- Collection:
- Atlanta University and Clark Atlanta University Theses and Dissertations
- Title:
- Synthesis of anthracene and stilbene-containing metalorganic frameworks and their behavior in fluorescence based detection of nitroaromatic compounds and adsorption of carbon dioxide, respectively, 2020
- Creator:
- Golafale, Saki T.
- Date of Original:
- 2020-05
- Subject:
- Degrees, Academic
Dissertations, Academic - Location:
- United States, Georgia, Fulton County, Atlanta, 33.749, -84.38798
- Medium:
- theses
dissertations - Type:
- Text
- Format:
- application/pdf
- Description:
- This research focuses on the synthesis of anthracene and stilbene-containing metal-organic frameworks (MOFs) for use in addressing two major environmental concerns; the detection of nitroaromatic compounds (NACs), and the capture of carbon dioxide from the atmosphere. MOFs are multi-dimensional coordination polymers (CPs) made by linking organic ligands and metal ions. A series of lanthanide metal ions (Pr3+, Nd3+, Eu3+, Gd3+, Tb3+, Dy3+, Ho3+, Er3+, Tm3+, and Yb3+) combined with the ligand, 9,10-anthracenedicarboxylic acid (H2ADC), under solvothermal conditions, afforded ten new isostructural 2-dimensional (D) layered MOFs. Each layer is composed of intersecting open rings from the linking of covalently bonded -Ln-ADC-Ln- species (Ln = lanthanide). The Ln-ADC structures showed ligand-based fluorescence with fast component excited state lifetimes, τ1, in the range of 0.087 to 0.986 nanoseconds (ns). The structures showed ligand-based emission, with spectra blue-shifted compared to the free H2ADC which are attributed to the rigidified isolated monomeric ligand species. The Ln-ADC MOFs were effective for the fluorescence-based detection of NACs (nitrobenzene, 4-nitroaniline, 2,4-dinitrodiphenylamine, and 2,4-dinitrophenylhydrazine) based on collisional quenching phenomena as determined by linear Stern-Volmer plots. The quenching constants, Ksv, were in the range of 2.1 x104 to 1.8 x 105 M-1. The combination of the ligand, 2,2’-diamino-4,4’-stilbenedicarboxylic acid (H2DASDC), with lanthanides (Er3+, Tm3+, and Yb3+) and transitional metal (Cd2+) ions, under solvothermal conditions, afforded three new isostructural non-interpenetration 3-D Ln MOFs and a 1-D cadmium CP. All structures exhibited ligand-based fluorescence. Whereas the fluorescence from the Ln-DASDC and H2DASDC were quenched, the Cd-DASDC structure showed strong fluorescence and a radiative lifetime of 0.80 ns. The combination of the ligand, 2,2’-dinitro-4,4’-stilbenedicarboxylic acid (H2DASDC), with bipyridine co-ligands, and a range of transition metal ions yielded nine new 1-D and 3-D Tm-DNSDC MOFs (Tm = Co, Mn, Ni, and Zn). At 1 atm, the Co and Mn-DNSDC MOFs showed CO2 adsorption capacities of 1.84 mmol g-1, 2.17 mmol g -1, 1.22 mmol g -1 at 256, and 273 K. The adsorption isotherms were best fitted by the Langmuir and Freundlich models, and the heats of adsorption values < 50 kJ/mol, indicated that physisorption occurred on heterogeneous surfaces of the Tm-DNSDC structures.
Date of award: 2020-05
Degree type: dissertation
Degree name: Doctor of Philosophy (PhD)
Granting institution: Clark Atlanta University
Department: Department of Chemistry
Advisor: Ingram, Conrad - Metadata URL:
- http://hdl.handle.net/20.500.12322/cau.td:2020_golafale_saki_t
- Holding Institution:
- Atlanta University Center Robert W. Woodruff Library
- Rights:
-
