Fig. 3: The relationship between linker pKa and LUMO energy.
From: Ligand field tuning of d-orbital energies in metal-organic framework clusters
a Functionalized ligands considered in this study. b The computed pKa is a good descriptor for the neutral linker LUMO (i.e., their electron affinity). The trend is linear (R2 = 0.95) for functional groups appended to either the C1 position on the imidazole, or any position on the aromatic benzene dicarboxylate. Dichloro-functionalized imidazole is relatively acidic but has an unusually high LUMO energy, as the chloro groups withdraw density from the C = C bond, which comprises the LUMO (see Fig. S3).
