Sterically demanding methoxy and methyl groups in ruthenium complexes lead to enhanced quantum yields for blue light triggered photodissociation

2018 ◽  
Vol 47 (44) ◽  
pp. 15685-15693 ◽  
Author(s):  
Fengrui Qu ◽  
Kristina Martinez ◽  
Ashley M. Arcidiacono ◽  
Seungjo Park ◽  
Matthias Zeller ◽  
...  
Keyword(s):  
Blue Light ◽  
Ruthenium Complexes ◽  
Donor Ligands ◽  
Quantum Yields ◽  
Methyl Groups ◽  
Sterically Demanding ◽  
The Impact

Ruthenium complexes exhibit enhanced photodissociation quantum yields due to bulky, weak donor ligands, illustrating the impact of electronics and sterics.

Synthesis and Biological Evaluations of Organoruthenium Scaffolds: A Comprehensive Update

2018 ◽  
Vol 15 (2) ◽  
pp. 179-207
Author(s):  
Ashaparna Mondal ◽  
Priyankar Paira
Keyword(s):  
Singlet Oxygen ◽  
Anticancer Agents ◽  
Ruthenium Complexes ◽  
Chemotherapeutic Agents ◽  
Quantum Yields ◽  
Ros Generation ◽  
Standard Drug ◽  
Cellular Environment ◽  
Theranostic Agents

Background: Currently ruthenium complexes are immerging as effective anticancer agents due to their less toxicity, better antiproliferative and antimetastatic activity, better stability in cellular environment and most importantly variable oxidation and co-ordination states of ruthenium allows binding this molecule with a variety of ligands. So in past few years researchers have shifted their interest towards organoruthenium complexes having good fluorescent profile that may be applicable for cancer theranostics. Nowadays, photodynamic therapy has become more acceptable because of its easy and effective approach towards killing cancer cells. Objective: Objective of this review article is to shed light on synthesis, characterization, stability and fluorescence studies of various ruthenium [Ru(II) and Ru(III)] complexes and different bioactivity studies conducted with the synthesized compounds to test their candidacy as potent chemotherapeutic agents. Methods: Various heterocyclic ligands containing N,O and S as heteroatom mainly were prepared and subjected to complexation with ruthenium-p-cymene moiety. In most cases [Ru(η6-p-cymene)(µ-Cl)Cl]2 was used as ruthenium precursor and the reactions were conducted in various alcohol medium such as methanol, ethanol or propanol. The synthesized complexes were characterized by 1H NMR and 13C NMR spectroscopy, GC-MS, ESI-MS, elemental analysis and single crystal X-ray crystallography methods. Fluorescence study and stability study were conducted accordingly using water, PBS buffer or DMSO. Stable compounds were considered for cell viability studies. To study the efficacy of the compounds in ROS generation as photosensitizers, in few cases, singlet oxygen quantum yields in presence of light were calculated. Suitable compounds were selected for in vitro & in vivo antiproliferative, anti-invasive activity studies. Result: Many newly synthesized compounds were found to have less IC50 compared to a standard drug cysplatin. Those compounds were also stable preferably in physiological conditions. Good fluorescence profile and ROS generation ability were observed for few compounds. Conclusion: Numerous ruthenium complexes were developed which can be used as cancer theranostic agents. Few molecules were synthesized as photosensitizers which were supposed to generate reactive singlet oxygen species in targeted cellular environment in presence of a particular type of light and thereby ceasing cancer cell growth.

scholarly journals The Impact of Blue Light Cystoscopy with Hexaminolevulinate (HAL) on Progression of Bladder Cancer – A New Analysis

2016 ◽  
Vol 2 (2) ◽  
pp. 273-278 ◽  
Author(s):  
Ashish M. Kamat ◽  
Michael Cookson ◽  
J. Alfred Witjes ◽  
Arnulf Stenzl ◽  
H. Barton Grossman
Keyword(s):  
Bladder Cancer ◽  
Blue Light ◽  
The Impact

scholarly journals Modeling of photolysis rates over Europe: impact on chemical gaseous species and aerosols

