RSC Advances Blog

Organic light emitting diodes (OLEDs) are highly promising as energy-efficient lighting and in flat panel displays. Much work is being done around the world and a recently accepted article in RSC Advances, by Yuezhong Meng, Shuanjin Wang and colleagues in China, reports on the preparation of a yellow-emitting iridium complex [Ir(DMP)₃] for use in OLEDs.

An OLED doped with 2 wt% of the complex produced yellow emission at 576 nm with a maximum quantum efficiency of 8.7% at 5.93 mA/cm², and CIE coordinates of (0.49, 0.50). Yellow OLEDs are of key importance for the production of white OLEDs (or WOLEDs) for solid-state lighting applications. Details of the synthesis, characterisation, OLED fabrication and performance are given.

This article is free to access:

Structure and Properties of Highly Luminescent Yellow Emitting Material for OLED and Its Application, Shakil Mulani, Min Xiao, Shuanjin Wang, Yawen Chen, Junbiao Peng and Yuezhong Meng, RSC Adv., 2012, DOI: 10.1039/C2RA21951D

Stay up-to-date with the latest content in RSC Advances by registering for our free table of contents alerts.

By Sara Coles

Scientists from China have identified and characterised the elusive gold(I) hydrates that result from the common gold(I) pre-catalyst Ph₃PAuOTf.

Gold(I) complexes have been the subject of a great deal of attention in recent year due to their application in a broad range of chemical reactions and their excellent catalytic activity.  Their advantages over some other metal catalysts includes their insensitivity to moisture, therefore not requiring a completely ‘dry’ reaction environment and instead can even be used in reactions with water as the solvent. 

Amongst some of the ambiguous aspects of the catalytic species actually involved in these transformations, the exact role of water, and whether it reacts with the gold complexes, is uncertain.  This is important in order to gauge the impact water has on the catalytic activity and the turnover frequency.  In this work, Biao Yu and Yu Tang from the Shanghai Institute of Organic Chemistry, China, identified two gold(I) hydrates from the Ph₃PAuOTf pre-catalyst – [Ph₃PAu(OH₂)]⁺TfO⁻and [(Ph₃PAu)₂(OH)₂]²⁺(TfO⁻)₂, resulting in the disclosure of the equilibria between gold oxo species in wet solutions.  The results presented here help to explain further the stability of some gold complexes in water and the instability of others.

Read the full article for free!

Identification of (phosphine)gold(I) hydrates and their equilibria in wet solutions, Yu Tang and Biao Yu, RSC Adv., 2012, DOI: 10.1039/C2RA22282E

Stay up-to-date with the latest content in RSC Advances by registering for our free table of contents alerts.

This review article by Jean-Jacques Vasseur, François Morvan, Yann Chevolot and colleagues from France looks at the design and applications of DNA glycoclusters and DNA-based carbohydrate microarrays, combining the automated chemistry of DNA and “click” chemistry. 

The authors illustrate that DNA chemistry (phosphoramidite as well as H-phosphonate) can be used to synthesis glycomimetics via a very efficient copper(I) catalyzed azide alkyne cycloaddition (“click” chemistry). This gives quick access to a range of glycomimetics with different topologies, such as linear and crown-like.  Due to the DNA tag present, the glycomimetics can easily be immobilized on microarrays to analyse their interactions and binding-properties with lectins.  The authors demonstrate that DNA glycoarrays relying on DNA directed immobilization presents several advantages over conventional immobilization techniques.

Read the full article for free!

DNA glycoclusters and DNA-based carbohydrate microarrays: From design to applications, François Morvan, Sébastien Vidal, Eliane Souteyrand, Yann Chevolot and Jean-Jacques Vasseur, RSC Adv., 2012, DOI: 10.1039/C2RA21550K

This article is part of a web-themed issue accross RSC Advances, ChemComm and Organic & Biomolecular Chemistry ‘Nucleic acids: new life, new materials‘ dedicated to the memory of Professor Har Gobind Khorana (1922 – 2011), acknowledging his legacy to the nucleic acids community.  Read the collection so far here.

A straightforward route to synthesize pyrrolylBODIPY dyes, which can be used for fluorescent imaging, from acid chloride and excess pyrrole has been developed by scientists in China.

Pyrrolyldipyrromethenes contain the same core structure as the natural red pigment prodigiosin, and have received a lot of interest due to their broad range of biological activities.  When pyrrolyldipyrromethene is complexed with boron, the result is long wavelength absorbing and emitting fluorescent dyes.  In the synthesis of these dyes, the key step is the synthesis of the 2,2′-bipyrrole unit which often involves multiple steps and the use of expensive catalysts.

In this work, Erhong Hao, Lijuan Jiao and colleagues from Anhui Normal University, China, report that by reacting acyl chloride and excess pyrrole in dichloromethane under an oxygen atmosphere, to give the pyrrolylBODIPY dyes after about 10 hours. The application of these dyes to the fluorescent imaging of living-cells was then tested and the results suggested that the dyes were non-toxic and could easily be taken up by the cells. 

Read the full article for free!

