Dr.Sunil Varughese

Dr.Sunil Varughese
  • Dr.Sunil Varughese
  • Principal Scientist
  • 0471-2515438

Personal

Sunil Varughese received his M.Sc. degree in Chemistry (2002) from School of Chemical Sciences, Mahatma Gandhi University, Kottayam. He obtained his PhD in Chemistry in 2007 from National Chemical Laboratory, Pune (University of Pune) under the guidance of Dr. V. R. Pedireddi (currently at IIT Bhubaneshwar). After two year’s post-doctoral research (2007– 2009) with Professor Sylvia M. Draper at Trinity College Dublin, he worked as a DST Young Scientist (2009– 2013) in the research group of Professor Gautam R. Desiraju at Indian Institute of Science, Bangalore. During 2013-2016 he was a Scientist Fellow at National Institute for Interdisciplinary Science and Technology (CSIR-NIIST), Trivandrum. Currently, he is a Senior Scientist in the Chemical Sciences and Technology Division in CSIR-NIIST.

Research Career

  1. Senior Scientist
    October 2016 – to date
    Chemical Science and Technology Division
    CSIR-National Institute for Interdisciplinary Science and Technology
  2. Scientist (Fellow)
    January 2013 – January 2016
    Chemical Science and Technology Division
    CSIR-National Institute for Interdisciplinary Science and Technology
  3. DST Young Scientist
    April 2010 – January 2013
    Solid State and Structural Chemistry Unit
    Indian Institute of Science Bangalore
  4. IISc Postdoctoral Fellow
    August 2009 – March 2010
    Solid State and Structural Chemistry Unit
    Indian Institute of Science Bangalore
  5. Science Foundation Ireland Postdoctoral Fellow
    July 2007 – August 2009
    School of Chemistry
    Trinity College, Dublin, Ireland

Professional Affiliations

  1. Royal Society of Chemistry (RSC): Member
  2. American Chemical Society (ACS): Member
  3. British Crystallographic Association (BCA): Member
  4. Indian Crystallographic Association (ICA): Life Member

Ongoing projects

  • Nanomechanical Response in Organic Crystals: Molecular Basis of Mechanically Induced Structural Transformations (DST-SERB, New Delhi).
  • Knowledge-based Development of Formulations of Selected Generic Drugs (KSDPL, Kerala)

Completed projects

  • Mechanical Stimulation Induced Microscopic Crystalline Structure Changes in Molecular Materials: Implications on Drug Formulation and Mechanochromic Behavior (DST-SERB, New Delhi)
  • Pharmaceutical formulations by applying crystal engineering principles (DST, New Delhi)
  • Stimuli induced phase transition: A facile route to modulate optical properties in molecular crystals (DST, New Delhi)

Collaborators

  • Prof. Gautam Desiraju (IISc Bangalore)
  • Prof. Krystof Wozniak (University of Warsaw, Poland)
  • Prof. U. Ramamurty (IISc Bangalore)
  • Prof. C. Malla Reddy (IISER Kolkata)
  • Dr. Tejender S. Thakur (CSIR-CDRI, Lucknow)
  • Dr. M. S. R. N. Kiran (SRM University, Chennai)

Home

Sunil Varughese is a structural chemist with expertise in structure-property correlations in molecular materials. He uses concepts of crystal engineering and non-covalent synthetic methodologies to design molecular materials. He has several years of experience in the studies of polymorphism and phase transition behavior in active pharmaceutical ingredients (APIs). His current research focuses on the mechanical properties of molecular crystals (studied using nanoindentation technique) in terms of compositional variations, spatial packing efficiency and hydrogen-bond connectivity. The flexibility and the weak energetics involved in intermolecular interactions are used to adopt a non-covalent/supramolecular strategy to modify the molecular arrangements and crystal packing and thereby to tune the fluorescence properties of molecular materials.

Researcher ID :   C-4613-2008 
ORCID ID         :   https://orcid.org/0000-0003-0712-915X

Selected publications

 

  • Molecular Basis for the Mechanical Response of Sulfa Drug Crystals. S. SeethaLekshmi, M. S. R. N. Kiran, U. Ramamurty*, and Varughese*
    Chemistry, A European Journal 2019, 25, 526-537
  • Lanthanide complex-derived white-light emitting solids: A survey on design strategies S. SeethaLekshmi, A. R. Ramya, M. L. P. Reddy, and Varughese*
    Journal of Photochemistry and Photobiology C: Photochemistry Reviews 2017, 33, 109.
  • Non-covalent routes to tune the optical properties of molecular materials. Varughese*
    Journal of Materials Chemistry C 2014, 2, 3499-3516.
  • Odd–even effect in the elastic modulii of alpha,omega -alkanedicarboxylic acids. M. K. Mishra, S. Varughese, U. Ramamurty,G. R. Desiraju
    Journal of the American Chemical Society 2013, 135, 8121.
  • Nanoindentation in crystal engineering: quantifying mechanical properties of molecular crystals. S. Varughese,M. Kiran, U. Ramamurty, G. R. Desiraju
    Angewandte Chemie International Edition 2013, 52, 2701.
  • Nanoindentation as a Probe for Mechanically-Induced Molecular Migration in Layered Organic Donor–Acceptor Complexes.. S. Varughese, M. S. R. N. Kiran, U. Ramamurty, G. R. Desiraju
    Chemistry-An Asian Journal 2012, 7, 2118.
  • Interaction anisotropy and shear instability of aspirin polymorphs established by nanoindentation.S. Varughese, M. S. R. N. Kiran, K. A. Solanko, A. D. Bond, U. Ramamurty, G. R. Desiraju
    Chemical Science 2011, 2, 2236.
  • Switching and tuning organic solid-state luminescence via a supramolecular approachS. P. Anthony, S.Varughese, S. M. DraperChemical Communications. 2009, 7500-7502.
  • A Competitive Molecular Recognition Study: Syntheses and Analysis of Supramolecular Assemblies of 3,5-Dihydroxybenzoic
    Acid and Its Bromo Derivative with Some N-Donor Compounds. S. Varughese, V. R. Pedireddi Chemistry, A European Journal, 2006, 12, 1597.
  • Hydrogen bond mediated open-frame networks in coordination polymers : Supramolecular assemblies of Pr(III) and 3,5-dinitro-4-methylbenzoic acid with aza-donor compounds.S. Varughese, V. R. Pedireddi
    Chemical Communications, 2005, 1824.

