Research Assistant Professor
Dr Kole received B.Sc (Honours) in Chemistry from University of Calcutta (2005), M.Sc in Chemistry from Indian Institute of Technology Madras, Chennai (2007) and Ph.D in Chemistry from National University of Singapore (2012) under supervision of Prof. Jagadese J Vittal. His doctoral thesis title was “Crystal Engineering Studies on the Molecular Salts and Silver(I) Coordination Compounds for [2 + 2] Cycloaddition Reaction in the Solid State”. He continued research at Prof. Vittal’s lab as Postdoctoral Research Associate for more than a year and then joined Institute for Materials Research and Engineering in Singapore as a Scientist. He then moved to Bhabha Atomic Research Centre in Mumbai and worked there as a Scientist before joining SRM University as Research Assistant Professor in Dec, 2016. He was recipient of the prestigious Alexander von Humboldt fellowship for postdoctoral researcher and worked at Julius-Maximilians Universität Würzburg, Germany, for more than three years (Aug, 2017 – Oct, 2020). His research articles have been published in various reputed, high impact journals including Angewandte Chemie, Chemical Communications, Organic Letters, Chemistry – A European Journal, Chemical Society Reviews etc and his current h-index is 14.
Research Interests: Crystal Engineering, Inorganic Chemistry, Organic Chemistry
Research Keywords: Chromophores, Co-crystals and Organic Salts, Coordination Polymers, Metal Organic Frameworks (MOFs), [2 + 2] Cycloaddition Reaction of C=C in the Solid State, Solid State Structural Transformation of Organic and Inorganic Materials, Photophysical Properties, Structure Property Correlation.
Selected Recent Publications
Awards and Recognitions
Crystal Engineering Studies on C=C, C=N and N=N bonds for Solid State Photoreactivity and Structural Transformation
The main objective of crystal engineering is to align the organic or inorganic molecules in preferred orientation in the solids by exploiting weak intermolecular interactions so that the desired physical and chemical properties can be achieved. Since last two decades, the functional olefins containing C=C bonds have been extensively studied to anchor their solid state photoreactivity in co-crystals, organic salts and metal-organic compounds. However, the olefins containing C=N bonds have not been extensively studied so far because of the unstability of C2N2 ring which decomposes to release N2 gas (see Scheme below). This problem can be solved by aligning the olefins in head-to-tail manner where the C and N atoms reside diagonally opposite to each other and thereby stabilising the resulting C2N2 ring. Therefore, in our research, the functional olefins and the templates would be designed in such a way that the C=N bonds of two olefins in their preorganised assemblies stack in head-to-tail manner which can yield a stable C2N2 ring. In addition, studies on reversible formation and thermal cleavage of cyclobutane rings, which is one current interest of the crystal engineering community, would also be explored.
In the case of olefins containing N=N bonds, instead of solid state photoreactivity, stimuli controlled structural transformations and associated physical properties of coordination polymers would be studied. For example, trans-cis isomerization of N=N bonds under exposure to UV light can lead to enhanced adsorption properties in porous coordination polymers and also their varied emission characteristic can be very interesting.
Organic Chromophores and their Applications
Polycyclic aromatic hydrocarbons (PAH), such as pyrene and anthracene, are well-known chromophores for their spectacular photophysical properties. These possess some unique properties, such as intense blue emission, a high fluorescence quantum yield, a long-lived singlet state, and propensity for excimer and exciplex formation. In addition to its rich photophysical properties, pyrene is chemically stable and can enhance intermolecular charge mobility. Many pyrene and anthracene derivatives have, therefore, been developed for a wide range of applications in modern scientific fields which include organic optoelectronic devices, such as organic light emitting diodes (OLEDs), organic field-effect transistors (OFETs), photovoltaic cells (OPVs), and signalling of biomolecules, such as, detection of DNA/RNA interactions. Functionalization of pyrene with pyridyl group and subsequent methylation yielded A-π-A or A-π conjugated dyes, which show significant bathochromic shifts in their emission, which often falls in the “tissue optical window (650 – 1100 nm)” and find applications in various biological studies including their interaction with ds-DNA. They also exhibit rich electrochemistry of viologens.