One-pot efficient synthesis of pyrrolylBODIPY dyes from pyrrole and acyl chloride, Min Zhang, Erhong Hao, Yajun Xu, Shengzhou Zhang, Hongnian Zhu, Qi Wang, Changjiang Yu and Lijuan Jiao, RSC Adv., 2012, DOI: 10.1039/C2RA22203E

You may also be interested in these articles…

Synthesis and spectroscopic properties of bodipy dimers with effective solid-state emission, Lizhi Gai, Hua Lu, Bin Zou, Guoqiao Lai, Zhen Shen and Zhifang Li, RSC Adv., 2012, 2, 8840-8846

Thienyl-substituted BODIPYs with strong visible light-absorption and long-lived triplet excited states as organic triplet sensitizers for triplet–triplet annihilation upconversion, Yinghui Chen, Jianzhang Zhao, Lijuan Xie, Huimin Guo and Qiuting Li, RSC Adv., 2012, 2, 3942-3953

Stay up-to-date with the latest content in RSC Advances by registering for our free table of contents alerts.

There has recently been a lot of effort devoted to developing scaffolds that can mimic naturally occurring microenvironments to promote tissue regeneration.  These scaffolds need to provide not only a three-dimensional (3D) structural support but also nanotextured surfaces which comprise of a fibrous network for cell adhesion and signaling.

In this review article Shang-Tian Yang and colleagues from The Ohio State University, USA , look at the influence of 3D microstructures and nanotopographies on cellular functions – cell adhesion, proliferation, morphogenesis and differentiation.  The authors then discuss the recent developments in fabrication methods to produce 3D fibrous scaffolds and examples of their applications.

Simply register or login to download the full article for free:

Three-dimensional fibrous scaffolds with microstructures and nanotextures for tissue engineering, Robin Ng, Ru Zang, Kevin K. Yang, Ning Liu and Shang-Tian Yang, RSC Adv., 2012, DOI: 10.1039/C2RA21085A

Stay up-to-date with the latest content in RSC Advances by registering for our free table of contents alerts.

Hydrophobin proteins (also known as fungal adhesion proteins) adsorbed and formed a lubricating monolayer film on a stainless steel surface.

The use of water as a lubricant in certain applications holds several advantages due to its environmentally-safe and non-toxic nature, but employing it is challenging due to its low viscosity.  In this study, scientists from Finland and Germany led by Timo Hakala looked at using hydrophobin proteins to aid water lubrication between two stainless steel surfaces. 

The protein layer that was formed on the steel significantly reduced the friction and wear on the two steel surfaces.  A higher water content in the film could be achieved by attaching a carbohydrate moiety to the protein, which resulted in a decrease in the friction and wear on the steel.  The water content could be controlled by varying the conditions. 

Simply register to download the full article for free:

Adhesion and tribological properties of hydrophobin proteins in aqueous lubrication on stainless steel surfaces, Timo J. Hakala, Päivi Laaksonen, Vesa Saikko, Tiina Ahlroos, Aino Helle, Riitta Mahlberg, Hendrik Hähl, Karin Jacobs , Petri Kuosmanen, Markus B. Linder and Kenneth Holmberg, RSC Adv., 2012, DOI: 10.1039/C2RA21018E

Stay up-to-date with the latest content in RSC Advances by registering for our free table of contents alerts.

Scientists from Singapore have investigated the effect of various salts on facilitated transport membranes for carbon dioxide (CO₂) separation.

The addition of salts to polymeric membranes has proven to be a practical way to improve their permselectivity for gas separation. In this work, Rong Wang and Lizhi Zhang from the Nanyang Technical University looked into whether or not this could be applied to CO₂separation.  They found that with the addition of NaF salt, the permeance of N₂ was significantly reduced (by a factor 9.4) – far more so than for CO₂ (reduced by a factor of 1.5). 

The authors also introduced polyoxometalates (POMs) as oxysalts into the membranes.  Whilst the permeance of CO₂through the membranes was much lower, the permselectivity of CO₂ over N₂was much greater.  Due to their unique properties, POMs can be considered as attractive additives to membranes for CO₂ separation.

Click on the link below to read this article for free!

Salting-out effect on facilitated transport membranes for CO₂separation: From fluoride salt to polyoxometalates, Lizhi Zhang and Rong Wang, RSC Adv., 2012, DOI: 10.1039/C2RA20882B

A team from Alabama, USA have reported a highly selective extraction of the uranyl ion from aqueous solution via η²  coordination using hydrophobic amidoxime-functionalized ionic liquids.

The world’s oceans contain approximately one thousand times the terrestrial supply of uranium, but a selective, cheap and insoluble extractant must be developed to overcome the energetic and economic challenge of the low concentrations in seawater and the variety of interfering ions.  In the 1980s, after studying over 200 adsorbents, it was reported that the amidoxime functional group, RC(NH₂)(=NOH), appended to polyacrylonitrile was highly selective towards uranium.

Though well-studied, the coordination of amidoxime to the uranyl ion is not well understood. In this paper, Robin Rogers and his team from the University of Alabama have been able to utilize the functionality of ionic liquids to demonstrate the controversial coordination mechanism for extraction of uranium from seawater by amidoxime extractants.  They have demonstrated, through extraction, spectroscopic, and crystallographic studies that hydrophobic, amidoxime-functionalized ionic liquids selectively extract the uranyl ion from aqueous solution via η² coordination. 

Simply register to download the full article here:

Highly selective extraction of the uranyl ion with hydrophobic amidoxime-functionalized ionic liquids via η2 coordination
Patrick S. Barber ,  Steven P. Kelley and Robin D. Rogers
RSC Adv., 2012, Advance Article
DOI: 10.1039/C2RA21344C