Crystalline Encapsulants and Functional Materials Through Molecular Design

New York University, New York NY

Investigators

Abstract

TECHNICAL SUMMARY: Few organic solid-state systems are amenable to systematic and precise manipulation of crystal architecture and lattice metrics with predictable structural outcomes, which is crucial for the design and synthesis of molecular-based functional materials. Hydrogen-bonded frameworks based on the two-dimensional guanidinium-sulfonate (GS) sheet, however, have proven to be a benchmark in ?crystal engineering? owing to their structural robustness, which permits facile interchange of molecular constituents in selected framework architectures that often can be predicted and controlled through straightforward empirical principles. The versatility of the GS system will be exploited for (i) the synthesis of new class of GS hosts derived from a library of calixarene tetrasulfonates that form molecular baskets, suspended from the GS sheet, capable of including guest molecules within the calixarene rather than within the gallery regions between opposing GS sheets, (ii) examination of the hydrogen sorption characteristics of various guanidinium calixarenetetrasulfonates, (iii) the exploration of ferroelectric behavior associated with polar guests embedded within the suspended calixarenes, (iv) GS channel inclusion compounds with laser dyes as guests, aimed at regulating of the aggregation states of the dyes and their corresponding emission characteristics, (v) GS channel inclusion compounds with organic nitroxide guests, aimed at unraveling structure-property relationships in a new class of molecular magnets, (vi) enantioselective inclusion by chiral organomonosulfonate hosts, (vii) synthesis of discrete molecular capsules based on complementary hydrogen-bonding spacers between opposing calixarene units. NON-TECHNICAL SUMMARY: This project aims to capitalize on molecules that can be used as ?tinkertoys? to construct designer materials with optical, electronic, magnetic and storage properties that can be tuned systematically through swapping of the molecular components, which is difficult to achieve through more conventional routes. As such, these materials have to potential to impact several U.S. technologies, including data storage, communications, energy, health, and specialty chemicals, including pharmaceutical materials. Additionally, the project will provide education and research training in STEM while cultivating the next generation of scientists and engineers through (i) summer research experiences for undergraduates and faculty from minority-serving and four-year institutions through connections to the NYU Materials Research Science and Engineering Center and a Research Experiences for Undergraduates site, (ii) research experiences for high school students from various NYC schools, including the Spence School, and all-girls K-12 institution in NYC, (iii) development of courses for high school teachers enrolled in the NYU Chemistry Masters of Science for High School Educators program, thus enhancing science education in the largest and most diverse school system in the U.S., (iv) offer professional development of student and postdocs through the creation of a Northeast Solid State Chemistry Symposium that will elevate their skills and confidence in scientific presentations, (vi) expose graduate students and postdocs to scientists from industrial laboratories and other academic institutions, U.S. and international through direct research collaborations.