scholarly journals UV-Light-Induced Vibrational Coherences: The Key to Understand Kasha Rule Violation in trans-Azobenzene

2018 ◽  
Vol 9 (7) ◽  
pp. 1534-1541 ◽  
Author(s):  
Artur Nenov ◽  
Rocio Borrego-Varillas ◽  
Aurelio Oriana ◽  
Lucia Ganzer ◽  
Francesco Segatta ◽  
...  
Keyword(s):  
Uv Light ◽  
Rule Violation ◽  
In Trans ◽  
Trans Azobenzene

Resonant Raman excitation profile of the 220 cm−1 mode in trans-azobenzene

1992 ◽  
Vol 23 (3) ◽  
pp. 155-160 ◽  
Author(s):  
A. Biancalana ◽  
E. Campani ◽  
G. Gorini ◽  
G. Masetti ◽  
M. Quaglia
Keyword(s):  
Excitation Profile ◽  
In Trans ◽  
Resonant Raman ◽  
Trans Azobenzene

S2 → S0 fluorescence in trans-azobenzene

1979 ◽  
Vol 68 (2-3) ◽  
pp. 267-271 ◽  
Author(s):  
C.G. Morgante ◽  
W.S. Struve
Keyword(s):  
In Trans ◽  
Trans Azobenzene

Photoregulative Phase Change Biomaterials Showing Thermodynamic and Mechanical Stabilities

Nanoscale ◽  
2022 ◽  
Author(s):  
Lei Zhang ◽  
Jingjing Gu ◽  
Xiliang Luo ◽  
Zhenyu Tang ◽  
Cong-Xia Xie ◽  
...  
Keyword(s):  
Physical Properties ◽  
Phase Change ◽  
Uv Light ◽  
Photochromic Molecules ◽  
Trans Azobenzene

Azobenzenes are great photochromic molecules for switching the physical properties of various materials via trans-cis isomerization. However, the UV light resulted cis-azobenzene is metastable and thermodynamically gets back to trans-azobenzene...

Vibrational coupling in trans-azobenzene and its isotopomers

1997 ◽  
Vol 408-409 ◽  
pp. 399-403 ◽  
Author(s):  
Zlatko Meić ◽  
Goran Baranovi^'c ◽  
Vilko Smrečki ◽  
Predrag Novak ◽  
Gábor Keresztury ◽  
...  
Keyword(s):  
Vibrational Coupling ◽  
In Trans ◽  
Trans Azobenzene

Nitrogen-15 shielding in trans-azobenzene

1989 ◽  
Vol 67 (7) ◽  
pp. 1219-1224 ◽  
Author(s):  
Roderick E. Wasylishen ◽  
William P. Power ◽  
Glenn H. Penner ◽  
Ronald D. Curtis
Keyword(s):  
Solid State Nmr ◽  
Experimental Error ◽  
Theoretical Calculations ◽  
Relative Orientation ◽  
General Direction ◽  
Molecular Plane ◽  
Shielding Constants ◽  
In Trans ◽  
Shielding Tensor ◽  
Trans Azobenzene

The principal values of the nitrogen nuclear magnetic resonance shielding tensor for trans-azobenzene have been measured and compared with theoretical values recently reported for trans-diazene. The shielding anisotropy for the two crystallographically nonequivalent molecules in trans-azobenzene is 925 and 880 ppm respectively, about 40% smaller than the value calculated for trans-diazene. Interestingly, the isotropic shielding constants for the two nonequivalent molecules are the same with in experimental error. The most shielded component of the 15N shielding tensor, σ33, is approximately perpendicular to the molecular plane, as it is in other planar π-systems; σ11, the least shielded component, is directed in the same general direction as the N—Cipso bond. The theoretical calculations overestimate the paramagnetic contribution to σ11. The magnitude and relative orientation of the nitrogen shielding tensor in trans-azobenzene are also compared with the corresponding phosphorus values in a diphosphene. Keywords: 15N chemical shielding anisotropy, solid state NMR, trans-azobenzene.

scholarly journals UV-light induced vibrational coherences explain Kasha rule violation in frans-azobenzene

2019 ◽  
Vol 205 ◽  
pp. 09016
Author(s):  
Artur Nenov ◽  
Rocio Borrego-Varillas ◽  
Aurelio Oriana ◽  
Lucia Ganzer ◽  
Francesco Segatta ◽  
...  
Keyword(s):  
Absorption Spectroscopy ◽  
Ground State ◽  
Transient Absorption ◽  
Uv Light ◽  
Decay Channel ◽  
Transient Absorption Spectroscopy ◽  
Rule Violation

