Highlights from Kaleidoscope: A Discussion Meeting in Chemistry, Goa, India, July 2016

Abstract

“Kaleidoscope: A Discussion Meeting in Chemistry” is an annual gathering of young Indian investigators working in various fields of chemistry and allied areas. The meeting serves as a common ground to cross-pollinate new research ideas and come up with coherent approaches to solve long-standing and challenging problems within an informal setting. The third installment of the meeting was hosted within the serene confines of the International Center, Goa, India from July 14th–17th 2016. In this report, we provide an overview of the topics covered and the ensuing discussions which took place during Kaleidoscope-2016 in order to highlight the scientific rigour of the meeting.

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Introduction to the Kaleidoscope concept

The Kaleidoscope meeting series was initiated in 2014 by Professor Naresh Patwari with support from the chemistry faculty members at IIT Bombay. Prof. Patwari's original concept was to bring together early career chemists in India through a common platform which promoted uninhibited discussion on research goals, scientific problems, and associated professional challenges. The meeting has since become an established feature in the community known for the rigorous discussions during the scientific presentations. The meeting has also proven beneficial for participants in terms of spawning active collaborations. Meeting participation is by invitation-only with a special emphasis on including young investigators. Kaleidoscope meetings emphasize poster presentations in a prespecified format from all participants with posters on display for the duration of the meeting. Participants also present their poster in the form of a conventional PowerPoint presentation. The meeting format also allows ample time for one-on-one and group discussions. The poster/platform presentations are required to provide equal emphasis on current research activities, to showcase unpublished results, and the future outlook of the research group.

The Kaleidoscope-2016 meeting (July 15–17 2016) was attended by 27 participants (Fig. 1) and featured a total of 9 thematic platform sessions covering all areas of chemistry. Sessions were thematic and chaired by a discussion leader who provided a 15 minute overview on the session topic highlighting key challenges and linking them to the presentations in the session. The oral presentations were interspersed with questions and discussions. In addition, each day concluded with a round table discussion featuring all participants, where discussion leaders re-visited key questions and points raised during the presentations and moderated the subsequent discussion. Discussions included blackboard explanations of concepts and technical clarifications. The round table discussion was recorded by the conference organizers with the help of post-conference inputs from participants.

Fig. 1 Group picture of all the participants in the Kaleidoscope 2016 meeting held at the International Center, Goa. From left to right (Top row): Vaibhav Prabhudesai, Akash Gulyani, Prashant Singh, Roop Mallik, Jyotishman Dasgupta, Deeksha Gupta, Ankona Datta, Shachi Gosavi, Neetu Singh, Kaushik Chatterjee, Janardan Kundu, Biman Jana, Kanishka Biswas, Ravi P. Singh, Harinath Chakrapani and Anindya Dutta. (Bottom row): Abhishek Dey, Janardhan Kundu, Sabuj Kumar Kundu, Amit Paul, Prasenjit Mal, Sayan Bagchi, Naresh Patwari, Rajarshi Chakrabarti, Ravindra Venkatramani and Kana Sureshan.

On the eve of the meeting, the program schedule was revealed by the organizers wherein participants were informed about the speaking slots and discussion leaders were assigned. This unique arrangement ensured that the participants had to plan for attending all the days of the meeting. Below we provide a summary of each thematic session and excerpts of the discussions that followed.

