A couple of Ph.D. positions (Chemistry) are available in the research group

Dr. Pintu Kumar Kundu

Affiliation

Assistant Professor (UGC)

Institute of Chemical Technology, Mumbai

Mumbai – 400019

Email: pk.kundu@ictmumbai.edu.in

Office: F206, 1st Floor, Department of Oils, Oleochemicals and Surfactants Technology

---------------------------------------------------------------------------------------------------------------

Past Experiences

Assistant Professor, SRM University (2 Years)

Post-Doctoral Experiences

Weizmann Institute of Science, Israel (3 Years)

Indian Institute of Technology, Bombay (1 Year)

Selected Research Highlights

Azobenzene-attached (NHC)Gold(I) and (NHC)Copper(I) Complexes as Photoswitchable Catalysts Link

Chem. Eur. J. 2024, 30, e202402381

Azobenzene-attached N-heterocyclic carbene (NHC) complexes of coinage metals were synthesized to demonstrate the effect of light-induced stereoelectronic changes in fine-tuning the rates of organic transformations. Two photoswitchable catalysts (pre-catalysts), namely, N,N'-bis-azobenzene-based (NHC)gold(I) complex that enables a four-fold decrement of the rate of oxazoline formation reaction upon trans to cis isomerization of the attached photoswitchable moieties, and N,N'-bis-azobenzene-derived (NHC)copper(I) complex that alters the rate of azide-alkyne cycloaddition reaction, were reported. The photomodulation of catalysts was used to toggle the reaction rate using UV and blue light exposure.

Light-controlled self-assembly of non-photoresponsive nanoparticles Link

Nature Chem. 2015, 7, 646-652

Organic molecular switches namely, protonated-merocyanine was shown to modify the pH of a methanolic medium reversibly when exposed to visible light on or off - in such a way that the nanoparticles, which do not respond to external stimuli such as light, undergo self-assemble / deassemble process in a reversible fashion depending on the state of the external switch. Performing the assembly process in thin films of gels allowed us to draw images that spontaneously disappeared after a specific period of time.

Nanoporous frameworks exhibiting multiple stimuli responsiveness Link

Nature Commun. 2014, 5, 3588

Majority of organic molecular switches require conformational freedom to isomerize, and therefore, switching in the solid state is prohibited. Here we describe two families of nanoporous materials incorporating the spiropyran molecular switch. These materials exhibit a variety of interesting properties, including reversible photo-chromism and acidochromism, light-controlled capture and release of metal ions, as well reversible chromism induced by solvation/desolvation.

Cyclic kinetics during thermal equilibration of an axially chiral bis-spiropyran Link

J. Am. Chem. Soc. 2014, 136, 11276–11279

A compound combining the features of a molecular rotor and a photoswitch was synthesized and was shown to exist as three diastereomers, which interconvert via a reversible cyclic reaction scheme. Each of the three diastereomers was isolated, and by following the equilibration kinetics, activation barriers for all reaction were calculated. The results indicate that the properties of molecular switches depend heavily on their immediate chemical environment. The conclusions are important in the context of designing new switchable molecules and materials.

Azobenzene isomerization-induced photomodulation of electronic properties of N-heterocyclic carbenes Link

Chem. Eur. J. 2020, 26, 4214–4219

Azobenzene-based protonated N-heterocyclic carbenes (NHCs), N,N'- bis(azobenzene)imidazolium chlorides (IAz-X.HCl), were successfully synthesized, and switching abilities of the attached azobenzene units, along with the concomitant photoinduced generation of geometric isomers, were studied. The extent of photomodulation of electronic properties in the NHC’s-ring of the p-methoxy-azobenzene derivative is determined via the Tolman Electronic Parameter (TEP). This fine phototuning of electron-donating ability at the catalytic center would pave the way to control NHC-/NHC-metal catalyzed organic transformations via external stimuli.

Research Interests

Organic photochromism, acidochromism, stimuli-responsiveness
Azobenzene and spiropyran-based smart/functional molecules and materials
Photoswitchable surfactants and light-induced modification of surface activities.
Photoswitchable catalysis
Multifunctional dynamic materials
Organic molecular switches
Synthetic organic chemistry