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Abstract
Materials with multifunctional properties, such as metal-organic frameworks and ionic liquids, are critical for various technologies, such as semiconductor devices and lubricants for extreme environments. For metal-organic frameworks, the relationship between substituent groups, solvent, and electronic properties such as bandgap is unclear. Computationally, a response surface approach revealed trends between ligand substituent Hammett σm and solvent dielectric (ε) on the following electronic properties: bandgap, HOMO energy level, and LUMO energy level. For the zinc MOF-5 model variants, the HOMO and LUMO decrease with increasing σm, or a more electron withdrawing substituent. For iron MOF-5 variants, the bandgap, HOMO, and LUMO energy levels all decrease with decreasing ε and increasing σm. However, the bandgap is controlled by ε as the value of ε increases, suggesting a dipole-induced dipole interaction between the solvent and substituent group. Additionally, a non-fluorinated ionic liquid was tested experimentally for wear volume loss against a fluorinated ionic liquid and industrial lubricant. In terms of wear volume loss, the non-fluorinated ionic liquid outperformed the other lubricants with a wear volume of 0.003 mm3. Additives to this non-fluorinated ionic liquid have the potential to compete with industrial space perfluoropolyether (PFPE) lubricants, like Demnum S100 with a wear volume of 0.00045 mm3. These results inform the material design of both materials for future applications in information storage, semiconductor, and lubricant technologies.