What & Why
Cluster Spectroscopy
One of the major themes of our research group is spectroscopy and dynamics of molecular clusters. A double-barrel approach in which experiments are combined with high-level ab-initio calculations. A home-build molecular beam machine coupled to fluorescence detection and time-of-flight mass spectrometer in combination with UV and IR lasers is used to probe molecular clusters. Several laser spectroscopic techniques such as Laser Induced Fluorescence (LIF), Resonantly Enhanced Multi-photon Ionization (REMPI) and IR-UV double resonance (IDIR/FDIR) are used to probe interactions between molecules and evolution of structural polymorphs. Phys. Chem. Chem. Phys. 2019, 21, 13623-13632.
Photodissociation Dynamics
Photodissociation of molecules and molecular clusters is yet another experimental theme of our research group. Mass Spectrometry (MS) and Velocity Map Imaging (VMI) techniques are used to probe the fragments and their kinetic energies to decipher the dissociation pathways. Using a combination of MS and VMI the photodissociation of atmospherically relevant reactions and charged transfer induced dissociation pathways are investigated. Phys. Chem. Chem. Phys. 2015, 17, 434-443.
Internal Electric Fields
The distribution of solvent molecules around a solute molecules creates the local electric fields which can be used a descriptor for various chemical processes. The electric field experienced by an acid molecule in the acid–water cluster depends on its local environment comprising of surrounding water molecules. A critical electric field is required along the ionizable group is required for acid dissociation, which depends on the nature of the solvent and the solute. The concept of electric field can be used to gain molecular level understanding of proton transfer process.
Phys. Chem. Chem. Phys. 2017, 19, 7461-7464.
Molecular Dynamics
Molecular dynamics simulations allow investigation of several phenomena that occur in solution and are not amenable to quantum mechanical description. The distribution of solvent around the fluorobenzenes with increase in number of fluorine atoms lead to progressive hydrophobicity. These simulations are also used to understand the structural transformation of double-stranded nucleic acids.