Session-I (Day 1): Dynamics in complex systems

The first session on July 15th was chaired by Shachi Gosavi from NCBS, Bangalore. She provided an overview of insights provided by multi-scale computational techniques on the dynamics of systems ranging from small molecules to macromolecular structures like proteins. The session included three talks. First, Rajarshi Chakrabarti from IIT Bombay discussed tracer diffusion dynamics through polymer media. He discussed multiple regimes of tracer diffusion dynamics which are dependent on polymer concentration. The discussions focused on understanding the assumptions and limiting behavior of the model, differentiating between diffusion controlled dynamics and that under polymer crowding, and extracting tracer dwell times. Suman Chakraborty from NCL, Pune discussed long-range water mediated interactions, electrostatics and dynamics in lipid vesicle models. Discussions covered issues such as the definition of water orientations at the center of spherically symmetrical lipid vesicles, differentiating between the effects arising from membrane fluctuation dynamics versus those induced by the electrostatics, reconciling/connecting simulations with experiments which report on hydrogen bonding strength of water in bulk and at interfaces. Ravi Venkatramani from TIFR, Mumbai presented computational evidence for charge transfer (CT) transitions arising from charged amino acids in the absorption profile of proteins beyond 300 nm. Discussions covered the dependence of the CT absorption spectral features on counter-ion concentration and environmental effects, the mechanism of photoinduced CT, the sensitivity of the spectral signature to different charged amino acids, suggestions for building experimental models to test the theoretical predictions, and exciton couplings for the charge transfer band. A transcript of the round-table discussions for the session is included in the (ESI†) (Day 1 – Session I).

Session-II (Day 1): Chemical interactions

The second session on July 15th was chaired by Naresh Patwari from IIT-Bombay, Mumbai, who highlighted the diversity of chemical bonding interactions and their ramifications for both biological and synthetic applications. He emphasized the need to systematically probe weak interactions through experimental and theoretical studies. Prashant C. Singh from IACS Kolkata spoke on the photophysics and solvation behavior of fluorinated molecules at lipid-solvent interfaces. Discussions covered the probing of water orientations at interfaces using Sum Frequency Generation (SFG) techniques used by the speaker, the correlation between ground state observables with the excited state dynamics, and connecting the experiments with the computational studies of Suman Chakraborty (Session-I). Naresh Patwari from IIT-Bombay presented a talk on the role of electrostatics in intermolecular interactions within crystalline settings. Discussions covered the extent of C–F bond polarizability relative to that of the C–H bond and the dependence of bond polarizability on the nature of the carbon. Sayan Bagchi from NCL, Pune presented studies on spectroscopic probes of carbonyl species, dynamics and associated applications. Discussions examined the physical basis for correlations between vibrational IR frequency shifts and NMR chemical shifts presented by the speaker, and variances for the experimental and theoretical data (chemical shifts, IR frequencies, electric fields).

Session-III (Day 1): Biomaterials and metabolism

The third session of Kaleidoscope 2016 was chaired by Ankona Datta from TIFR, Mumbai. She highlighted the challenges in developing bio-materials for targeted delivery of therapeutic agents and also as structural entities for tissue regeneration. An important consideration in biomaterial design is the ultimate fate of the material in biological systems. In this context, material uptake and cellular cargo transport pathways were discussed. Kaushik Chatterjee from IISc Bangalore presented various material-based strategies that are being developed in his group to prevent bacterial infections associated with medical implants and devices. He discussed the use of nano-patterns to mechanically disrupt bacterial growth in implants, controlled release of drugs from materials and applications of surface functionalized nanoparticles embedded in polymer matrices. The effect of nanopatterning in implant material elicited discussions about the relationship between surface topology and anti-bacterial activity of the materials and the ability of the surface to distinguish between human and bacterial cells. The second talk, given by Neetu Singh from IIT Delhi, highlighted the use of cubosomes which are materials containing two distinct hydrophilic regions separated by a bilayer. Neetu discussed several parameters that could be optimized in these materials for controlled drug delivery. Finally, Roop Mallik from TIFR, Mumbai discussed the role of motor proteins in cargo transport within cells and proposed that micro-domains of cholesterol might have a regulatory effect on motor protein activity. On the whole, this diverse session on bio-materials included scientists from both materials and biophysics backgrounds and detailed discussions on both material development and the fate of artificial materials in biological systems ensued. A transcript of the round-table discussions for the session is included in the (ESI†) (Day 1 – Session III).

