Annual Report 2005-2006

Science & Engineering Research Council

Chemical Sciences

Support to frontier areas of research and launching of new initiatives in bioinorganic chemistry were the highlights of the year.

Organic Chemistry

New projects sanctioned are:

• Exploring new concepts for asymmetric catalysis in aqueous media. Synthesis of new chiral ligands alongwith design of water soluble recyclable catalysts would be undertaken in the project.
• Synthetic studies directed towards the preparation of cyclitols, quercitol, aminocyclitols and their derivatives from naturally occuring inositols. The study will throw more light on biological activities of cyclitols and aminocyclitols.
• Studies on chemical synthesis of ureidopeptides: Nafmoc-Peptide isocyanates as building blocks for incorporation of urea and thiourea moieties as a replacement of amide bond into peptides. The compounds synthesized would be subjected to usefulness in medicinal chemistry.
• Synthesis of chiral heterocycles from organochalcogen ligands via dianion intermediates. The study may give insight about biological activity of organotin compounds.
• Addition polymerization of olefins and ring-opening polymerization of lactams by single-site catalysts. The outcome would lead to new knowledge generation in current areas of catalyst research relevant to polymer industry.

Figure 2.3: Matrix Assisted Laser Desorption Time of Flight Mass Spectrometer (MALDI TOF MS) at IIT Madras

• Design, synthesis and biophysical characterization of novel secondary structure peptidomimetics. The results could be used in enzyme mimics, drug design, protein- ligand interactions, protein design etc.
• Un-natural amino acids from amino acids. The study could be useful in pharmaceutical applications.
• Development of novel probes based on organic ligands for nucleosides, nucleotides and nucleic acids. The study could help in developing photoactivated DNA cleavaging agents and probes for biological applications.

Research Highlights and achievements in the ongoing projects are as follows:

• An efficient method has been developed for the synthesis of 3(2H)-furanones, some of which are known to exhibit anti tumor properties.
• A patent has been filed for developing an enzymatic method for the preparation of curcumin glycosides.
• A new method has been developed for grafting using microwave irradiation. This method not only saves time but can minimize the use of chemicals for the modification of polysaccharides.
• It has been observed that hydrogels composed of polyvinyl alcohol and coplymers proved to be potential water imbibing matrices. These hydrogels have potential to serve as biomaterials for various biomedical and pharmaceutical applications.
• A hierarchical helical growth of coiled-coil nanostructures has been observed for the first time during the gelation of ?-conjugated systems. This is the first example of gelation-induced CD signal change during self-assembly of conjugated molecules.
• A novel class of functional materials have been designed based on the self-assembly of conjugated molecules which may have potential use as light harvesting materials.
• Supramolecular assemblies in the form of host-guest complexes and stacked sheet structures have been obtained from 1,2,4,5-benzenetetracarboxylic acid and various aza-donor molecules. It has been noted that in the host-guest complexes, water also plays an important role in the formation of the host structure by the acid to accommodate different type of guest molecules.

Inorganic Chemistry

Two workshops were organized in the area of organometallic chemistry and bioinorganic chemistry. As a follow up of the recommendations of these workshops, a special initiative has been launched in bioinorganic chemistry. Under this initiative, twenty research fellowships will be provided for pursuing research in bioinorganic chemistry and research proposals in identified areas will also be invited.

New projects sanctioned are:

• Magneto-structural correlation and electrochemical study. Coordination compounds containing transition metal ions would be synthesized and studied which have potential applications as catalyst, molecular sieves, oxygen carrier etc.
• Hydrolysis of esters by metal complexes of designed ligands: Inorganic and bioinorganic perspectives. The study may lead to better understanding of functional properties of hydrolytic metalloenzymes
• Exploration on organotin carboxylates as a viable building block for constructing homo and heteronuclear supramolecules: Synthesis, structures and biological properties. Newer classes of polynuclear organotin-mixed complexes would be developed which may have applications in materials science, catalysis and biological activities.
• Development of mesoporous vanadium phosphates as potential catalysts for selective oxidation of hydrocarbons. A new class of mesoporous vanadium phosphates as potential catalyst for selective oxidation of hydrocarbons would be explored.
• Simultaneous effects of steric congestion and intramolecular secondary interactions on stability and reactivity of diorganotellurides. It is proposed to synthesize new diorganotellurides and study their catalytic activities.
• Design, synthesis, characterization and study of rare earth and transition metal-containing magnetic liquid crystals. The product obtained may find application in magneto-optic data storage devices..
• Sensors for fluoride, calcium and magnesium ions. It is proposed to design and develop efficient chemical sensors for naked eye detection of specific ions.

