Finally!!! made it..

Don’t you think, it is extremely ridiculous that someone is updating his/her blog after so long period? It is almost 10 months that I could not update my blog regularly. I should apologize for that. I am sorry for this.

However there were some regions behind this gap in blogging. Umm!! My doctor degree in fact. I was pretty busy for my final doctor thesis, company reports, final lab reports and all the official procedures for these.  Finally!!! I made it.

 

My graduate work has mainly focused in the synthesis and spectral properties of pyrene based first member of new class of single and double [4], [5], and [6]-helicene polycyclic aromatic hydrocarbons and Synthesis and characterization of OLED materials based on same. The helically shaped molecules have found applications as potentially useful components in chiral discotic liquid crystalline materials, building blocks for helical conjugated polymers, sensors, dyes, molecular recognition and more fascinatingly as catalysts and ligand in asymmetric synthesis because of their rigid structure and high optical stability.

 

Adopting the improved methods and techniques for the synthesis of potentially useful helicene compounds was my research motto during the doctoral course. During this course; we established a novel concept to obtain helicene compounds. Applying polycyclic aromatic hydrocarbons as the core material for the synthesis of helicene compounds have not been reported to that extent. For this proposed; particularly we have selected pyrene as core material for the synthesis of [4], [5], and [6] mono and bis-helicenes with lots of possibilities of extending that helicene framework to the higher members. Synthesis of helicene motifs around the pyrene core molecules is the novel procedure and techniques to get desired helicene compounds having unique molecular architecture consequently novel class of polycyclic aromatic hydrocarbons. Most importantly, we have selected pyrene as core material because of its unique fluorescence properties that have been using as fluorescence probe since long.

 

The synthesis strategies included the regioselective formylation of pyrene moiety at novel positions and consecutive conversion of formylated pyrenes to the corresponding phenylethenyl pyrenes using Wittig reaction and followed by photo induced cyclization. In order to establish their application; the photo physical properties of synthesized compounds were carefully examined  and characterized. The results obtained through inspecting the absorption and emission spectra of these compounds; indicate that the extension of π-conjugation in these pyrene chromophores through photo induced cyclization serves to shift the wavelength of absorption and fluorescence emission into the pure-blue visible region. Single- crystal X-ray analysis indicated the two bulky t-Bu groups on the pyrene molecule at the 2- and 7-positions play a very important role in inhibiting the π-stacking interactions between neighboring pyrene units, and solved the solubility problems of synthesized helicenes. These molecules not only emit very bright pure-blue fluorescence but also perfectly soluble in common organic solvents with high stability. Hence, they are promising as blue organic light-emitting materials for the fabrication of OLED devices.

 

I found Ph.D. degree as just a drop of water from entire Pacific Ocean. Still a lot to do ahead and need to experience better chemistry in the future. Playing with chemical and embark upon synthetic procedure became a routine life during this training period that I enjoyed a lot and hope to enjoy in the future too…