Session-IV (Day 2): Tools for probing biology

The fourth session of Kaleidoscope-2016 was chaired by Kana Sureshan from IISER, Thiruvananthapuram. Synthetic chemical probes have played a critical role in both elucidating biological mechanisms and in guiding therapeutic routes for diseases. Sureshan highlighted challenges in developing sensors and probes for tracking bio-molecules ranging from proteins to signalling lipids, and for elucidating the role of transient redox active species in cells. Akash Gulyani from INSTEM, Bangalore presented strategies for developing protein-based biosensors for elucidating cell-signaling pathways. He also discussed ways of using optical probes and imaging to understand cell migration and tissue re-modeling in emerging models of tissue regeneration including hydra and planaria. Ankona Datta from TIFR, Mumbai highlighted challenges in tracking the spatiotemporal dynamics of signal-mediating phospholipids in live biological systems in the context of elucidating phospholipid mediated cell-signalling pathways. She presented her group's work on developing ratiometric cell-permeable sensors for imaging a major class of signal mediating phospholipid, the phosphoinositides. Detailed discussion on the design of peptide-based sensors, interaction of phosphoinositide binding domains to phospholipid headgroups and the mechanism of membrane permeability of the probes followed the presentation. Harinath Chakrapani from IISER Pune discussed strategies for utilizing the differences in cellular response to redox stress to develop anti-bacterial agents against multi-drug resistant bacterial strains. He presented his group's work on utilizing natural-product scaffolds as starting points for designing molecules that can disrupt redox homeostasis in bacteria. He went on to highlight possible mechanisms by which the designed molecules can selectively enhance reactive oxygen species production in bacteria. Extensive discussions on the mechanism of antibiotic resistance and the mode by which the designed molecules might selectively cause oxidative stress in bacteria while sparing human cells followed the presentation. Overall this session highlighted diverse chemical biology approaches for tracking and manipulating biological systems toward mechanistic understanding and therapeutic intervention. A transcript of the round-table discussions for the session is included in the (ESI†) (Day 2 – Session IV).

Session-V (Day 2): Materials for energy conversion

Chemists have a big role to play in designing new materials to satisfy the contemporary energy needs of society. Ravi Venkatramani from TIFR, Mumbai, while chairing this session, called for specific routes to rationally design materials. He outlined a combined need to discover materials for energy generation and storage with involvement from researchers across multiple disciplines. Amit Paul from IISER Bhopal talked about water oxidation by heterogeneous electrocatalysts. He showed that iron oxyhydroxide thin films can act as efficient water oxidation catalysts. In addition he also showed how metal phosphonate nanocages can be used for water oxidation at different pH values. There were questions on spectroscopic methods to probe the nature of reaction intermediates as well as discussion on the correlation between reaction rates and pore size. Kanishka Biswas from JNCASR Bangalore talked about his group's efforts to fabricate efficient thermoelectric materials from complex chalcogenides. He explained the origin of the efficiency factor ZT while describing how optimizing both electrical and thermal conductivity is important for thermoelectrics. Discussions ranged from the fundamentals of making such thermoelectric materials to questions on how anharmonic rattling of elemental lone pairs affects thermal conductivity. Abhishek Dey from IACS, Kolkata concluded the session by demonstrating the universal catalytic behavior of porphyrin-based molecular electrocatalysts synthesized in his group. He showed convincingly that rational catalyst designs for H⁺, CO₂, and NO reduction shared striking similarities in terms of active site elements with slightly changed electronics. Questions ranged from the molecular nature of the active catalyst to possibilities of CO reduction. In addition there was a discussion on CO₂ reduction pathways to generate C solid and O₂ gas. The idea of confining reactive intermediates was highlighted.

