Deep Red to Near‐Infrared Emitting Rhenium(I) Complexes: Synthesis,Characterization, Electrochemistry,Photophysics, and Electroluminescence Studies

A series of triarylamine‐containing tricarbonyl rhenium(I) complexes, [BrRe(CO)₃(N^N)] (N^N=5,5′‐bis(N,N‐diaryl‐4‐[ethen‐1‐yl]‐aniline)‐2,2′‐bipyridine), has been designed and synthesized by introducing a rhenium(I) metal center into a donor‐π‐acceptor‐π‐donor structure. All of the complexes showed an intense broad structureless emission band in dichloromethane at around 680–708 nm, which originated from an excited state of intraligand charge transfer (³ILCT) character from the triarylamine to the bipyridine moiety. Upon introduction of the bulky and electron‐donating pentaphenylbenzene units attached to the aniline groups, the emission bands were found to be red shifted. The nanosecond transient absorption spectra of two selected complexes were studied, which were suggestive of the formation of an initial charge‐separated state. Computational studies have been performed to provide further insight into the origin of the absorption and emission. One of the rhenium(I) complexes has been utilized in the fabrication of organic light‐emitting diodes (OLEDs), representing the first example of the realization of deep red to near‐infrared rhenium(I)‐based OLEDs with an emission extending up to 800 nm.     

Simultaneous separation and determination of 16 testosterone and nandrolone esters in equine plasma using ultra high performance liquid chromatography-tandem mass spectrometry for doping control

The potential for using testosterone and nandrolone esters in racehorses to boost the biological concentrations of these steroids and enhance athletic performance is very compelling and should be seriously considered in formulating regulatory policies for doping control. In order to regulate the use of these esters in racehorses, a sensitive and validated method is needed. In this paper, we report such a method for simultaneous separation, screening, quantification and confirmation of 16 testosterone and nandrolone esters in equine plasma by ultra high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). Analytes were extracted from equine plasma by liquid-liquid extraction using a mixture of methyl tert-butyl ether and ethyl acetate (50:50, v/v) and separated on a sub-2 micron C(18) column. Detection of analytes was achieved on a triple-quadrupole mass spectrometer by positive electrospray ionization mode with selected reaction monitoring (SRM). Mobile phase comprised 2 mM ammonium formate and methanol. Deuterium-labeled testosterone enanthate and testosterone undecanoate were used as dual-internal standards for quantification. Limits of detection (LOD) and quantification (LOQ) were 25-100 pg/mL and 100-200 pg/mL, respectively. The linear dynamic range of quantification was 100-10,000 pg/mL. For confirmation of the presence of these analytes in equine plasma, matching of the retention time with mass spectrometric ion ratios from MS/MS product ions was used. The limit of confirmation (LOC) was 100-500 pg/mL. The method is sensitive, robust, selective and reliably reproducible.     

New functional inorganic polymers containing phosphorus

The C=C bond plays numerous roles in polymer science. This moiety is used as a precursor to polymers by addition polymerization and has been incorporated into π-conjugated polymers. The addition polymerization reaction has been extended to P=C bonds and the first example of a poly(methylenephosphine) has been prepared. The new macromolecule is of moderate molecular weight (ca. 10⁴ g/mol) and the oxidized polymers are air-stable. Poly(p-phenylenephosphaalkene), the first π-conjugated polymer containing P=C bonds in the backbone, has been prepared. The UV/Vis spectrum of this polymer shows a red shift in λ_max when compared with molecular model systems.