Aluminum Metal-organic Frameworks Based on Metalloporphyrins and Sorption of Archetypal Organosulfur Compounds
Abstract
This project has focus on mechanistic studies of reactions of new aluminum metal-organic frameworks (MOFs) denoted Al-MOF-MeTCPP which contain Cu, Ni and Zn metalloporphyrins as linkers, with organosulfur compounds of the archetypal molecular structure. In the recent decade, MOFs were widely investigated for sorption and catalysis; certain MOFs were studied for catalytic deactivation of Chemical Warfare Agents (CWAs). In 2017, the PI published a book, ÒAdsorption on Mesoporous Metal-Organic Frameworks in Solution for Clean Energy, Environment and HealthcareÓ. Aluminum MOFs (Al-MOFs) contain organic linkers of variable structure for selective recognition and bonding of organic molecules, and show an outstanding chemical stability and low toxicity. Surprisingly, they were not studied for sorption or optical detection of organosulfur compounds which resemble CWAs. In this project, we address synthesis, kinetics, mechanism, and the selectivity of Al-MOF-MeTCPP as sorbents of organosulfur compounds, and changes in their optical properties upon adsorption. Objective I. Synthesis and characterization of Al-MOF-MeTCPP (Me = Cu2+, Ni2+, Zn2+) by powder XRD and FTIR spectroscopy. Objective II. Mechanistic studies of sorption of the archetypal organosulfur compounds on Al-MOF-MeTCPP, formation of adsorption complexes, and studies of the selectivity of sorption. The compounds contain ÐSÐ or S=O groups present in the molecules of CWAs and their deactivation products. The sorption will be studied in a) air and b) aqueous solution. We will determine chemical kinetics of sorption by GC-MS and HPLC-UV, the stoichiometry, and bonding mechanism in the adsorption complexes by spectroscopic methods. Objective III. Characterization of optical properties of Al-MOF-MeTCPP and their adsorption complexes. Major optical transitions (absorption and emission of light) in the near-UV, visible and NIR ranges will be studied by new, ultra-high resolution solid-state synchronous fluorescence spectroscopy, SS-SFS. It was pioneered in PIÕs lab few years ago, and showed an unprecedented performance vs. the existing methods. We will systematically study how absorption, fluorescence transitions, and color of Al-MOF-MeTCPP change upon sorption of the archetypal organosulfur compounds. We hypothesize that the SS-SFS spectra of adsorption complexes show the selective quenching of transitions of the MeTCPP linker, and changes in the vibronic structure of the fluorescence spectra. The proposed fundamental experimental studies will lead to significant breakthroughs in the materials chemistry of MOFs of interest to Army Research Office (ARO). They will reveal new family of porphyrin-based Al-MOFs as an advanced chemical platform for selective sorption and facile detection of organosulfur compounds. Potential applications include Òsmart patchesÓ on the soldier uniform which change color upon exposure to CWA, selective sorbents in gas masks, and the remotely recognizable tags for robust detection of contamination and decontamination. This project is conducted at Morgan State University (MSU), a research active Historically Black College and University (HBCU). MSU in the City of Baltimore serves a predominantly African-American population, an underrepresented minority (URM) group in STEM. The project will lead to significant increase of capacity of MSU to participate in the research by Department of Defense, education of URM students via research in chemistry lab, encouraging them to pursue careers in STEM, and teaching new and revised undergraduate and graduate courses.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jul 20, 2020
- Source ID
- W911NF2010290
Entities
People
- Alexandr Samokhvalov
Organizations
- Army Contracting Command
- Morgan State University
- Office of the Secretary of Defense