Coordination Polymers and Metal Organic Frameworks
Metal organic frameworks aka MOFs constitute an important class of materials developed in the last decade. MOFs (also Porous Coordination Polymers, PCPs) possess three dimensional framework structures with large voids, which in turn can be exploited for various applications including gas adsorption, separation, catalysis, drug delivery, chemical sensing etc. Developing a MOF based material includes two steps – designed synthesis and structural characterization of the MOF and secondly, exploiting its void space for a specific application. Metal ions are limited; organic ligands are infinite. By judiciously tuning the combination of organic ligands (generally with carboxylate functionality) and metal ions, numerous numbers of new MOFs can be developed.
Our primary focus is on design and synthesis of novel ligands via suitable catalytic reactions, design and synthesis of lanthanide-based discrete or cluster or polymeric metal organic compounds, spectroscopic and crystallographic characterization of the synthesized compounds, exploration and measurements of various materials properties, e.g. luminescence and magnetic properties and their interdependence. The luminescence in lanthanide-based materials exhibit exceptional features with narrow band-width, long lived emission, ligand induced large Stokes shift and generally high quantum yield. These include a wide range of emissive phenomena e.g. linker-based emission, metal-based emission, ligand-to-metal / metal-to-ligand charge transfer, guest emission, sensitization or antenna effect and so on.
27. G. K. Kole, J. Merz, A. Amar, B. Fontaine, A. Boucekkine, J. Nitsch, S. Lorenzen, A. Friedrich, I. Krummenacher, M. Košćak, H. Braunschweig, I. Piantanida, J.-F. Halet, K. Müller-Buschbaum, T. B. Marder, “2- and 2,7-Substituted para-N-Methylpyridinium Pyrenes: Syntheses, Molecular and Electronic Structures, Photophysical, Electrochemical, and Spectroelectrochemical Properties and Binding to ds-DNA”, Chemistry – A European Journal, 2020, just accepted; DOI: 10.1002/chem.202004748. I. F. 4.85.
26. B. B. Rath, G. K. Kole, S. A. Morris, J. J. Vittal “Rotation of a helical coordination polymer by mechanical grinding”, Chemical Communications, 2020, 56 (46), 6289-6292. DOI: 10.1039/D0CC02158J. I. F. 6.164
25. Q. Lu, G. K. Kole, A. Friedrich, K. Müller-Buschbaum, Z. Liu, X. Yu, T. B. Marder, “Comparison Study of the Site-Effect on Regioisomeric Pyridyl–Pyrene Conjugates: Synthesis, Structures, and Photophysical Properties”, The Journal of Organic Chemistry, 2020, 85 (6), 4256-4266. DOI: 10.1021/acs.joc.9b03421. I.F. 4.745
24. A. Tyagi, G. K. Kole, A. Y. Shah, A. Wadawale, A. P. Srivastava, M. Kumar, G. Kedarnath, V. K. Jain, “Accessing copper-tin-sulfide nanostructures from diorganotin(IV) and copper(I) 2-pyrazinyl thiolates” Journal of Organometallic Chemistry, 2019, 887, 24-31. DOI: 10.1016/j.jorganchem.2019.02.026. I. F. 2.066
