Annual Report 2004-2005

Scientific Research

Chemical Sciences

Support to frontier areas of research in chemical sciences continued during this year. Several projects in contemporary areas such as nanomaterials, protein folding, ionic liquids, new organometallic reagents etc. received funding. The sub-area wise projects funded are given below:

Organic Chemistry

• Study of novel multicomponent reactions involving nucleophilic carbenes and related chemistry.
• This work may result in novel heterocyclic compounds showing biological activity.
• A novel atom economical route has been proposed for organic stereoselective processes using Baylis-Hillman reaction. This study would be directed towards synthesis of important biologically active molecules via the Baylis-Hillman methodology.
• Design and synthesis of dual PPAR ã /á agonists having novel carbazole moieties with antidiabetic and hypolipidemic activity. The compounds obtained would be screened for antihyperglycemic and anti hyperlipidemic activities.
• Design, synthesis and biological studies of neoglycoconjugates. Different functionalized molecules, both cyclic and linear would be synthesized using carbohydrates as scaffold and their biological activities would be studied.
• Catalytic asymmetric 1,3-dipolar cycloaddition reaction of azomethineylides: Application towards the asymmetric total synthesis of (+)- and (-)-spirotryprostatins. Novel synthetic methodologies for synthesizing chiral pyrrolidine will be developed and this methodology will be applied towards synthesis of potent antimitotic agents, spirotryprostatins.
• Enzyme-mediated resolutions and deracemizations in ionic liquids. Application of enzymes such as proteases, lipases and substilisin in ionic liquids would be explored for the preparation of commercially important agrochemicals and pharmaceutical products.
• Novel bile acid derived dendritic structures: Design, synthesis, properties and potential applications. Synthesis of novel bile acid derived dendritic structures would be undertaken and their application as drug conjugates, light harvesting system and as drug catalysts will be investigated.
• New organometallic reagents for green chemistry: An attempt would be made to develop organobismuth reagents as potential organometallic alternative reagent for organic synthesis.
• Synthesis of chiral hydrocyanins as intermediates for industrially important bio-active compounds through chiral catalytic route. This involved design and synthesis of chiral inorganic metal complexes and their application as catalyst in the preparation of commercially useful chiral cyanohydrins.

The research highlights of the projects are as follows:

• A Patent has been filed for improved enzymatic process for the preparation of amino acyl esters of mono and disaccharides;
• A new route to C-aryl glycosides was achieved which may open up the possibility of entry into C-nucleosides;
• A Patent has been filed for a chemoenzymatic process for the stereoselective preparation of ®-ã-amino-â-hydroxy butyric acid (R-GABOB) and ® -carnitine;
• Studies of glycoside cluster effect in carbohydrate-protein interaction have led to better understanding of complex carbohydrate mediated biological processes;
• Short and efficient methods have been developed for the synthesis of scyllo-inositol and its thoformate derivatives;
• Several newer ionic liquids based on imidazolium salts were synthesized and their inherent acidity has been used as reaction media/promoters to environment friendly processes with minimal or no waste;
• A new T-tecton keto phenol 8 was developed to build host-guest ladder networks; and
• New fluorescent and chiral GPI and PI probes have been prepared to address important questions regarding membrane organization and biology.

Inorganic Chemistry

The projects received in the five identified areas (aqueous organometallic chemistry; molecular precursors for advanced inorganic materials; metalloenzymes and their mimics; green chemistry; and f-block elements) were considered and four were funded (two in the area of “metalloenzymes and their mimics”; one each in the area of “molecular precursors for advanced inorganic materials” and “f-block elements”). Among the two projects in the area of “metalloenzymes and their mimics” one deals with mimicking of structural and functional aspects of iron and manganese containing metalloproteins using extradiol cleaving enzymes, while the other deals with the synthesis of selenocysteine derivatives and use them for biomimetic studies. This study is expected to throw some light on the role of selenium in biological systems. A project on “molecular precursor for advanced inorganic materials” deals with the synthesis of molecular container of different size and shape through self-assembly of chiral transition metal complexes; while the project in the area of “ fblock elements” deals with the synthesis of new 4f and 5f inorganic compounds using hydrothermal/solvo thermal methods and study their luminescence properties for possible use as fluorescence markers for DNA.