Session-VI (Day 2): Excited states

Sayan Bagchi from NCL, Pune chaired this session focussed on exciting molecules with light and high energy electrons. He provided an overview of how excited states are experimentally probed and computationally verified. He highlighted the accessibility of excited molecular states through experiments such as electron impact spectroscopy. In line with this theme, Vaibhav Prabhudesai from TIFR, Mumbai spoke about his group's efforts to understand chemical reactivity through the specific example of electron attachment studies on ozone. He described a velocity slice imaging experimental set-up and electron spectroscopy techniques as applied to molecular systems. The attendees discussed how molecular dynamics information was probed by the experiments. Anindya Datta from IIT Bombay discussed his group's recent work on photoexcited state dynamics of Salophen and its complexes with Zn²⁺ and Al³⁺. Anindya pointed out that experiments revealed how previous work had misinterpreted the emission features and purifying the molecule helped his group understand their properties better. Questions ranged from the characterization of the metal complexes and their speciation to discussion on femtosecond up-conversion technique. Jyotishman Dasgupta from TIFR, Mumbai talked about the recent work in his group on tracking exciton dynamics in conjugated polymers using time-resolved Raman spectroscopy. He mentioned the delineation of reaction coordinates using vibrational spectroscopy and also demonstrated the implications of a fundamental understanding of reaction coordinates towards bond selective photochemistry. Questions on how to probe polymer–fullerene interfaces, details of Raman spectra and photochemistry of organic molecules were raised and discussed. A transcript of the round-table discussions for the session is included in the (ESI†) (Day 2 – Session VI).

Session-VII (Day 3): C–H activation and C–C coupling

A thematic session on C–H activation and carbon–carbon bond formation emphasised the diversity of this meeting. Sabuj Kundu from IIT Kanpur highlighted fundamental challenges in carrying out regioselective chemical reactions and functionalization. Specifically, Sabuj showed glimpses of modern methodologies executed by prominent organic chemists around the world especially using directing groups. The scientific session was started by Nidhi Jain, IIT Delhi who talked about palladium and copper in cross-coupling and C–H bond activation. Her focus was to demonstrate her strategies on developing new reactions with both molecular catalysts as well as nanoparticles with ionic liquid capping. Questions about the mechanistic understanding of Pd-nanoparticle catalyzed reactions were raised and rigorous discussion followed on how to characterize intermediates. The second talk was given by Ravi P. Singh from IIT Delhi on selective C–C bond formation reactions leading to synthesis of complex organic molecules. He presented results on cross dehydrogenated coupling reactions which helped in constructing large organic backbones. The talk led to questions about the mechanisms of some of the transformations he presented as well as on the stability of certain reagents. Sabuj Kundu from IIT Kanpur presented his group's work on bi-functional Ru²⁺ complex catalyzed chemoselective transfer hydrogenation and tandem C–C bond formation using alcohols. He showed the use of alcohols as alkylating agents while using a Ru²⁺ catalyst. Discussion were primarily focused on reaction rates of product formation and molecular interactions with the Ru-catalyst. A transcript of the round-table discussions for the session is included in the (ESI†) (Day 3 – Session VII).

Session-VIII (Day 3): Computational biophysics

The second session on July 17th was chaired by Rajarshi Chakraborty from IIT-Bombay, Mumbai. He highlighted the complexity of biological systems and the scope of investigating such systems using atomistic and coarse-grained modelling/simulations. The first speaker of the session, Shachi Gosavi from NCBS, Bangalore, presented computational descriptions of protein dynamics using structure based models (coarse-grained or atomistic models that encode the structure of the biomolecule). She described how such models could uncover mechanisms of ligand recognition. Discussions examined the connection of slow delocalized fluctuations extracted from the models to protein function, and the effect of spectroscopic probes on protein structure and dynamics. In the second talk of the session, Jagannath Mondal from TIFR-TCIS, Hyderabad, presented microsecond atomistic computer simulations of the binding of ligands to a protein active site and coarse-grained models of cavity solvation. Discussions addressed the influence of cavity electrostatics on wetting–dewetting transitions and enhanced sampling protocols to capture rare events and kinetics. Biman Jana from IACS, Kolkata spoke about the mechanism of ice recognition by anti-freeze proteins captured using atomistic simulations. Discussions examined the clathrate model proposed by the speaker as a general mechanism of action for all anti-freeze proteins, physiological concentrations of anti-freeze proteins in the cells of relevant organisms and the validity of MD simulations and associated water models at low temperatures. A transcript of the round-table discussions for the session is included in the (ESI†) (Day 3 – Session VIII).

