Date of Award
6-26-2026
Date Published
August 2026
Degree Type
Dissertation
Degree Name
Doctor of Philosophy (PhD)
Department
Chemistry
Advisor(s)
Timothy Korter
Subject Categories
Chemistry | Physical Chemistry | Physical Sciences and Mathematics
Abstract
Low-frequency vibrational spectroscopy provides a sensitive approach for characterizing polymorphism and intermolecular dynamics in organic molecular crystals. Terahertz time-domain spectroscopy (THz-TDS) and low-frequency Raman spectroscopy probe collective lattice vibrations arising from weak intermolecular interactions, offering direct insight into crystal packing, phase stability, and structural organization that is often inaccessible to conventional diffraction and mid-infrared techniques. To interpret these modes, experimental measurements are combined with periodic solid-state density functional theory (ss-DFT), which enables vibrational assignments to specific intermolecular motions, and crystal structure prediction (CSP), which maps accessible polymorphic energy landscapes. Together, these methods form a unified experimental–computational framework for understanding molecular solids. This work further considers practical experimental and computational challenges, along with detailed approaches to data analysis and interpretation. It also includes THz sample preparation and modeling of weak intermolecular forces and applies the approach to predominantly pharmaceutically relevant systems. Overall, the integration of low-frequency spectroscopy with ss-DFT and CSP enables detailed characterization of polymorphism and advances understanding of structure–property relationships in molecular materials.
Access
Open Access
Recommended Citation
Zarrella, Salvatore, "Using Low-Frequency Vibrational Spectroscopy to Develop Analytical Profiles for Polymorphic Organic Molecular Crystals" (2026). Dissertations - ALL. 2360.
https://surface.syr.edu/etd/2360
