Coincident measurement of photo-ion circular dichroism and photo-electron circular dichroism

2020 ◽  
Vol 22 (24) ◽  
pp. 13707-13712
Author(s):  
Carl Stefan Lehmann ◽  
Karl-Michael Weitzel
Keyword(s):  
Circular Dichroism ◽  
Coincidence Experiment ◽  
First Time ◽  
Circular Dichroïsm

Photo-ion circular dichroism (PICD) and photo-electron circular dichroism (PECD) have been measured for the first time simultaneously in a coincidence experiment detecting the chirality of R- and S-Methyloxirane.

Chiral carbazole-based porphyrins showing absorption and circular dichroism in the near-infrared region

2020 ◽  
Vol 24 (01n03) ◽  
pp. 247-251
Author(s):  
Chihiro Maeda ◽  
Tadashi Ema
Keyword(s):  
Circular Dichroism ◽  
Near Infrared ◽  
Infrared Region ◽  
Nir Absorption ◽  
Near Infrared Region ◽  
Induced Aggregation ◽  
First Time ◽  
Circular Dichroïsm

Chiral carbazole-based porphyrins were synthesized for the first time via the incorporation of hydrobenzoin units at the thiophene moieties. They showed absorption and circular dichroism in the near-infrared (NIR) region. The NIR absorption was further red-shifted by solvent-induced aggregation.

scholarly journals Flowers in Australia: Phytochemical Studies on the Illawarra Flame Tree and Alstonville

2016 ◽  
Vol 69 (8) ◽  
pp. 925 ◽  
Author(s):  
Rudi Hendra ◽  
Paul A. Keller
Keyword(s):  
Circular Dichroism ◽  
Methyl Ester ◽  
Secondary Metabolites ◽  
Absolute Configuration ◽  
Circular Dichroism Spectroscopy ◽  
Purple Colour ◽  
Traditional Uses ◽  
Phytochemical Studies ◽  
First Time ◽  
Circular Dichroïsm

The first reported phytochemical studies on two species of flowers in Australia enabled the identification of six secondary metabolites from Illawarra flame tree flower (Brachychiton acerifolius) and seven secondary metabolites from the flowers of the Alstonville (Tibouchina lepidota). Pelargonidin 3-(6-coumarylglucoside)-5-(6-acetylglucoside) was found to be responsible for the red colour of B. acerifolius, whereas malvidin 3-(coumarylglucoside)-5-(acetylxyloside) was responsible for the purple colour of (T. lepidota) flowers. (2S)-4,5-Dihydroxyflavanone 7-O-β-d-glucuronide methyl ester was isolated for the first time from B. acerifolius, and its absolute configuration was determined by circular dichroism spectroscopy. Some of the traditional uses of B. acerifolius could also be correlated with the known activity of the isolated metabolites.

Absorption and magnetic circular dichroism spectra of metal-free phthalocyanine in ultraviolet-transparent solvents

1979 ◽  
Vol 57 (9) ◽  
pp. 1111-1113 ◽  
Author(s):  
Katherine A. Martin ◽  
Martin J. Stillman
Keyword(s):  
Circular Dichroism ◽  
Magnetic Circular Dichroism ◽  
Electron System ◽  
Spectral Envelope ◽  
Central Metal ◽  
Circular Dichroism Spectra ◽  
Metal Free ◽  
First Time ◽  
Circular Dichroïsm ◽  
Magnetic Circular Dichroism Spectra

Absorption and magnetic circular dichroism spectra of metal-free phthalocyanine (H2Pc) have been recorded over the range 270–800 nm. The use of solvents transparent in the 270–400 nm region allows the observation for the first time of the B band spectral envelope of H2Pc in solution. The mcd spectrum clearly indicates that the complex (NH4)2Pc is formed when ammonia is bubbled through a solution of H2Pc in dimethyl sulphoxide. The multi-transition nature of the B band region is identified as a property of the phthalocyanine π electron system rather than arising from charge transfer between the ring and a central metal cation.

