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Search for "cis/trans isomerization" in Full Text gives 34 result(s) in Beilstein Journal of Organic Chemistry.
Amino-substituted diazocines as pincer-type photochromic switches
Beilstein J. Org. Chem. 2013, 9, 1–7, doi:10.3762/bjoc.9.1
- as directed motion at the molecular level [2][3], the geometry change and the force induced during cis–trans isomerization has to be coupled to the environment. In the macroscopic world, therefore, machines are made from stiff materials. Azobenzene, however, is a rather floppy molecule. Both phenyl
Partial thioamide scan on the lipopeptaibiotic trichogin GA IV. Effects on folding and bioactivity
Beilstein J. Org. Chem. 2012, 8, 1161–1171, doi:10.3762/bjoc.8.129
- /trans isomerization can be phototriggered by irradiation at about 260 nm [absorption maximum of the -C(=S)NH- π→π* electronic transition]. (iii) It may act as a minimalist, effective quencher for any type of protein and nonprotein fluorophores. Recently, based on the aforementioned characteristics of
- ][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39][40][41][42][43][44]. Among these properties, we highlight the following: (i) The thioamide NH group is more acidic than that of its oxygenated counterpart and consequently it is a stronger H-bonding donor. (ii) Its cis
Control over molecular motion using the cis–trans photoisomerization of the azo group
Beilstein J. Org. Chem. 2012, 8, 1071–1090, doi:10.3762/bjoc.8.119
- and S2←S0 excitations and cis–trans isomerization by exciting into the S1 or S2 state [21]. The sum of the quantum yields is different to unity, which indicates multiple pathways for isomerization. In stilbene, the isomerization occurs exclusively by rotation and the quantum yield equals unity [22
- does not affect cell survival, and similarly irradiation of incubated cells with LAMs not containing CPT, did not lead to cell death, thus confirming the biocompatibility of the LAMs with the cells. Molecular lift The individual molecular motion of azobenzene in the cis–trans isomerization process can
Diarylethene-modified nucleotides for switching optical properties in DNA
Beilstein J. Org. Chem. 2012, 8, 905–914, doi:10.3762/bjoc.8.103
- photoswitchable components in nucleic acids and are suitable for the control of a variety of different biological functions. The photoinduced cis–trans isomerization of azobenzene nucleosides can reversibly switch between the formation and dissociation of DNA duplexes [14][15][16][17], photoregulate DNA
- polymerase reaction [18], photocontrol DNA triplex formation [19], and drive photon-fueled DNA-based nanomachines [20][21]. Concerning the extent of structural change, the cis–trans isomerization of azobenzenes behaves much simpler than the ring opening of spiropyrans to merocyanines. In the latter case not
Photochemical and thermal intramolecular 1,3-dipolar cycloaddition reactions of new o-stilbene-methylene-3-sydnones and their synthesis
Beilstein J. Org. Chem. 2011, 7, 1663–1670, doi:10.3762/bjoc.7.196
- , where the sydnone moiety is part of a heterostilbene system, cis–trans isomerization was the main process, and no intramolecular cycloadducts were found owing to the unfavourable conformation of the formed intermediate in the trans configuration. The existence of the nitrile imine intermediate as a
- , namely, trans–cis and cis–trans isomerization of the stilbene moiety, and photolysis of the sydnone ring resulting in the formation of the nitrile imine intermediate. The nitrile imine species is, in intramolecular dipolar [3 + 2] cycloaddition, trapped by the cis- or trans-double bond of the stilbene
The arene–alkene photocycloaddition
Beilstein J. Org. Chem. 2011, 7, 525–542, doi:10.3762/bjoc.7.61
- that the meta photocycloaddition occurs from the singlet excited-state; they observed that 6-phenyl-2-hexene undergoes cis–trans isomerization upon sensitizing with acetone and benzophenone, whereas the photocycloaddition to the meta product could only be triggered via direct irradiation [23]. Mode
Exceptionally small supramolecular hydrogelators based on aromatic–aromatic interactions
Beilstein J. Org. Chem. 2011, 7, 167–172, doi:10.3762/bjoc.7.23
- properties. Notably, compound 6 can undergo cis/trans-isomerization upon UV irradiation. Keywords: aromatic–aromatic interaction; cinnamoyl; hydrogel; hydrogelator; supramolecular; Introduction Gels formed by three-dimensional, elastic networks to encapsulate a liquid [1], have many useful properties (e.g
- reversible cis/trans-isomerization provides an additional pathway for rearranging the supramolecular structures and achieving ordered supramolecular structures to produce well-dispersed nanofibers as the matrices of the hydrogels. The fact that compound 6 has the lowest molecular weight amongst the peptide
- and molecular structure, but also offers a small molecular building block for the development of enzyme based molecular self-assembly. Furthermore, cis/trans-isomerization offers a novel pathway for achieving well-dispersed nanofibers, which could be used in drug separation, drug release and other
Mechanistic aspects of the isomerization of Z-vinylic tellurides double bonds in the synthesis of potassium Z-vinyltrifluoroborate salts
Beilstein J. Org. Chem. 2008, 4, No. 9, doi:10.1186/1860-5397-4-9
- ), generates nBu•, which is responsible for the cis-trans isomerization. The butyl radical attack occurs at the boronic “ate” complex 4 (Scheme 1) [16], yielding the nBuBF3K salt as a final product. In order to verify the presence of radical species in the reaction mixture, we performed EPR spin trapping
Photosonochemical catalytic ring opening of α-epoxyketones
Beilstein J. Org. Chem. 2007, 3, No. 2, doi:10.1186/1860-5397-3-2
- trioxolane derivatives [32][33][34] or by dipolarophiles to form various tetrahydrofurans and dihydrofurans. [41] In the absence of appropriate dipolarophiles, cis/trans isomerization of the epoxide ring has been observed. [42] The cleavage of Cα-O or Cβ-O bonds has been confirmed either by rearrangement to
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