Session-IX (Day 3): Novel methodologies in synthesis

The final session of Kaleidoscope-2016 was chaired by Nidhi Jain from IIT, Delhi. Nidhi discussed the importance of developing new methods for the synthesis of biologically-relevant small molecules and fine-tuning techniques for designing functional materials. The first talk in the session was presented by Kana Sureshan from IISER, Thiruvananthapuram. Sureshan discussed the synthetic strategies for developing a library of carbasugars with the ultimate goal of identifying glycosylase inhibitors. Prasenjit Mal from NISER, Bhubaneshwar, presented methods to minimize the usage of chemicals in routine chemical synthesis. His group has demonstrated the use of ball-milling methods to reduce the use of solvents in diverse chemical reactions ranging from oxidation and amidation, to halogenation and self-assembly reactions. It was suggested that ball milling methodologies supply mechanical energy to the reaction leading to increased reaction yields at ambient temperature. Prasenjit also discussed his group's efforts toward the development of efficient synthetic protocols using ultrasound and visible light photo-redox mediated catalysis. Discussions regarding whether the product distribution obtained by performing reactions under ball-milling conditions would be similar to the product distribution obtained for reactions performed in solution-phase followed the talk. Finally, Janardan Kundu from NCL, Pune presented the use of galvanic replacement reactions to develop hollow metallic nano-structures for nano-catalysis applications. A polyhedral Cu₂O microparticle-based self-templating strategy is well-known for the synthesis of Cu₂O–M heterostructures (M = Au, Pd, Pt) and Au nano- and mesocages. However, reports on Cu₂O–Ag heterostructures and the ensuing Ag mesocages are scarce. No reports describe the phenomenon of facet selectivity during the galvanic replacement reaction (GRR) based deposition of Ag on Cu₂O template particles. Janardan's group has identified the underlying rationale behind the observed difficulty in nucleating Ag nanoparticles on an octahedral Cu₂O template particle. The group has utilized an appropriately chosen surfactant for the silver precursor and has fabricated Cu₂O–Ag hetero-structures (octahedral, cubic) with controlled loading density of Ag NPs on the Cu₂O surfaces. Discussions on the potential applications of the developed nano-materials in SERS and as nano-catalysts for cross-coupling reactions followed the talk. A transcript of the round-table discussions for the session is included in the ESI† (Day 3 – Session XI).

RSC hosted session

Deeksha Gupta presented a special RSC session which introduced new RSC journals and addressed queries regarding publication strategies. She highlighted strategies for the placement of scientific research with optimum visibility. The session lasted for an hour with many questions and ultimately lead to the proposal for a special web issue covering Kaleidoscope-2016. The organizers, along with Deeksha Gupta, discussed this proposal post-conference and it was agreed that unpublished research presented at Kaleidoscope and submitted to the RSC before December 2016 should be a part of this special issue. The RSC, indeed, published the articles linked to this meeting in a web issue titled “New Frontiers in Indian Research” which can be found at http://pubs.rsc.org/en/journals/articlecollectionlanding?sercode=sc&themeid=880d2173-d694-43db-ad2b-24a92fd89db4.

Poster session and socials

The meeting schedule was planned in such a way that poster sessions followed every thematic session. Poster sessions formed seeding grounds for nurturing new collaborations and furthering the discussions that were triggered by the oral talks. Apart from the poster sessions, informal beer socials were organized during the evening near the poster area. A beach trip was organized on the evening of 15th July, for which all the conference attendees hiked to the beach. The enthusiasm was high despite the light drizzle en route to the beach. After a fun-filled evening which included dinner, the participants got back for a late night round table session to discuss the science presented earlier in the day.