Circularly polarized luminescence in chiral silver nanoclusters

2017 ◽  
Vol 53 (7) ◽  
pp. 1269-1272 ◽  
Author(s):  
Jatish Kumar ◽  
Tsuyoshi Kawai ◽  
Takuya Nakashima
Keyword(s):  
Circular Dichroism ◽  
Mirror Image ◽  
Silver Nanoclusters ◽  
Dihydrolipoic Acid ◽  
Circularly Polarized ◽  
Circularly Polarized Luminescence ◽  
Polarized Luminescence ◽  
First Time ◽  
Circular Dichroïsm

Sets of mirror image circular dichroism (CD) and circularly polarized luminescence (CPL) spectra are for the first time demonstrated using enantiomeric dihydrolipoic acid (DHLA)-capped silver nanoclusters.

Two Rare Hydroazulene-type Sesquiterpenes from the Roots of Aristolochia yunnanensis

2014 ◽  
Vol 69 (6) ◽  
pp. 742-746 ◽  
Author(s):  
Zhuo Du ◽  
Feng-Ni Wen ◽  
Ji-Ping Zhang ◽  
Jian-Feng Wua ◽  
Fang Liu ◽  
...  
Keyword(s):  
Circular Dichroism ◽  
Cell Lines ◽  
Spectroscopic Data ◽  
Cytotoxic Activities ◽  
Moderate Activity ◽  
Electronic Circular Dichroism ◽  
The Third ◽  
The Absolute ◽  
First Time ◽  
Circular Dichroïsm

Two new sesquiterpenes, named aristoyunnolin I (1) and J (2), together with eight known compounds (3 - 10) were isolated from the roots of Aristolochia yunnanensis. Compounds 1 and 2 feature a rare hydroazulene-type sesquiterpene skeleton and represent the third and fourth examples of this kind found in nature. The structures were determined from spectroscopic data, and the absolute configurations of 1 - 3 were assigned by comparing experimental with simulated electronic circular dichroism (ECD) spectra. Compounds 1, 2, 6 - 10 were isolated from this plant for the first time. The cytotoxic activities of 1 - 10 were evaluated against P-388 and A-549 cell lines. Only compounds 4 and 5 showed moderate activity with IC50 values ranging from 12.0 to 18.2 μM.

scholarly journals Isolation and Absolute Configurations of Diversiform C17, C21 and C25 Terpenoids from the Marine Sponge Cacospongia sp.

Marine Drugs ◽  
2018 ◽  
Vol 17 (1) ◽  
pp. 14 ◽  
Author(s):  
Xingwang Zhang ◽  
Ping-Lin Li ◽  
Guo-Fei Qin ◽  
Shengying Li ◽  
Nicole de Voogd ◽  
...  
Keyword(s):  
Circular Dichroism ◽  
Cell Lines ◽  
Optical Rotation ◽  
Human Tumor ◽  
Chiral Hplc ◽  
Pure Compounds ◽  
New Compounds ◽  
First Time ◽  
Optically Pure ◽  
Circular Dichroïsm

Chemical investigation of MeOH extract of a South China Sea sponge Cacospongia sp. yielded 15 terpenoids belonging to three different skeleton-types, including the unusual C17 γ-lactone norditerpenoids (1–3), the rare C21 pyridine meroterpenoid (7), and the notable C25 manoalide-type sesterterpenoids (4–6, 8–10). Compounds 1–5 were initially obtained as enantiomers, and were further separated to be optically pure compounds (1a, 1b, 2a, 2b, 3a-r, 3b-r, 4a, 4b, 5a and 5b) by chiral HPLC, with a LiAlH4 reduction aid for 3. Compounds 3a/3b (a pair of inseparable enantiomers), 4a, 5a, 6, and 7 were identified as new compounds, while 1a/1b and 2a/2b were obtained from a natural source and were determined for their absolute configurations for the first time. This is also the first time to encounter enantiomers of the well-known manoalide-type sesterterpenoids from nature. The structures with absolute configurations of the new compounds were unambiguously determined by comprehensive methods including HR-ESI-MS and NMR data analysis, optical rotation comparison, experimental and calculated electronic circular dichroism (ECD), and Mo2(OAc)4 induced circular dichroism (ICD) methods. The cytotoxicity of the isolates against selected human tumor cell lines was evaluated, however, the tested compounds showed no activity against selected cell lines.