Research highlights and achievements in the ongoing projects are as follows:

• Three new and efficient methods have been developed for the synthesis of meso free corroles.
• Innovative ligands have been designed for selective fluoride sensing with possible application in analytical chemistry.
• Various non bonded reactions have been studied for developing different nano structure and shape.
• An improved catalytic and environmentally benign process has been developed for the preparation of epoxides from alkenes.
• New synthetic routes have been developed for ?- aminophosphonates and ?-aminophosphonic acids which have biological applications.
• It has been observed for the first time that carbaphosphazenes could be used as reagents in organic transformations in reactions like conversion of alcohols to aldehydes etc.
• New glutathione peroxidase mimics with Se…O , have been discovered.
• Some new compounds have been synthesized, which may act as potential heterogenous catalysts in oxidation reaction.

Physical Chemistry

New projects sanctioned are:

• Study of molecular magnetic properties using coupled-cluster method.
• Size and shape controlled mono and bimetallic ( core-shell and alloyed) nanoparticles synthesis for sensing organic and important biomolecules in different organized media.
• Application of heteronuclear polarization transferred multiple quantum spectroscopy to oriented systems using three dimensional NMR.
• Modeling of non-linear reaction-diffusion processes at modified electrodes.
• Theoretical investigations of adsorption of additives onto the crystal surface of sodium chloride and on other alkyl halides.
• Physicochemical studies in pulmonary surfactants and other amphiphiles with reference to their interfacial mutual interaction and coacervate formation.
• Computer simulation studies of room temperature ionic liquids.
• Design of nanosized ceria based multicomponent oxides for catalytic applications.
• Studies on superamolecular polymers and their blends.
• Investigation of the characteristics of the biologically active systems using the probes showing proton transfer and electron transfer behaviour.
• Selective electrocatalysts for mixed reactant direct methanol fuel cell.
• Solvation within multicomponent solvent systems containing environmentally-benign room temperature ionic liquids.
• Electronic and vibrational spectroscopic investigations of C-H-H-B dihydrogen-bonded clusters and their reactions in gas phase.

Research highlights and achievements in the ongoing projects are as follows:

• New sandwiched composite electrodes, pp_y and CoFe₂O₄ and, pp_y and La_1-x Sr_x MnO₃ have been prepared which are many times more active than a non-composite electrode of the respective oxide for electrochemical reduction of O₂. These new electrodes can be used in a much wider pH range ( pH>4) without deterioration.
• It has been found for the first time that for a three state Born-Oppernheimer (BO) coupling the effect is equivalent to a potential due to elliptic motion of the nuclei around the CI.
• Sulphonic acid functionalized poly(vinyl alcohol)-silica nanocomposite membranes have been prepared. These membranes with high water uptake, moderate ion-exchange capacity (IEC) values, good ionic conductivity and permselectivity with no significant effect on thermal and mechanical stability, offer a new dimension for the preparation of organic-inorganic hybrid membranes. These membranes will be suitable for fuel cell and chlor-alkali applications as a substitute for the Nafion membrane.
• Gold nano-particle has been made and it is found to be extremely stable and resistant to agglomeration and precipitation for a considerable period of time.
• Controlled synthesis of the important hydrophobic polymer, poly (methyl methacrylate), in the environment friendly solvent aqueous ethanol at ambient temperature has been reported for the first time.
• Different electrodes have been prepared for destruction of phenols and its derivatives. The destruction of phenol derivatives in acetone -water mixed media showed the feasibility of even water -insoluble species to be oxidized electrochemically. The disc shaped nickel electrode modified by Sol-Gel method has been developed for the first time.
• In a project on layered double hydroxide, it has been concluded that non-uniform broadening of lines in the Powder X-ray diffraction patterns of layered materials arises due to structural disorder and not due to particle size effects. It has been shown that the required kind of disorder could be engineered into a layered hydroxide by increasing the pH at precipitation.
• It has been demonstrated that the low frequency hydrogen bond vibrations are mixed with the intramolecular vibrations of the dimeric moieties and such mode mixing dramatically influence the dynamics of energy relaxation process. It has also been demonstrated using centrosymmetric and non-centrosymmetric dimeric combinations that in the former category of systems the degeneracies of in-phase and out-of-phase vibrational combinations are lifted because of involvement of hydrogen bonds. These observations would be having great significances in analyzing the vibrational spectra of polymeric systems that have repeating units.

Green Chemistry Programme

In order to create awareness in the area of Green Chemistry, two National Workshops were organized at Madurai Kamraj University, Madurai and Nirma University, Ahmedabad. The following projects were funded which also have industrial collaboration:

• Improved process based on membrane for the recovery of acid and organic compounds from reaction mixture. This would help in recovery of valuable chemical products under highly pure condition from different industrial process streams and also its further reuse.
• Production of biosurfactants from genetically engineered Pseudomonas aeruginosa. Molecular biology techniques would be used to overproduce rhamnolipid biosurfactants (which are extensively used in industries) from Pseudomonas sp.
• Development of an integrated and environment friendly saccharification process for enhanced ethanol yield from rice straw. The process would be more energy and chemical efficient in comparison to the existing methods. The product could be used as a biofuel
• Study on the characterization and utilization of waste plastics-Green Technology. It is planned to blend the waste plastics with bitumen, plastic coated aggregate etc. and study its use for material in road construction.