Organic Donor-Acceptor Complexes As Potential Semiconducting Materials.

In this review article, the synthesis, characterization and physico-chemical properties of the organic donor-acceptor complexes are highlighted and a special emphasis has been placed on developing them as semiconducting materials. The electron-rich molecules, i. e.

Application of N-heterocyclic carbene-Cu(I) complexes as catalysts in organic synthesis: a review.

N-Heterocyclic carbenes (NHCs) are a special type of carbenes in which the carbene carbon atom is part of the nitrogen heterocyclic ring. Due to the simplicity of their synthesis and the modularity of their stereoelectronic properties, NHCs have unquestionably emerged as one of the most fascinating and well-known species in chemical science. The remarkable stability of NHCs can be attributed to both kinetic as well as thermodynamic effects caused by its structural features.

Dienophilic reactivity of 2-phosphaindolizines: a conceptual DFT investigation.

The >C=P- or -N=P- functionality in 1,3-azaphospholo[1,5-]pyridine, named as 2-phosphaindolizine and its 1- and 3-aza derivatives act as dienophiles and undergo Diels-Alder reactions with 1,3-dienes. However, the dienophilic reactivity is affected by the nature of the substituent groups on the two sides of the σ,λ-P atom and also by the presence of more nitrogen atom(s) in the five-membered ring. The conceptual density functional theory (DFT) calculations have been used in recent years to predict the reactivity of organic molecules in reactions.

A new cross-conjugated mesomeric betaine.

Cross-conjugated mesomeric betaine (CCMB) has been defined as the dipolar species in which positive and negative charges are restricted to different parts of the molecule. In contrast to indolizine which undergoes [8+2] cycloaddition with dimethyl acetylenedicarboxylate (DMAD), its 1-aza analogue, namely imidazo[1,2-]pyridine reacts with the same reagent to afford the first representative of the CCMB isoconjugate with the odd non-alternant hydrocarbon anion. The structure of the product could be assigned on the basis of the NMR and HRMS results.

Recent advances in organocatalytic asymmetric aza-Michael reactions of amines and amides.

Nitrogen-containing scaffolds are ubiquitous in nature and constitute an important class of building blocks in organic synthesis. The asymmetric aza-Michael reaction (aza-MR) alone or in tandem with other organic reaction(s) is an important synthetic tool to form new C-N bond(s) leading to developing new libraries of diverse types of bioactive nitrogen compounds. The synthesis and application of a variety of organocatalysts for accomplishing highly useful organic syntheses without causing environmental pollution in compliance with 'Green Chemistry" has been a landmark development in the recent past.

Synergy between Experimental and Theoretical Results of Some Reactions of Annelated 1,3-Azaphospholes.

Computational calculations have been used successfully to explain the reactivity of the >C=P- functionality in pyrido-annelated 1,3-azaphospholes. Theoretical investigation at the Density Functional Theory (DFT) level shows that the lone pair of the bridgehead nitrogen atoms is involved in extended conjugation, due to which electron density increases considerably in the five-membered azaphosphole ring. The electron density in the azaphosphole is further enhanced by the presence of an ester group at the 3-position making the >C=P- functionality electron-rich.

Cross-sectional study to assess the need to commence opportunistic screening of women for cervical cancer presenting with sexually transmitted disease in Western India.

This study examines the prevalence of suspected cervical cancer (established through the use of visual inspection with Lugol's Iodine - VILI) among outpatients attending Surat Municipal Institute of Medical Education & Research Hospital, India. A cross-sectional study was conducted on 356 patients; 178 with an established sexually transmitted disease (STD) and 178 patients without. Patients with positive results were investigated with cervical biopsy; out of 356 patients, 21.

Cross-sectional study on socio-demographic and clinical correlates of depression among human immunodeficiency virus-positive patients in Surat City, Western India.

Introduction: Surat has the highest incidence of human immunodeficiency virus/acquired immune deficiency syndrome (HIV/AIDS) in Gujarat, the main reason being its large migrant population. Mental health in HIV/AIDS has most often been a topic of neglect all over the world. This study attempts to assess the magnitude of depression and the socio-demographic and clinical variables associated with it in HIV-positive patients.

Vaccine Wastage Assessment After Introduction of Open Vial Policy in Surat Municipal Corporation Area of India.

Background: As per the vaccine management policy of the Government of India all vaccine vials opened for an immunization session were discarded at the end of that session, irrespective of the type of vaccine or the number of doses remaining in the vial prior to 2013. Subsequently, open vial policy (OVP) was introduced in 2013 and should reduce both vaccine wastage as well as governmental healthcare costs for immunization. This study evaluates the vaccine wastage after introduction of the OVP and its comparison with the previous study of vaccine wastage in Surat city before implementation of OVP.

Asymmetric Diels-Alder reaction with >C=P- functionality of the 2-phosphaindolizine-η(1)-P-aluminium(O-menthoxy) dichloride complex: experimental and theoretical results.

The Diels-Alder reaction of the 2-phosphaindolizine-η(1)-P-aluminium(O-menthoxy) dichloride complex with dimethylbutadiene was investigated experimentally and computationally. The >C=P- functionality of the complex reacts with 2,3-dimethylbutadiene with complete diastereoselectivity to afford [2 + 4] cycloadducts. Calculation of the model substrate, 3-methoxycarbonyl-1-methyl-2-phosphaindolizine-P-aluminium(O-menthoxy) dichloride (7a), at the DFT (B3LYP/6-31+G*) level reveals that the O-menthoxy moiety blocks the Re face of the >C=P- functionality, due to which the activation barrier of the Diels-Alder reaction of 7a with 1,3-butadiene, involving its attack from the Si face, is lower.

Diels-Alder Reaction of phosphaethene with 1,3-dienes: an ab initio study.

Computations on Diels-Alder (DA) reactions of phosphaethene with 1,3-butadiene and with isoprene reveal asynchronous transition structures. The DFT (B3LYP/6-311+G) activation energies of these reactions, 12-14 kcal/mol, are much lower than that of the parent ethene-butadiene reaction, 28 kcal/mol, even though the exothermicities of all lie in the same range, from -29 to -33 kcal/mol. The transition states (TSs) for the phosphethene-butadiene or isoprene DA reactions are earlier than the TSs of the butadiene-ethene cycloaddition.