UCLA

Molecular machines have become the focus in field of physical organic chemistry given the advances in synthesis and characterization in recent decades. Identifying motions in molecular machines thus become key knowledge that researchers need in order to design and understand molecular machines. Even though molecular machines such as ATP synthase are universal in nature, designing molecular machines with complex functions remains a great challenge. To achieve such goals, one must explore basic machine functions, such as gearing, translation, locking and rotation, at the molecular level. In this dissertation, rotations are investigated under different scenarios. By virtual of modern solid-state characterization techniques and computer programs, fast rotations of molecular components in several Metal-Organic Frameworks and molecular crystals have been identified. Such knowledge is necessary to further explore emergent properties in crystalline materials and complex molecular machine functions. Chapter One is introduction of polarizable amphidynamic crystals, characterization methods, mechanisms and applications. Chapter Two describes an investigation of an open-pore Zn Metal-Organic Frameworks featuring difluorophenylene dipole and triptycene dicarboxylic acid. After discovering that the Zn MOF cannot maintain its structure upon removal of guest molecules, we sought to explore another more stable MOF system. Chapter Three describes an air-stable interpenetrated zirconium MOFs with dipoles. Solid-state NMR data and dielectric data are analyzed in depth to reveal the unique dynamics in such system. To further enhance the dipolar self ordering and simplify the structure, a dinitro derivative is also synthesized the results are recorded. Chapter Four includes the dynamics of a dumb-bell shape tribenzotriquinacene crystalline molecular rotor both experimentally and computationally. Chapter Five describes explorations on amphidynamic MOFs towards different topologies in order to achieve lattice of lower symmetry or frustrated dipolar array.