Sub-20-fs transient absorption spectroscopy and simulations show that CNN-bendings dominate the sub-ps dynamics of ππ*-excited trans-azobenzene, thereby driving the system to the ground state through a non-productive decay channel in violation of the Kasha rule.

scholarly journals Invitro Photo-Controlled Drug Release System Based on Amphiphilic Linear-Dendritic Diblock Copolymers; Self-Assembly Behavior and Application as Nanocarrier

2011 ◽  
Vol 14 (2) ◽  
pp. 162 ◽  
Author(s):  
Hassan Namazi ◽  
Saeed Jafarirad
Keyword(s):  
Diblock Copolymers ◽  
Uv Light ◽  
Drug Carrier ◽  
In Vitro Release ◽  
Simple Type ◽  
Release Behavior ◽  
Trans Form ◽  
Ability To Act ◽  
Micellar Aggregates ◽  
In Trans

Purpose. A simple type of photoresponsive amphiphilic linear-dendritic diblock copolymer has been synthesized and investigated for its ability to act as a drug carrier. These structures contain hydrophilic polyethylene oxide monomethyl ether (PEOM) as hydrophilic block and carbosiloxane dendritic branches as hydrophobic block grafted by two and six Magneson II as azo chromophore, PEOM-Azo, 2 and PEOM-Azo, 6 respectively. Self-assembling of the amphiphilic macromolecules of PEOM-Azo, 2 and PEOM-Azo, 6, briefly were represented as PEOM-Azo [2, 6], leads to the formation of their micellar aggregates in aqueous media. Method. Their micellar properties such as critical micelle concentration (CMC), aggregation number and thereby total numbers of azo-groups in each micellar aggregates were determined. Also, they were characterized by TEM, SEM and DLS. Results. The unloaded aggregates examined under UV light (366 nm), which were observed to be smaller than 300 nm. The release patterns of the encapsulated drug molecule from these aggregates were investigated as regulated by the PEOM-Azo [2, 6] systems in trans and cis forms. Conclusion. A comparison of the release behavior of the loaded PEOM-Azo [2, 6] systems indicated that the release rate of the encapsulated active molecules from the carriers was slower when the azo moieties were in trans form as compared to that the azo in the cis form. The in vitro release behavior of drug from these polymeric systems represents potential of the carriers for controlled drug delivery. This article is open to POST-PUBLICATION REVIEW. Registered readers (see “For Readers”) may comment by clicking on ABSTRACT on the issue’s contents page.

Cooperating Dinitrogen and Phenyl Rotations in trans-Azobenzene Photoisomerization

2012 ◽  
Vol 8 (7) ◽  
pp. 2352-2358 ◽  
Author(s):  
José A. Gámez ◽  
Oliver Weingart ◽  
Axel Koslowski ◽  
Walter Thiel
Keyword(s):  
In Trans ◽  
Trans Azobenzene

Electron microscopy of keratinocytes cultured on a collagen substrate used as an allograft for the treatment of chronic wounds

1992 ◽  
Vol 50 (2) ◽  
pp. 1104-1105
Author(s):  
Debby A. Jennings ◽  
Michael J. Morykwas ◽  
Louis C. Argenta
Keyword(s):  
Electron Microscopy ◽  
Cell Suspension ◽  
Single Cell ◽  
Chronic Wounds ◽  
Mechanical Stability ◽  
Uv Light ◽  
Type I ◽  
Single Cell Suspension ◽  
Collagen Substrate ◽  
Dermal Collagen

Grafts of cultured allogenic or autogenic keratlnocytes have proven to be an effective treatment of chronic wounds and burns. This study utilized a collagen substrate for keratinocyte and fibroblast attachment. The substrate provided mechanical stability and augmented graft manipulation onto the wound bed. Graft integrity was confirmed by light and transmission electron microscopy.Bovine Type I dermal collagen sheets (100 μm thick) were crosslinked with 254 nm UV light (13.5 Joules/cm2) to improve mechanical properties and reduce degradation. A single cell suspension of third passage neonatal foreskin fibroblasts were plated onto the collagen. Five days later, a single cell suspension of first passage neonatal foreskin keratinocytes were plated on the opposite side of the collagen. The grafts were cultured for one month.The grafts were fixed in phosphate buffered 4% formaldehyde/1% glutaraldehyde for 24 hours. Graft pieces were then washed in 0.13 M phosphate buffer, post-fixed in 1% osmium tetroxide, dehydrated, and embedded in Polybed 812.

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