Research Projects

This project aims to integrate X-ray Quantum Crystallography (QCr) with High-Pressure Crystallography (HPCr) to gain profound insights into novel molecular materials. QCr refines electronic wavefunctions against X-ray data, yielding "experimental wavefunctions" with detailed chemical information. HPCr explores structural and interaction evolution under extreme pressure, revealing changes in bonding and electronic properties. This optimized QCr-HPCr technique will be employed to study flexible molecular materials and novel class of piezoelectrics. Rationale: Traditional inorganic piezoelectric and flexible materials often present toxicity, high production costs, and poor biocompatibility, limiting applications in areas like biomedical devices. This project addresses these challenges by focusing on biocompatible organic alternatives for flexible electronics, energy harvesting, and advanced sensors. A crucial knowledge gap exists in the atomistic understanding of the structural origin of flexibility, piezoelectricity, and flexoelectricity in these organic materials. This project fills this by exploring how pressure affects electron density and bonding. The project will apply HP-QCr to flexible crystals, molecular piezoelectrics, and organic semiconductors. Key objectives include: • Developing and optimizing HP-QCr protocols to probe structural and electronic changes in plastically and elastically flexible molecular crystalline materials. • Quantifying piezoelectric response from QCr-derived spontaneous polarization (Ps) using high-pressure X-ray data. • Building atomistic and electron density models for piezoelectricity and flexoelectricity in molecular materials. • Probing how structural deformation and internal piezoelectric responsive voltage modify band structures in molecular semiconductors using HP-QCr. Proposed Ideas & Experiments: The project will leverage Hirshfeld Atom Refinement (HAR) and X-ray Constrained Wavefunction (XCW) fitting to accurately determine in-crystal molecular dipole moments (μ), unit cell dipoles (μcell), and spontaneous crystal polarization (Ps) under variable pressure conditions. For flexoelectricity, micro-focused X-ray diffraction (µ-XRD) will be used to spatially map strain gradients and correlate them with structural polarization changes. To understand band structure modification, the team will synthesize novel chiral amine-pyrene derivatives (potential flexible organic semiconductors with piezoelectric properties) and apply HP-QCr to quantify their piezoelectric response and its effect on electronic band structure. This builds on prior work demonstrating mechanical tuning of fluorescence lifetime and bandgap in molecular semiconductor crystals. The project also aims to establish India's first single-crystal high-pressure XRD facility. The ultimate expected outcome is the design and development of next-generation, non-toxic, biocompatible molecular materials for flexible electronics, energy harvesting, and biomedical devices. Key outputs will include high-impact peer-reviewed publications and patent applications for novel materials and methodologies.