Research

Polymorphism

The existence of a given compound (organic, inorganic, metalorganic, macromolecule in multiple phases is of significance in the understanding of structure-property relationships in crystalline compounds. This can arise from changes in molecular conformation or packing features in the crystal lattice.
Methods of Crystal Growth: Slow evaporation, Solvent diffusion, Vapour Diffusion, Melt Crystallization, Sublimation.
Characterization Methods: Single Crystal X-ray Diffraction, Powder X-ray Diffraction, Differential Scanning Calorimetry, Thermogravimetric Analysis, Hot Stage Microscopy.

Cocrystallization

Apparatus: Optical heating and crystallization device (OHCD), Single crystal X-ray diffraction.

Pharmaceutical Cocrystallization

Pharmaceutical cocrystals are composed of one Active Pharmaceutical Ingredient (API) and other molecular substance (Coformer/ Excipient), which is generally regarded as safe (GRAS) according to World Health Organisation (WHO). For this, the selective choice of coformers could be achieved with an adequate knowledge on crystal engineering. Therefore, the design of solid-state materials with desired physical and chemical properties, by the utilization of specific noncovalent interactions can be engineered, by understanding the organization of the molecules that govern the crystal packing.

Electrical Properties in Molecular Crystals

Synthesis of dielectric materials and their potential application as triboelectric nanogenerator.

Mechanical Properties of Molecular Crystals

Exploring mechanical properties of molecular solids offers a unique opportunity to evaluate structure-properties correlation in the context of crystal engineering. Also, the quantitative understanding of mechanical properties of solids provides a molecular basis of different microscopic/macroscopic phenomena through the assessment of nature and energetic of various non-covalent interactions.

Solid State Photophysical Properties

The solid-state absorption and emission spectra corroborate considerably with the nature and strength of non-covalent intermolecular interactions and also with the orientation of molecules in the crystalline lattice of co-crystals.

Ab-initio Calculations

Performing Ab-initio calculations for the quantitative understanding of non-covalent interactions present in molecular crystals has become a very important part of crystallographic studies. Availability of high-level post-HF methods such as Møller–Plesset perturbation theory (MP2), Configuration interaction (CI), Coupled cluster (CC), Quadratic configuration interaction (QCI), Quantum chemistry composite results in an accurate calculation of properties such as lattice energies, binding energies, electrostatic potentials etc.
Software: Gaussian09, NBO, GAMESS-US.

Crystal Structure Prediction

Crystal structure prediction (CSP) methods for organic molecules have attracted tremendous interest in recent years. These are based on searches for the most thermodynamically feasible crystal structure, and such an evaluation neglects the role of entropy and the kinetics of crystallization. The role of the solvent, temperature, pressure and other related kinetic factors may lead to the formation of alternative crystalline polymorphs. The existence of all possible polymorphic forms in experimentally determined crystal structures is difficult to predict using empirical methods practiced in the prediction of crystal structures of an organic molecule. CSP, once conceived to be a challenging exercise, has been successfully performed on rigid molecules and the success achieved from the first four blind tests is a testimony to this fact.
Software: Material Studio, Mercury

In situ cryocrystallization

In situ cryo crystallization is a technique to determine the molecular structure of a compound, which is a liquid at room temperature using the technique of Single Crystal X-Ray diffraction (SCXRD). This allows for the determination of the position of all the atoms in the molecule of interest. This method can be applicable for compounds which are low melting solids, ionic liquids, and gaseous hydrates at room temperature. The crystallization of a liquid in a glass capillary and the determination of the structure enables an unequivocal characterization of drugs, pharmaceuticals, agrochemicals and technologically important materials.
Apparatus: Optical heating and crystallization device (OHCD), Single crystal X-ray diffraction.

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