV-irradiated sample of 1,3-diCQA is consistent on both the bi-phenyl and [C.sub.18] column matrices (Figure 2(a)) and consistent with the results achieved by Clifford et al.
Like Nitro, PFP separates geometrical isomers
as well as diastereomers.
Most importantly, the ISCID method was optimized to result in a more stable m/z 191 ([Q.sub.1]) in order to generate this ion upfront inside the source because it was noted, from our preliminary results, that it was ubiquitous in all regional and geometrical isomers. All the acquisition and analysis of data were controlled by Waters MassLynx v4.1 software (SCN 704).
All the annotated CGA molecules in this study, that is, 4-CQA, 4-pCoQA, and 4-FQA, show two ion peaks in their chromatographic separation (Figure 3), which is an indication for the presence of geometrical isomers (trans and cis).