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In this work, we synthesize and study the charge transfer properties of a oligosilyl coordination polymer formed from zirconium clusters. Although the synthesized disordered polymer lacks long range order, spectroscopic and computational evidence suggest that the metal-ligand bond is formed, and the principle crystallographic reflections closely match those simulated from inter-node spacings matching that of the ligand. The porous polymer allows for the incorporation of guest molecules as demonstrated by the intercalation of tetracyanoquinodimethane (TCNQ). Charge transfer is predicted from DFT and experimentally observed by infrared spectroscopy, solid-state 29Si nuclear magnetic spectroscopy, and voltammetry. 

Abstract Linker functionalization is a common route used to affect the electronic and catalytic properties of metal-organic frameworks. By either pre- or post-synthetically installing linkages with differing linker moieties the band gap, workfunction, and exciton lifetimes have been shown to be affected. One overlooked aspect of linker functionalization, however, has been the impact on the metal d -orbital energies to which they are bound. The ligand field differences should result in substantial changes in d -splitting. In this study we use density functional theory (DFT) to study the energetics of d -orbital energy tuning as a function of linker chemistry. We offer a general descriptor, linker pK a , as a tool to predict resultant band energies in metal-organic frameworks (MOFs). Our calculations reveal that simple functionalizations can affect the band energies, of primarily metal d lineage, by up to 2 eV and illustrate the significance of this band modularity using four archetypal MOFs: UiO-66, MIL-125, ZIF-8, and MOF-5. Together, we show that linker functionalization dramatically affects d -energies in MOF clusters and highlight that linker functionalization is a useful route for fine-tuning band edges centered on the metals, rather than linkers themselves.