Thimmaiah Govindaraju

Bio: Thimmaiah Govindaraju is an academic researcher from Jawaharlal Nehru Centre for Advanced Scientific Research. The author has contributed to research in topics: Medicine & DNA. The author has an hindex of 43, co-authored 136 publications receiving 5341 citations. Previous affiliations of Thimmaiah Govindaraju include University of Wisconsin-Madison & National Chemical Laboratory.

Aldazine-based colorimetric sensors for Cu2+ and Fe3+

Abstract: We have developed novel aldazine-based colorimetric chemosensors for Cu 2+ and Fe 3+ . The aldazine ligands were synthesized by simple condensation of 4-diethylamino-salicylaldehyde and 8-hydroxyjulolidinal with hydrazine. The (4-diethylamino)-salicylaldehyde-azine ( SA ) showed high selectivity and sensitivity towards Cu 2+ over the other alkali and transition metal ions. In the presence of Cu 2+ , absorption band of SA at 425 nm red shifted to 545 nm. The color of solution changed from pale yellow to purple color. Interestingly, 8-hydroxyjulolidinal-azine ( JA ) showed selectivity towards Fe 3+ over alkali and transition metal ions. In the presence of Fe 3+ , the color of the ligand solution changed from pale yellow to violet. The absorption band of JA at 445 red shifted to 575 nm. The fluorescence of ligands SA and JA was completely quenched in the presence of Cu 2+ and Fe 3+ , respectively. However, the quenched fluorescence of JA –Fe 3+ complex can be reversibly restored using cysteine.

Conformationally constrained (coumarin-triazolyl-bipyridyl) click fluoroionophore as a selective Al3+ sensor.

Abstract: A conformationally constrained (coumarin−pyrrolidinyl−triazolyl−bipyridyl) fluoroionophore conjugate was synthesized through click chemistry. The fluoroionophore serves as a selective chemosensor for Al3+ based on internal charge transfer. The coumarin−bipyridyl chemosensor exhibited a high association constant with submicromolar detection for the aluminum ion.

Functionalization of Graphene: Covalent and Non-Covalent Approaches, Derivatives and Applications

Abstract: Approaches, Derivatives and Applications Vasilios Georgakilas,† Michal Otyepka,‡ Athanasios B. Bourlinos,‡ Vimlesh Chandra, Namdong Kim, K. Christian Kemp, Pavel Hobza,‡,§,⊥ Radek Zboril,*,‡ and Kwang S. Kim* †Institute of Materials Science, NCSR “Demokritos”, Ag. Paraskevi Attikis, 15310 Athens, Greece ‡Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacky University Olomouc, 17. listopadu 12, 771 46 Olomouc, Czech Republic Center for Superfunctional Materials, Department of Chemistry, Pohang University of Science and Technology, San 31, Hyojadong, Namgu, Pohang 790-784, Korea Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, v.v.i., Flemingovo naḿ. 2, 166 10 Prague 6, Czech Republic

Molecular self-assembly and nanochemistry: A chemical strategy for the synthesis of nanostructures

Abstract: Molecular self-assembly is the spontaneous association of molecules under equilibrium conditions into stable, structurally well-defined aggregates joined by noncovalent bonds. Molecular self-assembly is ubiquitous in biological systems and underlies the formation of a wide variety of complex biological structures. Understanding self-assembly and the associated noncovalent interactions that connect complementary interacting molecular surfaces in biological aggregates is a central concern in structural biochemistry. Self-assembly is also emerging as a new strategy in chemical synthesis, with the potential of generating nonbiological structures with dimensions of 1 to 10(2) nanometers (with molecular weights of 10(4) to 10(10) daltons). Structures in the upper part of this range of sizes are presently inaccessible through chemical synthesis, and the ability to prepare them would open a route to structures comparable in size (and perhaps complementary in function) to those that can be prepared by microlithography and other techniques of microfabrication.