Concluding remarks

The organizers presented concluding remarks on the evening of July 17th. As a primary agenda the organizers asked all the conference attendees whether this meeting should be continued next year. The unanimous answer was YES! The participants expressed great enthusiasm for the format of the meeting and the new round-table discussion that was included in the current meeting. Subsequently, the choice of the next organizing committee was made. Sayan Bagchi (NCL Pune) and Harinath Chakrapani (IISER Pune) expressed their interest in organizing Kaleidoscope 2017 and the entire quorum supported the proposal.

The meeting produced stimulating discussions which have subsequently led to 14 peer-reviewed publications in top-tiered RSC journals. These publications have been highlighted in a special web-issue covering Kaleidoscope 2016.

List of participants

Naresh Patwari, IITB, http://www.chem.iitb.ac.in/people/Faculty/prof/gnp.html

Jyotishman Dasgupta, TIFR, http://jdgroup.webs.com/

Ankona Datta, TIFR, http://www.tifr.res.in/~ankona/

Ravindra Venkatramani, TIFR, http://venkatramanilab.weebly.com/

Sabuj Kumar Kundu, IIT Kanpur, http://iitk.ac.in/new/sabuj-kumar-kundu

Prashant C. Singh, IACS, http://mailweb.iacs.res.in/spectro/sppcs/

Abhishek Dey, IACS, http://mailweb.iacs.res.in/inorg/icad/

Rajarshi Chakrabarti, IITB, http://www.chem.iitb.ac.in/people/Faculty/prof/rajarshi.html

Neetu Singh, IIT Delhi, http://cbme.iitd.ac.in/content/dr-neetu-singh

Deeksha Gupta former RSC affiliate

Amit Paul, IISER Bhopal, http://https://sites.google.com/site/dramitpaul1234/

Janardan Kundu, NCL, http://academic.ncl.res.in/j.kundu

Kanishka Biswas, JNCASR, http://www.jncasr.ac.in/kanishka/

Biman Jana, IACS, http://iacs.res.in/faculty-profile.html?id=100

Kaushik Chatterjee, IISc, http://https://sites.google.com/site/iiscbiomaterials/group/resume-kaushik_chatterjee

Kana Suresan, IISER Thiruvananthapuram, http://www.iisertvm.ac.in/faculties/kms.phpx

Suman Chakraborty, NCL Pune, http://academic.ncl.res.in/profile/s.chakrabarty

Sayan Bagchi, NCL, http://academic.ncl.res.in/s.bagchi

Prasenjit Mal, NISER, http://www.niser.ac.in/~pmal/

Harinath Chakrapani, IISER Pune, http://www.iiserpune.ac.in/~harinath/

Jagannath Mondal, TCIS, http://https://www.tifrh.res.in/~jmondal/

Akash Gulyani, INSTEM, http://https://www.instem.res.in/faculty/akash

Shachi Gosavi, NCBS, http://https://www.ncbs.res.in/faculty/shachi

Ravi Prakash Singh, IIT Delhi, http://chemistry.iitd.ac.in/faculty/singhrp.html

Nidhi Jain, IIT Delhi, http://chemistry.iitd.ac.in/faculty/jain.html

Roop Mallik, TIFR, http://www.tifr.res.in/~roop/

Vaibhav Prabhudesai, TIFR, http://www.tifr.res.in/~dnap/index.php/members/people/12

Anindya Dutta, IIT Bombay, http://adutta6.wixsite.com/anindya

Acknowledgements

We acknowledge the partial funding provided by the Tata Institute of Fundamental Research and the Royal Society of Chemistry for enabling us to host the meeting.

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Footnote

† Electronic supplementary information (ESI) available. See DOI: 10.1039/c7cc90257c

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