23. B. B. Rath, G. K. Kole, J. J. Vittal, “Structural Transformation of Photoreactive Helical Coordination Polymers to Two-Dimensional Structures”, Crystal Growth and Design, 2018, 18 (10), 6221-6226. DOI: 10.1021/acs.cgd.8b01087. I. F. 4.153
22. G. K. Kole, M. Kumar, “Patterns of hydrogen bonding involving thiourea in the series of thiourea⋅ trans-1, 2-bispyridyl ethylene cocrystals–A comparative study”, Journal of Molecular Structure, 2018, 1163, 18-21. DOI: 10.1016/j.molstruc.2018.02.092. I. F. 2.12
21. G. K. Kole, U. Sambasivam, G. K. Tan and J. J. Vittal, “Making Photoreactive trans-3′(n′-Pyridyl)acrylic Acid (n= 2, 3) with Head-to-Tail Orientation in the Solid State by Salt Formation” Crystal Growth and Design, 2017, 17 (5), 2694-2699. DOI: 10.1021/acs.cgd.7b00192. I. F. 4.153
20. G. K. Kole, A. P. Wadawale, S. Nigam, C. Majumder and V. K. Jain, “Intermolecular Aurophilic versus Intramolecular Au···N Secondary Interactions in Two-Coordinate Gold(I) Selenolate Complexes” ChemistrySelect, 2016, 1, 4131-4136, DOI: 10.1002/slct.201601122
19. G. K. Kole, A. Chanthapally, G. K. Tan and J. J. Vittal, “Solid State Packing and Photoreactivity of Alkali Metal Salts of trans,trans-Muconate” Cryst. Growth Des., 2015, 15, 5555-5559. DOI: 10.1021/acs.cgd.5b01213 (Impact factor 4.42).
18. G. K. Kole, T. Kojima, M. Kawano and J. J. Vittal, “Reversible [2+2] Single-Crystal-to-Single-Crystal Photochemical Formation and Thermal Cleavage of a Cyclobutane Ring” Angew. Chem. Int. Ed., 2014, 53, 2143-2146. DOI: 10.1002/anie.201306746 (Impact factor 11.71).
17. G. K. Kole, K. V. Vivekananda, M. Kumar, R. Ganguly, S. Dey and V. K. Jain, “Hemilabile silver(I) complexes containing pyridyl chalcogenolate (S, Se) ligands and their utility as molecular precursors for silver chalcogenides” CrystEngComm, 2015, 17, 4367-4376. DOI: 10.1039/c5ce00626k (Impact factor 3.83).
16. G. K. Kole, K. V. Vivekananda, M. Kumar, S. Dey and V. K. Jain, ‘Silver(I) coordination polymer of 4,4'-dipyridyl selenide and its Solvothermolysis” Int. J. Chem., 2014, 3, 263-268.
15. G. K. Kole, R. Medishetty, L. L. Koh and J. J. Vittal, “Influence of C-H···π interaction on the solid–state [2+2] cycloaddition reaction of a Ag(I) coordination complex in an inorganic co-crystal” Chem. Commun., 2013, 49, 6298-6300. DOI: 10.1039/C3CC42793E (Impact factor 6.83).
14. G. K. Kole, A. M. P. Peedikakkal, B. M. F. Toh and J. J. Vittal, “Solid-State Structural Transformations and Photoreactivity of 1D-Ladder Coordination Polymers of PbII” Chem. Eur. J., 2013, 19, 3962-3968. DOI: 10.1002/chem.201203678 (Impact factor 5.77).
13. A. Chanthapally, G. K. Kole, K. Qian, G. K. Tan, S. Gao and J. J. Vittal, “Thermal cleavage of cyclobutane rings in the photodimerized coordination polymeric sheets” Chem. Eur. J., 2012, 18, 7869-7877. DOI: 10.1002/chem.201103791 (Impact factor 5.77).
12. G. K. Kole, and J. J. Vittal, “Solid state reactivity and structural transformations involving coordination polymers” Chem. Soc. Rev., 2013, 42, 1755-1775. DOI: 10.1039/C2CS35234F (Impact factor 34.09; a part of the centenary issue to celebrate the Nobel Prize in Chemistry awarded to Alfred Werner).
