The major focus of our research group is on molecular-level understanding of various weak non-covalent interactions, which govern structures as well as functions of biomolecules and materials. We employ isolated gas phase laser spectroscopy techniques combined with quantum chemistry calculations to obtain intrinsic knowledge of the physical nature, strength, and binding motifs of these weak interactions. In-depth knowledge of various aspects of non-covalent interactions is extremely important for designing efficient drugs, catalysts, functional materials, supramolecular assemblies, etc. The recent ongoing research activities of our group include modulation of the strength of weak n-pi* non-covalent interaction, exploring unconventional hydrogen bonding interactions involving weakly electronegative atoms (S, Se, etc.) as hydrogen bond donor as well as acceptor, study of secondary structures of selected peptides and their sequence-dependent folding motifs, conformation-specific electronic Circular Dichroism (CD) spectroscopy of isolated molecules and weakly bound complexes, etc. All of these research problems are addressed using mass-selected Resonant 2-Photon Ionization (R2PI) and IR-UV double resonance spectroscopy in a home-built spectrometer coupled with supersonic jet-cooling, laser desorption, resonantly enhanced multiphoton ionization and Time of Flight mass spectrometry techniques. Quantum chemistry calculations are exploited to interpret the data obtained from gas phase spectroscopy. We also employ various other spectroscopic techniques such as FTIR, 2D-NMR, etc., in the solution phase as well as single crystal X-ray diffraction (XRD) technique to obtain a comprehensive picture of the structures of various molecular systems hold by a
subtle balance between multiple non-covalent interactions.