Pathway-Dependent Control of Chiral Phases for Higher Performance and Inverted Circularly Polarized Luminescence.

Chiral luminescent materials have garnered increasing attention for their exceptional ability to emit circularly polarized luminescence (CPL) along with their excellent applications. Here, a cyclohexylidene scaffold was conceptualized as a chiral source for developing higher performance CPL materials in term of simultaneously enhanced quantum yields (PLQYs) and dissymmetry factor. It was found that the axially chiral scaffold attached with a cyanostilbene showed a pathway dependent assembly route to form chiral luminescent liquid crystals and crystal upon fast and slow cooling, respectively.

Highly Selective Turn-on Fluorescence Sensor for Cd Ions by Tripodal Organic Ligand.

Organic fluorescence sensor for selectively detecting and quantifying toxic heavy metal ions has received significant interest due to their environmental hazards. Herein, we have designed and synthesized a simple tripodal Schiff base ligand (1) based on hydroxy-naphthaldehyde and tris(2-aminoethyl)amine (TREN) and demonstrated highly selective turn-on fluorescence sensing of Cd ions. The free ligand did not show any fluorescence in DMF.

Methoxy substituent facilitated wide solvatofluorochromism, white light emission, polymorphism and stimuli-responsive fluorescence switching in donor-π-acceptor.

Introducing methoxy substituent into triphenylamine-acetophenone based donor-π-acceptor fluorophore, 3-(4-(diphenylamino)phenyl)-1-phenylprop-2-en-1-one (1), produced strong solvatofluorochromism including white light emission, fluorescent polymorphs and mechano-responsive fluorescence switching. The unsubstituted and methoxy substituted compounds displayed strong solvent polarity mediated tunable emission in the solution. Interestingly, 3-(4-(diphenylamino)phenyl)-1-(4-methoxyphenyl)prop-2-en-1-one (2) and 3-(4-(diphenylamino)-2-methoxyphenyl)-1-(4-methoxyphenyl)prop-2-en-1-one (3) showed single molecule white light emission in DMSO and ethanol, respectively.

A case study of real-world tailpipe emissions for school buses using a 20% biodiesel blend.

Numerous laboratory studies report carbon monoxide, hydrocarbon, and particulate matter emission reductions with a slight nitrogen oxides emission increase from engines operating with biodiesel and biodiesel blends as compared to using petroleum diesel. We conducted a field study on a fleet of school buses to evaluate the effects of biodiesel use on gaseous and particulate matter fuel-based emission factors under real-world conditions. The field experiment was carried out in two phases during winter 2004.