Spiral hexatrienes. The hindered cis isomer of mini-carotene-3 and hexakis-(2,2′,4,4′,6,6′-trifluoromethyl)stilbene

A 19F NMR Study of Rhodopsin Analogs: Use of Vinylfluororetinal Chromophores

“…The former includes torsion angles, bond lengths, bond angles, and strong hydrogen bonds, the latter the external electrical charge field generated by vicinal multipoles and weak electrical interactions. Ring currents and other local group anisotropies are believed to exert a small effect, ∼2 ppm shift. , …”

“…The application of 19 F NMR spectroscopy in studying the structure and function of proteins is widely known. 1 In most cases, fluorine is introduced into the protein by using fluorinated amino acid.…”

“…Much useful information on structural properties related to proteinchromophore interactions in rhodopsin have been obtained from electron diffraction, 5 X-ray diffraction, 6 and electron cryomicroscopy studies. 7 Abbreviations used in this paper are as follows: FOS, 19 F NMR opsin shift; OS, opsin shift; PSB, protonated Schiff base; SB, Schiff base.…”

Regiospecific topochemical reactions controlled by trifluoromethyl directing groups

“…This observation is in accordance with reactivity studies involving 1,3-butadienes in solid. 2 In addition, it was noticed, interestingly, that photoisomerization of the CLC bonds in 2 was undetected in solution 16 upon direct irradiation (Pyrex). To unequivocally elucidate the stereochemistry of 2, crystallographic data was obtained (Fig.…”

Helically twisted chiral cyanine dyes: Influence of chromophore length on observed and calculated rotatory strengths

“…(For a related study of helically twisted trienes, we refer to a recent paper by Chen et al 17 ) In order to study the dependence of the chiroptical properties of these compounds on the length of the chromophore, AM1…”