Synthesis, Photophysical, Electrochemical and Thermal Studies of 2,3-Bithienylpyrazino[2,3-b]phenazine

Abstract: In this work, 2,3-bithienylpyrazino [2,3-b]phenazine [BTPP] was synthesized and its photophysical, electrochemical and thermal properties was studied and compared with 2,3-bithienylquinoxaline [BTQ] and 2,3-bithienylbenzo[g]quinoxaline [BTBQ]. The photophysical studies revealed that BTPP emit in the green region at λ max 551 nm. Electrochemical studies show that the ionization potential (HOMO) and electron affinity (LUMO) of BTPP are -5.49 eV and -3.15 eV respectively and are comparable to commonly used electron acceptor/transporter. The optical energy band gap of BTPP is 2.34 eV. Thermogravimetric analysis showed that BTPP possess good thermal stability

Stability-Indicating RP-HPLC Method for Analysis of Paracetamol and Tramadol in a Pharmaceutical Dosage Form

A simple, isocratic, rapid and accurate reversed phase high performance liquid chromatography method was developed for the quantitative determination of paracetamol and tramadol in commercial medicinal tablets. The chromatographic separation was achieved on an Intersil C18 (250 mm x 4.6 mm, 5μm) column using water pH 3.4 with orthophosphoric acid: methanol (60:40, v/v) as a mobile phase, and UV detection at 228 nm. The chromatographic resolutions between paracetamol and tramadol were found greater than five. The linear range for paracetamol and tramadol were 20.8–39.0 μg/ml and 2.4–4.5 μg/ ml was obtained with correlation coefficients ≥0.999 for each analyte. The retention time were found to be 2.1 and 3.9 min for tramadol and paracetamol respectively. Paracetamol and tramadol was subjected to stress conditions (hydrolysis (acid, base) oxidation, photolysis and thermal degradation) and the stressed samples were analyzed by use of the method. The major degradation was observed in acid and minor in base, thermal, oxidation and photolysis. The forced degradation studies prove the stability indicating power of the method

An efficient method for allylation of ketones with tetra-allylstannane

A variety of ketones undergo an allylation reaction with tetra-allyltin in the presence of a catalytic amount of Cu(OTf)2 or Sn(OTf)2. The method was found to be superior to most of the known methods, which are efficient only with aldehydes

Enantioselective phenylacetylene addition to aldehydes induced by Cinchona alkaloids

Enantioselective addition of phenylacetylene to various aldehydes was studied in the presence of inexpensive and commercially available Cinchona alkaloids. A maximum of 85% ee was obtained using cinchonidine in the presence of Ti(OiPr)4

Enantiomerically pure N-aryl-β-amino alcohols by enzymatic resolution

N-Aryl-β-amino acetates, obtained by opening epoxides with aromatic amines followed by acetylation of the hydroxyl group, were resolved using crude pig liver esterase (PLE) enzyme in DMSO in high enantiomeric excess

An efficient method for aromatic Friedel–Crafts alkylation, acylation, benzoylation, and sulfonylation reactions

Aromatic electrophilic substitution reactions such as alkylation, acylation, benzoylation, and sulfonylation were studied in the presence of a catalytic amount of Cu(OTf)<SUB>2</SUB> and Sn(OTf)<SUB>2</SUB>. Cu(OTf)<SUB>2</SUB> was very efficient for alkylation, acylation, and benzoylation reactions. However, in case of sulfonylation reactions, Sn(OTf)<SUB>2</SUB> gave better results

Acridone-amine D-A-D thermally activated delayed fluorescence emitters with narrow resolved electroluminescence and their electrochromic properties

Acridones have found their role in luminescent materials for OLEDs. Most interestingly, showing potential as weak charge transfer thermally activated delayed fluorescence (TADF) emitters, providing narrow photoluminescence. In this work, we present a comprehensive study of donor-acceptor-donor (D-A-D) acridone-amine derivatives showing TADF and UV electrochromic properties. Structure-property relationships are studied using electrochemical and spectroelectrochemical methods as well as using photophysical characterization. Most successful emitters are used as luminescent materials in OLED, showing narrow (FWHM = 66-85 nm) electroluminescence in the green region with maximum EQE = 5.4%

Breeding and molecular approaches for evolving drought-tolerant soybeans

Soybean [Glycine max (L.) Merr] is an agronomically important oilseed crop in the world and an important source of protein and oil for both humans and animals. In addition, soybean is also becoming a major crop for bio-diesel production. Therefore, demand for soybean is increasing continuously worldwide. Soybean enriches the soil by fixing atmospheric nitrogen through symbiotic interaction with Rhizobia. With increasing challenges posed by climate change, it is predicted that incidents of drought will be more frequent and severe and it will further reduce crop yields. Abiotic stresses such as drought cause severe losses to soybean productivity worldwide by adversely affecting the plant growth, development, and yield. Introgression of genes controlling drought adaptive traits, yields related traits and root system architecture traits by breeding and molecular approaches will be very useful for enhancing drought stress tolerance in soybean, leading to cultivar development. Elucidation of function of genes and their integration in soybean genotypes by molecular breeding and genomic approaches and utilizing robust phenotyping tools to evaluate drought adaptive traits will be crucial for understanding response of soybean plants to drought stress. Recent advances in genomics lead identification, functional characterization, and introgression of genes associated with adaptation of soybean plants to drought stress. In order to perform genetic and genomic analysis, molecular markers have been employed on RIL or F2 populations. In addition, the genome typified with single nucleotide polymorphisms (SNPs) and its utilization in molecular breeding applications like QTL mapping, positional cloning, association mapping studies, genomic selection and genome editing is gaining impetus. Thus, the rapid development of soybean genomics and transcriptomics has provided tremendous opportunity for the genetic improvement of soybean for drought tolerance with yield stability