C2-Selective Silylation of Pyridines by a Rhodium–Aluminum Complex

2021 ◽  
Author(s):  
Naofumi Hara ◽  
Nao Uemura ◽  
Yoshiaki Nakao
Keyword(s):  

We have developed a C2-selective mono-silylation of a variety of pyridines using a Rh-Al complex. Both the site- and mono-selectivity are controlled via the pyridine coordination to the Lewis- acidic...

2014 ◽  
Vol 915-916 ◽  
pp. 713-716
Author(s):  
Qing Zhang ◽  
Jing Tian ◽  
Zhi Qi Cao ◽  
Ru Xia Xu ◽  
Zhen Zhen Sun ◽  
...  

In this investigation, Schiff bases aluminum complex was synthesized and used as the initiator in the polymerization of D,L-lactide. The aluminum complex was characterized by infrared spectroscopy (IR), and nuclear magnetic resonance spectroscopy (NMR). The influences of different factors, including reaction time, reaction temperature, and the ratio of D, L-lactide/Al3+ on the synthesis of polylactide were described. The results showed that Schiff bases aluminum complex could be successfully applied in the ring opening polymerization. The optimum condition of the ring opening polymerization of D,L-lactide, which included D,L-lactide/Al3+ (mol/mol) ratio of 250, reaction temperature of 120 °C, and reaction time of 16 hours.


2011 ◽  
Vol 306-307 ◽  
pp. 358-361
Author(s):  
Liu Qing Chen ◽  
Chun Yan Sun ◽  
Xu Guang Liu ◽  
Bing She Xu

We report the synthesis, photophysical investigation, computational studies and electroluminescent(EL) properties of an organic electroluminescent material-Bis(8-hydroxyQuino line) acetylacetone aluminum (Alq2A). It is characterized by 1H NMR, IR and elemental analysis techniques. The absorption and fluorescence spectra of various Alq2A systems including solution in ethanol, powder and thin film on quartz (thickness of 50nm) have also been systematically evaluated. Analysis of the electronic structure of Alq2A calculated by quantum chemical calculations reveals a localization of orbital and the distribution of orbital energy. The results from EL experiments indicate that Alq2A has good electron transport properties as compared with tris(8-hydroxyquinolinato) aluminum (Alq3). Thus, Alq2A is considered to be a superior emitter and electron transporting material for display application compared with Alq3.


2009 ◽  
Vol 48 (23) ◽  
pp. 10892-10894 ◽  
Author(s):  
Zbigniew Florjańczyk ◽  
Wojciech Bury ◽  
Ewa Zygadło-Monikowska ◽  
Iwona Justyniak ◽  
Robert Balawender ◽  
...  

MRS Advances ◽  
2018 ◽  
Vol 3 (64) ◽  
pp. 3979-3985
Author(s):  
Brenda Castaños ◽  
Cecilia Fernández ◽  
Laura Peña-Parás ◽  
Demófilo Maldonado-Cortés ◽  
Juan Rodríguez-Salinas

ABSTRACTGreases are essential in the electrical industry for the purpose of minimizing wear and coefficient of friction (COF) between the components of circuit breakers. Nowadays some researchers have explored the addition of nanoparticles to enhance their tribological properties. In this study, tribological tests were performed on different greases employed for the electrical industry. CuO and ZnO nanoparticles were homogeneously dispersed into the greases, varying their concentration (0.01 wt.%, 0.05 wt.%, and 0.10 wt.%). A four-ball tribotest, according to ASTM D-2266, and a ball-on-disk tribotest, according to ASTM G-99, were performed in order to analyze the wear scar diameter (WSD), COF, wear mass loss and worn area. The worn materials were characterized with an optical 3D profilometer measurement system. Anti-wear properties were enhanced up to 29.30% for the lithium complex grease (LG) with no nanoparticles added, in comparison with the aluminum complex grease (AG), providing a much better tribological performance; in the ball-on-disk tribotests, a 72.80% and a 15.74% reduction in the mass loss and COF were achieved, respectively. The addition of nanoparticles was found to provide improvements of 5.31% in WSD for the AG grease and 34.49% in COF for the LG grease. A pilot test was performed following the security test UL489, achieving a reduction of 45.17% in the worn area achieved by LG grease compared to AG grease.


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