2011 ◽  
Vol 11 (4) ◽  
pp. 1711-1727 ◽  
Author(s):  
E. Real ◽  
K. Sartelet
Keyword(s):  
Air Quality ◽  
Transport Model ◽  
Quantum Yields ◽  
Strong Impact ◽  
Peak Reduction ◽  
Gaseous Species ◽  
Clear Sky ◽  
Photolysis Rate ◽  
Photolysis Rates ◽  
The Impact

Abstract. This paper evaluates the impact of photolysis rate calculation on simulated European air composition and air quality. In particular, the impact of the cloud parametrisation and the impact of aerosols on photolysis rates are analysed. Photolysis rates are simulated using the Fast-JX photolysis scheme and gas and aerosol concentrations over Europe are simulated with the regional chemistry-transport model Polair3D of the Polyphemus platform. The photolysis scheme is first used to update the clear-sky tabulation of photolysis rates used in the previous Polair3D version. Important differences in photolysis rates are simulated, mainly due to updated cross-sections and quantum yields in the Fast-JX scheme. In the previous Polair3D version, clouds were taken into account by multiplying the clear-sky photolysis rates by a correction factor. In the new version, clouds are taken into account more accurately by simulating them directly in the photolysis scheme. Differences in photolysis rates inside clouds can be large but outside clouds, and especially at the ground, differences are small. To take into account the impact of aerosols on photolysis rates, Polair3D and Fast-JX are coupled. Photolysis rates are updated every hour. Large impact on photolysis rates is observed at the ground, decreasing with altitude. The aerosol specie that impact the most photolysis rates is dust especially in south Europe. Strong impact is also observed over anthropogenic emission regions (Paris, The Po and the Ruhr Valley) where mainly nitrate and sulphate reduce the incoming radiation. Differences in photolysis rates lead to changes in gas concentrations, with the largest impact simulated on OH and NO concentrations. At the ground, monthly mean concentrations of both species are reduced over Europe by around 10 to 14% and their tropospheric burden by around 10%. The decrease in OH leads to an increase of the life-time of several species such as VOC. NO2 concentrations are not strongly impacted and O3 concentrations are mostly reduced at the ground (−3%). O3 peaks are systematically decreased because of the NO2 photolysis rate coefficient decrease. Not only gas are impacted but also secondary aerosols, due to changes in gas precursors concentrations. However changes in aerosol species concentrations often compensate each other resulting in a low impact on PM10 and PM2.5 concentrations (lower than 2%). The changes in gas concentrations at the ground induced by the modification of photolysis rates (by aerosols and clouds) are compared to changes induced by 29 different model parametrisations in Roustan et al. (2010). Among the 31 model parametrisations, "including aerosols on photolysis rates calculation" has the strongest impact on OH concentrations and on O3 bias in July. In terms of air quality, ground concentrations (NO2, O3, PM10) are compared with measurements. Changes arising from cloud parametrisation are small. Simulation performances are often slightly better when including aerosol in photolysis rates calculation. The systematic O3 peak reduction leads to large differences in the exceedances of the European O3 standard as calculated by the model, in better agreement with measurements. The number of exceedances of the information and the alert threshold is divided by 2 when the aerosol impact on photochemistry is simulated. This shows the importance of taking into account aerosols impact on photolysis rates in air quality studies.

Studies of Degradation in Nichia AlGaN/InGaN/GaN Blue Light Emitting Diodes Under Close to Normal Operating Conditions

1996 ◽  
Vol 421 ◽  
Author(s):  
M. Osiński ◽  
D. L. Barton ◽  
C. J. Helms ◽  
P. Perlin ◽  
N. H. Berg ◽  
...  
Keyword(s):  
Blue Light ◽  
Light Emitting Diodes ◽  
Defect Density ◽  
Degradation Process ◽  
Operating Conditions ◽  
Similar Amount ◽  
Life Testing ◽  
Light Emitting ◽  
High Pulsed Current ◽  
The Impact