In addition, projects in other areas are as below:

• Design, synthesis and cation recognition study of fluorescent molecular sensors. This study is expected to help in development of fluorescent probe for alkali, alkaline earth and toxic metal ions.
• Mapping the reaction coordinate for the oxidative addition of molecular hydrogen to a metal center. This study would help in designing systems that may show improved efficiency and better catalytic activity.
• Green chemistry with water-tolerant reactions and reagents. The development of organic reactions in water will contribute significantly to the progress of green chemistry.
• Design and development of peroxo-metal mediated environmentally benign reagents and reactions. A greener (environment friendly) synthesis of chloro compounds is proposed.
• Development of new procedure for the synthesis of optical active organocobaloximes and study their Co-C bond reactivity in molecular oxygen insertion reactions and in hydrogenation reactions. This study is a first attempt to exploit the role of organocobaloximes for this purpose.
• Synthesis of new class of polynuclear ruthenium and osmium complexes in different valence states and study their photophysical and electrochemical properties. This study might possibly lead to new materials having high degree of nonlinear optical properties.
• Synthesis of novel late transition metal complexes with N-heterocyclic carbene based legands with the aim of designing new catalysts for olefin polymerization and co-polymerization. These complexes are expected to be air and moisture stable and would thus be an improvement over the existing polymerization catalysts.
• Synthesis of a range of redox active copper and other transition metal complexes having ligand system containing photo synthesizing abilities and study photoinduced DNA cleaving activity. The study has implications in the photodynamic therapy and cancer treatment. The research highlights of projects are given below:
• New first generation metallodendritic supramolecular assemblies have been developed.
• It has been shown for the first time that the hydrolysis of commercially available air and moisture stable early transition metal compounds, Cp2MCl2 (M=Ti, V, or Zr), can be advantageously used for generating active catalysts for aqueous emulsion polymerization.
• Some new chiral cyclophosphazenes have been synthesized and they were structurally characterized.
• Novel Ru-pac complexes were synthesized and few of them showed anti-tumour activity.
• Efficient routes have been developed for synthesis of polynuclear complexes of platinium metals.
• Efficient processes for recovery of uranium and palladium from low grade minerals and seawater have been developed.
• High Performance Liquid Chromotography system has been sanctioned at IISc, Bangalore (Figure 2.3). This system will be used for separation and purification of selenium containg aminoacids, peptides and proteins.

Physical Chemistry

High precision crystal structure studies on some ferroic crystals to obtain precise charge density maps as a function of temperature across their phase transitions.

Investigation of the formation of C-H —H-B dihydrogen bond clusters between various substituted benzenes and boranetrimethylamine in gas phase using electronic and vibration spectroscopy methods. Dehydrogenation reaction via dry hydrogen bonded intermediates as a possible method to active C-H bonds will be investigated. It is an interesting study from the point of view of understanding weak inter molecular reactions in chemistry of di-hydrogen bond systems as it has not been well understood

• Studies of electron and proton transfer processes in ionic liquids have been funded. New class of ionic liquids based on pyrrolidinum salts, which are expected to have better expected transparancy in the near UV region, would be prepared and their photophysical properties would be investigated.
  
• Synthesis of mono and bimetallic nano particles in controlled conditions, study of dsorption of biomolecules on the surface of nanoparticles and the interaction of nano particles with biomolecules in organized media. This study is expected to yield nanomaterials with different size and shape distribution which is extremely important in nano science.
• Investigation of the dynamics of water surrounding a protein and the effect of water during the folding of proteins. The free energy landscapes of small proteins through minimalistic models, kinetics of association of proteins and to develop a theory of protein folding are attempted. This study has implications in drug discovery
• Development of soft-computing methods for bound state electronic structure calculations.

Green Chemistry Programme

The Green Chemistry programme took concrete shape during the year. A separate Task Force was constituted to promote this area. A Seminar-cum-Workshop was organized at IICT, Hyderabad in September, 2004. Around 100 researchers from academic institutions and industry participated in the event. Lectures were delivered by eminent people practicing Green Chemistry in the workshop. Another Workshop in the eastern region is planned in February, 2005 at IIT, Guwahati.

Proposals were invited in the area of Green Chemistry under two categories: (i) Open-ended and (ii) industry collaborative projects. Under the industry collaborative projects category, two projects have been recommended for funding. One project related to conversion of waste material into useful products. This proposal is for conversion of bulk circuit waste coming from Jhamarkotra plant, Rajasthan into calcium magnesium phosphate fertilizer. Rajasthan State Mines and Minerals Limited is contributing 30% of the recurring cost to this project. Another project is on development of novel ecofriendly bromine-less bromination protocols, brominating agents and development of newer catalysts for a variety of oxidations. This project will be partly funded by Ranbaxy Limited.