Reach me @

Email: s.varughese@niist.res.in
Researchgate: https://www.researchgate.net/profile/Sunil_Varughese_Phd
LinkedIn: https://www.linkedin.com/in/sunil-varughese-phd-4355733a/
GoogleScholar: https://scholar.google.co.in/citations?user=xK3Kg9gAAAAJ&hl=en
Twitter: @SunVarughese

Publications

Recent Publications:

  • Enhanced Aqueous Solubility of the Solid Forms of a BCS Class-II
    Anti-Tuberculosis Drug, Prothionamide. Amrutha, L. Giri, S. SeethaLekshmi* and S.Varughese*
    Crystal Growth & Design 2020, 20, 5086-5096
  • Phase Transitions and Anisotropic Mechanical Response in a Water-rich Trisaccharide Crystal S. SeethaLekshmi, M.S.R.N. Kiran, U. Ramamurty, S.Varughese*
    Crystal Growth & Design 2020, 20, 442-448.
  • Structural Landscape of an Antimicrobial Sulfa Drug, Sulfachloropyridazine: Polymorphs, Solvates and Co-crystals S. SeethaLekshmi, S. Amrutha, M.S.R.N. Kiran, S.Varughese*
    Crystal Growth & Design 2019, 19, 3222-3232.
  • Molecular Basis for the Mechanical Response of Sulfa Drug Crystals S. SeethaLekshmi, M.S.R.N. Kiran, U. Ramamurty, S.Varughese*
    Chemistry, A European Journal 2019, 25, 526-537.
  • Lanthanide complex-derived white-light emitting solids: A survey on design strategies S. SeethaLekshmi, A.R. Ramya, M.L.P. Reddy, S. Varughese*
    Journal of Photochemistry and Photobiology C: Photochemistry Reviews 2017, 33, 109–131.
  • Structural and Energetic Analysis of Molecular Assemblies in a Series of Nicotinamide and Pyrazinamide Cocrystals with Dihydroxybenzoic Acids. K. N. Jarzembska, A. A. Hoser, S. Varughese, R. Kaminski,
    M. Malinska, M. Stachowicz, V. R. Pedireddi, and K. Wozniak
    Crystal Growth & Design 2017, 17, 4918-4931.
  • Structural Snapshots of Metastable Intermediates Reveals Sequential Addition of Growth Units in the Formation of an Archetypal Coordination Complex: Anisotropic Layer Migration and Solid-State Thermochromic Transitions. S. SeethaLekshmi, M. S. R. N. Kiran, U. N. S. Hareesh, U. Ramamurty* and S. Varughese*
    Crystal Growth & Design 2016, 16, 7271-7277.
  • Positional isomerism and conformational flexibility directed structural variations in the molecular complexes of dihydroxybenzoic acids. Varughese*, A. A. Hoser*, K. N. Jarzembska, V. R. Pedireddi and K. Wo?niak
    Crystal Growth & Design 2015, 15, 3832-3841.
  • Equivalence of ethylene and azo-bridges in the modular design of molecular complexes: role of weak interactions. Ravat, S. SeethaLekshmi, S. N. Biswas, P. Nandy, and S. Varughese*
    Crystal Growth & Design 2015, 15, 2389-2401.

After joining CSIR-NIIST:

  • Crystal Growth & Design 2015, 15, 3832-3841
  • Crystal Growth & Design 2015, 15, 2389-2401
  • Crystal Growth & Design 2014, 14, 4143-4154
  • Dalton Transactions 2014, 43, 10940-10946
  • Journal of Materials Chemistry C 2014, 2, 3499-3516

Other selected publications:

  • Journal of the American Chemical Society 2013, 135, 8121-8124
  • Angewandte Chemie International Edition 2013, 52, 2701-2712
  • Chemistry-An Asian Journal 2012, 7, 2118-2125
  • Chemical Science 2011, 2, 2236-2242
  • Chemical Communications. 2009, 7500-7502
  • Chemistry, A European Journal, 2006, 12, 1597-1609
  • Chemical Communications, 2005, 1824-1826
  • Inorganic Chemistry, 2004, 43, 450-457

Research Interest

Our studies explore the crystal engineering routes to tune the physicochemical properties of APIs by developing new solid forms, and the approach remains as an attractive prospect. We integrate the concepts of high-throughput screening and combinatorial synthesis in the solid-state form screening. The resultant products get screened using diffraction (single crystal and powder), microscopy (optical and electron), thermal (DSC and hot-stage microscopy) and spectroscopy (IR and Raman) techniques. Nanoindentation on precise crystal faces provides insights on the structure-mechanical property correlations that can be extrapolated to the tabletability of the crystal forms under investigation.

Current interest

  • Crystal engineering of organic pharmaceutics for better therapeutic applications
  • Polymorphism and phase transition behavior in molecular materials
  • Structure-mechanical property correlations in molecular crystals
  • Porous frameworks and carbonaceous materials for gas storage and water purification
  • Non-covalent synthetic strategy to tune the emission characteristics of molecular emissive materials