AbstractThe reliability of devices fabricated in GaN and related alloys, especially under high current densities as would be found in lasers, has yet to be fully characterized. Our previous work [1] investigated the degradation of GaN-based blue light emitting diodes (LEDs) under high pulsed current stress. This work indicated a possible correlation between the high crystal defect density and failures caused by metal migration along these defect tubes. To assess the impact of this data on devices under more normal conditions, several LEDs from both older and more recent production lots were placed in a controlled temperature and current environment for several thousand hours. The test started with a constant 20 mA current for the first 1000 hours and continued for another 1650 hours at various currents up to 70 mA, all at a temperature of 23 °C. During this test, one of the older generation LED's output degraded by more than 50%. Subsequent failure analysis showed that this was caused by a crack which isolated part of the active region from the p-contact. The remaining LEDs were returned to life testing where the temperature was subsequently increased by 5 °C after each 500 hours of testing. The output from one of the newer LEDs dreiven at 70 mA degraded to 55% of its original value after 3600 hours and a second newer LED degraded by a similar amount after 4400 hours. The first failure, LED #16, did not exhibit a significant change in its I-V characteristics indicating that a change in the package transparency was a likely cause for the observed degradation. The second failure, LED #17, did show a noticeable change in its I-V characteristics. This device was subsequently returned to life testing where the degradation process will be monitored for further changes.

Involvement of various anions in tuning the structure of silver(I) coordination polymers based on the S- donor ligands: Syntheses, crystal structure and uptake properties

CrystEngComm ◽  
2021 ◽  
Author(s):  
susan soleymani babadi ◽  
Azizollah Beheshti ◽  
Maryam bahrani ◽  
Behrang Salahshour nia ◽  
Hamid Reza Zafarian ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Coordination Polymers ◽  
Donor Ligands ◽  
Counter Ions ◽  
Coordination Ability ◽  
The Impact

An investigation of the impact of shape, size and coordination ability of the counter ions was carried out on a five silver(I)- 1, 2- bis (1-methylthioimidazolyl) ethane coordination polymers namely,...

Neutral η6-arene ruthenium complexes with monodentate P-donor ligands

2012 ◽  
Vol 363-364 ◽  
pp. 49-57 ◽  
Author(s):  
Arnald Grabulosa ◽  
Alberto Mannu ◽  
Elisabetta Alberico ◽  
Stefania Denurra ◽  
Serafino Gladiali ◽  
...  
Keyword(s):  
Ruthenium Complexes ◽  
Donor Ligands

scholarly journals The impact of blue light on leaf mesophyll conductance

2009 ◽  
Vol 60 (8) ◽  
pp. 2283-2290 ◽  
Author(s):  
Francesco Loreto ◽  
Tsonko Tsonev ◽  
Mauro Centritto
Keyword(s):  
Blue Light ◽  
Mesophyll Conductance ◽  
Leaf Mesophyll ◽  
The Impact

Ruthenium complexes containing group 5b donor ligands

1978 ◽  
Vol 161 (3) ◽  
pp. 391-406 ◽  
Author(s):  
P.W. Armit ◽  
W.J. Sime ◽  
T.A. Stephenson ◽  
L. Scott
Keyword(s):  
Ruthenium Complexes ◽  
Donor Ligands

scholarly journals Blue light attracts nocturnally migrating birds

The Condor ◽  
2020 ◽  
Vol 122 (2) ◽  
Author(s):  
Xuebing Zhao ◽  
Min Zhang ◽  
Xianli Che ◽  
Fasheng Zou
Keyword(s):  
Blue Light ◽  
Field Experiments ◽  
Red Light ◽  
Light Pollution ◽  
Artificial Light ◽  
Light Sources ◽  
Rapid Urbanization ◽  
Phototactic Response ◽  
Migrating Birds ◽  
The Impact

Abstract Light pollution is increasing and artificial light sources have great impacts on animals. For migrating birds, collisions caused by artificial light pollution are a significant source of mortality. Laboratory studies have demonstrated that birds have different visual sensitivities to different colors of light, but few field experiments have compared birds’ responses to light of different wavelengths. We used 3 monochromatic lights (red, green, and blue) and polychromatic yellow light to study the impact of wavelength on phototaxis at 2 gathering sites of nocturnally migrating birds in Southwest China. For both sites, short-wavelength blue light caused the strongest phototactic response. In contrast, birds were rarely attracted to long-wavelength red light. The attractive effect of blue light was greatest during nights with fog and headwinds. As rapid urbanization and industrialization cause an increase in artificial light, we suggest that switching to longer wavelength lights is a convenient and economically effective way to reduce bird collisions.

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