ChemInform Abstract: A New Class of Room Temperature Luminescent Organometallic Complexes: Luminescence and Photophysical Properties of Permethylscandocene Chloride in Fluid Solution.

ChemInform ◽  
1990 ◽  
Vol 21 (11) ◽  
Author(s):  
B. W. PFENNIG ◽  
M. E. THOMPSON ◽  
A. B. BOCARSLY
2009 ◽  
Vol 87 (1) ◽  
pp. 254-263 ◽  
Author(s):  
Francesco Nastasi ◽  
Frédérique Loiseau ◽  
Sebastiano Campagna ◽  
Elaine A Medlycott ◽  
Marie-Pierre Santoni ◽  
...  

A family made of four bis(pyridyl)triazine ligands with appended aryl rings, including three fused aromatic rings, have been synthesized, and their corresponding homoleptic Ru(II) and Zn(II) complexes have been prepared and characterized by several means. The free ligands 2,4-di(2-pyridyl)-6-phenyl-1,3,5-triazine (L1); 2,4-di(2-pyridyl)-6-(1-naphthyl)-1,3,5-triazine (L2); 2,4-di(2-pyridyl)-6-(9-phenanthryl)-1,3,5-triazine (L3); and 2,4-di(2-pyridyl)-6-(1-pyrenyl)-1,3,5-triazine (L4) were formed in triazine ring-forming reactions from the reactions of the cyano-functionalized aromatic rings with LiNMe2 followed by the addition of 2 equiv. of 2-cyanopyridine. The metal complexes examined in this study are the homoleptic Ru(II) complexes Ru(L1)22+ (2a), Ru(L2)22+ (2b), Ru(L3)22+ (2c), and Ru(L4)22+ (2d) and Zn(II) complexes Zn(L1)22+ (3a), Zn(L2)22+ (3b), Zn(L3)22+ (3c), and Zn(L4)22+ (3d). Also, crystallographic data for the free ligands and Zn(II) and Ru(II) complexes have been obtained in some cases. The redox behaviour and absorption spectra of all the species have been investigated, together with the luminescence properties of the free ligands at room temperature in fluid solution and of the Ru(II) complexes both at room temperature in fluid solution and at 77 K in rigid matrix. The redox data indicate that the free ligands are reduced twice at relatively mild potentials (< –2.30 V vs. SCE), with the first reduction almost independent of the nature of the substituted aryl group. The UV absorption spectra of all the compounds are dominated by intense spin-allowed π–π* transitions mainly centered on the bis(pyridyl)triazine moiety; however, in L2–L4, moderately intense intraligand charge-transfer (ILCT) bands are also present. Such bands are red-shifted in the Zn(II) compounds, while they are obscured in the Ru(II) species by the more intense spin-allowed metal-to-ligand charge-transfer (MLCT) bands. The free ligands exhibit interesting emission properties, ranging from fluorescence from π–π* states to excimeric (in L4) and ILCT (in L2 and L3) emission. In the Ru(II) complexes, strong emission is found at 77 K from triplet MLCT states. For 2c and 2d, the emissive MLCT states are mixed with low-lying triplet ligand-centered states.Key words: triazine ligands, ruthenium complexes, zinc complexes, ILCT emission.


2021 ◽  
Vol 23 (10) ◽  
pp. 6182-6189
Author(s):  
Dariusz M. Niedzwiedzki

Photophysical properties of N719 and Z907, benchmark Ru-dyes used as sensitizers in dye-sensitized solar cells, were studied by static and time-resolved optical spectroscopy at room temperature and 160 K.


2017 ◽  
Vol 38 (1) ◽  
pp. 97-110 ◽  
Author(s):  
Artur Kubiczek ◽  
Władysław Kamiński

AbstractRoom-temperature ionic liquids (RTILs) are a moderately new class of liquid substances that are characterized by a great variety of possible anion-cation combinations giving each of them different properties. For this reason, they have been termed as designer solvents and, as such, they are particularly promising for liquid-liquid extraction, which has been quite intensely studied over the last decade. This paper concentrates on the recent liquid-liquid extraction studies involving ionic liquids, yet focusing strictly on the separation of n-butanol from model aqueous solutions. Such research is undertaken mainly with the intention of facilitating biological butanol production, which is usually carried out through the ABE fermentation process. So far, various sorts of RTILs have been tested for this purpose while mostly ternary liquid-liquid systems have been investigated. The industrial design of liquid-liquid extraction requires prior knowledge of the state of thermodynamic equilibrium and its relation to the process parameters. Such knowledge can be obtained by performing a series of extraction experiments and employing a certain mathematical model to approximate the equilibrium. There are at least a few models available but this paper concentrates primarily on the NRTL equation, which has proven to be one of the most accurate tools for correlating experimental equilibrium data. Thus, all the presented studies have been selected based on the accepted modeling method. The reader is also shown how the NRTL equation can be used to model liquid-liquid systems containing more than three components as it has been the authors’ recent area of expertise.


2013 ◽  
Vol 117 (7) ◽  
pp. 3683-3683
Author(s):  
Parbatee Samaroo Jagassar ◽  
Anthony Perri ◽  
Guillermo Ibarrola ◽  
Harry D. Gafney

2015 ◽  
Vol 51 (43) ◽  
pp. 8939-8941 ◽  
Author(s):  
Sandra Medina ◽  
Alexander S. Henderson ◽  
John F. Bower ◽  
M. Carmen Galan

The use of (salen)Co catalysts as a new class of bench-stable stereoselective glycosylation promoters of trichloroacetimidate glycosyl donors at room temperature is described.


Nanoscale ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 242-252
Author(s):  
Goonay Yousefalizadeh ◽  
Shideh Ahmadi ◽  
Nicholas J. Mosey ◽  
Kevin G. Stamplecoskie

Noble metal clusters have unique photophysical properties, especially as a new class of materials for multiphoton biomedical imaging.


2019 ◽  
Vol 43 (3-4) ◽  
pp. 101-106
Author(s):  
Nieves Canudas ◽  
Manuel Moreno ◽  
Sara Pekerar ◽  
Carlos Gámez ◽  
Estefania Sucre ◽  
...  

Three new Z-chalcone derivatives were synthesized under stereoselective conditions by condensation between an aldehyde derivative (prepared from aloe-emodin) and an acetophenone, using potassium hydroxide in dimethyl sulfoxide/H2O at room temperature. The Z configuration of the chalcone derivatives was established by nuclear magnetic resonance (NMR) studies. Photophysical properties related to the UV-Vis absorption/emission spectra and molar extinction coefficients (ε) in different solvents were determined.


2020 ◽  
Vol 8 (40) ◽  
pp. 14037-14048
Author(s):  
Pavan Kumar-Ventrapati ◽  
Shantanu Misra ◽  
Gaëlle Delaizir ◽  
Anne Dauscher ◽  
Bertrand Lenoir ◽  
...  

The n-type chalcogenide Bi8Se7 is the parent compound of a new class of highly-efficient thermoelectric materials for near-room-temperature thermoelectric applications.


1991 ◽  
Vol 255 (2) ◽  
pp. 351-357 ◽  
Author(s):  
A.Muñoz de la Peña ◽  
I. Durán-Merás ◽  
F. Salinas ◽  
I.M. Warner ◽  
T.T. Ndou

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