11. G. K. Kole, C. K. Chin, G. K. Tan and J. J. Vittal, “Silver(I) macrocycles and coordination polymers containing pyridyl carboxylate and phosphine ligands” Polyhedron, 2013, 52, 1140-1448. DOI: 10.1016/j.poly.2012.04.003 (Impact factor 2.11; a part of the Werner 2013 Special Issue).
10. G. K. Kole, G. K. Tan and J. J. Vittal, “Solid state photodimerization of trans-2-(4-pyridyl)-4-vinylbenzoic acid via salt formation and isomerisation of cyclobutane compounds in solution” CrystEngComm, 2012, 14, 7438-7443. DOI: 10.1039/c2ce26086g (Impact factor 3.83).
9. G. K. Kole, G. K. Tan, L. L. Koh and J. J. Vittal, “Co-crystals of tetrakis-1,2,3,4-(4'-carboxyphenyl)cyclobutane with dipyridyl spacers: design and serendipity” CrystEngComm, 2012, 14, 6190-6195. DOI: 10.1039/c2ce25513h (Impact factor 3.83).
8. G. K. Kole, G. K. Tan and J. J. Vittal, “Photoreactivity of Ag(I) Complexes and Coordination Polymers of Pyridyl Acryclic Acids” Cryst. Growth Des., 2012, 12, 326-332. DOI: 10.1021/cg201119c (Impact factor 4.42).
7. M. H. Mir, J. X. Ong, G. K. Kole, G. K. Tan, M. J. McGlinchey, Y. Wu and J. J. Vittal “Photoreactive gold(I) macrocycles with diphosphine and trans, trans-muconate ligands” Chem. Commun., 2011, 47, 11633-11635. DOI: 10.1039/c1cc14442a (Impact factor 6.83).
6. R. Medishetty, L. L. Koh, G. K. Kole and J. J. Vittal, “Solid state structural transformation from 2D-interdigitated layer to 3D-interpenetrated structure” Angew. Chem. Int. Ed., 2011, 50, 10949-10952. DOI: 10.1002/anie.201104106 (Impact factor 11.71).
5. G. K. Kole, G. K. Tan and J. J. Vittal, “Role of anions in the synthesis of cyclobutane derivatives via [2 + 2] cycloaddition reaction in the solid state and their isomerization in solution” J. Org. Chem., 2011, 76, 7860-7865. DOI: 10.1021/jo201268p (Impact factor 4.72).
4. G. K. Kole, G. K. Tan and J. J. Vittal, “Crystal engineering studies on the salts of trans-4,4'-stilbenedicarboxylic acid in the context of solid state [2+2] cycloaddition reaction” CrystEngComm, 2011, 13, 3138-3145. DOI: 10.1039/c0ce00224k (Impact factor 3.83).
3. G. K. Kole, A. J. Cairns, M. Eddaoudi and J. J. Vittal, “Solvent-free porous framework resulted from 3D entanglement of 1D zigzag coordination polymer” New J. Chem., 2010, 34, 2392-2395. DOI: 10.1039/c0nj00217h (Impact factor 3.09; a part of the themed issue on coordination polymer: structure and function).
2. G. K. Kole, L. L. Koh, S. Y. Lee, S. S. Lee and J. J. Vittal, “A new ligand for metal–organic framework and co-crystal synthesis: mechanochemical route to rctt-1,2,3,4-tetrakis-(4'-carboxyphenyl)-cyclobutane” Chem. Commun., 2010, 46, 3660-3662. DOI: 10.1039/c0cc00012d (Impact factor 6.83).
1. G. K. Kole, G. K. Tan and J. J. Vittal, “Anion-controlled stereoselective synthesis of cyclobutane derivatives by solid state [2+2] cycloaddition reaction of the salts of trans-3-(4'-pyridyl) acrylic acid” Org. Lett., 2010, 12, 128-131. DOI: 10.1021/ol9025233 (Impact factor 6.36)