Photophysical properties of quinoxaline-fused [7]carbohelicene derivatives

RSC Advances ◽  
2015 ◽  
Vol 5 (89) ◽  
pp. 72907-72915 ◽  
Author(s):  
Chunyu Liu ◽  
Yanling Si ◽  
Xiumei Pan ◽  
Guochun Yang
Keyword(s):  
Circular Dichroism ◽  
Nonlinear Optics ◽  
Charge Transport ◽  
Transport Properties ◽  
Photophysical Properties ◽  
Electronic Circular Dichroism ◽  
First Time ◽  
Circular Dichroïsm

The electronic circular dichroism, UV-Vis absorption, nonlinear optics, and charge transport properties of novel quinoxaline-fused 7-carbohelicene derivatives have been investigated for the first time.

Substituent effect in theoretical VCD spectra

RSC Advances ◽  
2014 ◽  
Vol 4 (51) ◽  
pp. 27062-27066 ◽  
Author(s):  
Piotr F. J. Lipiński ◽  
Jan Cz. Dobrowolski
Keyword(s):  
Circular Dichroism ◽  
Substituent Effect ◽  
Vibrational Circular Dichroism ◽  
Correlational Study ◽  
First Time ◽  
Circular Dichroïsm

A correlational study shows for the first time a quantitative substituent effect on Vibrational Circular Dichroism intensity.

scholarly journals Fluorescence Detected Circular Dichroism (FDCD) for Supramolecular Host-Guest Complexes

2021 ◽  
Author(s):  
Amrutha Prabodh ◽  
Yichuan Wang ◽  
Stephan Sinn ◽  
Paolo Albertini ◽  
Christian Spies ◽  
...  
Keyword(s):  
Circular Dichroism ◽  
Host Protein ◽  
Electronic Circular Dichroism ◽  
First Time ◽  
Circular Dichroïsm

Fluorescence-detected circular dichroism (FDCD) spectroscopy is applied for the first time to supramolecular host-guest and host-protein systems and compared to the more known electronic circular dichroism (ECD). We find that...

Cinerin C: a macrophyllin-type bicyclo[3.2.1]octane neolignan fromPleurothyrium cinereum(Lauraceae)

2012 ◽  
Vol 68 (8) ◽  
pp. o320-o322
Author(s):  
Ericsson D. Coy-Barrera ◽  
Luis E. Cuca-Suárez ◽  
Michael Sefkow ◽  
Uwe Schilde
Keyword(s):  
Hydrogen Bond ◽  
Circular Dichroism ◽  
Single Crystal ◽  
Absolute Configuration ◽  
Ethanol Extract ◽  
X Ray ◽  
Naturally Occurring ◽  
First Time ◽  
Circular Dichroïsm

The structure of naturally-occurring cinerin C [systematic name: (7S,8R,3′R,4′S,5′R)-Δ8′-4′-hydroxy-5,5′,3′-trimethoxy-3,4-methylenedioxy-2′,3′,4′,5′-tetrahydro-2′-oxo-7.3′,8.5′-neolignan], isolated from the ethanol extract of leaves ofPleurothyrium cinereum(Lauraceae), has previously been established by NMR and HRMS spectroscopy, and its absolute configuration established by circular dichroism measurements. For the first time, its crystal strucure has now been established by single-crystal X-ray analysis, as the monohydrate, C22H26O7·H2O. The bicyclooctane moiety comprises fused cyclopentane and cyclohexenone rings which are almost coplanar. An intermolecular O—H...O hydrogen bond links the 4′-OH and 5′-OCH3groups along thecaxis.

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