Metal-Organic Frameworks with Zero and Low-Valent Metal Nodes Connected by Tetratopic Phosphine Ligands

Metal-organic frameworks (MOFs) constructed with M-0 nodes are attractive targets due to the reactivity of these low-valent metals, but examples of these MOFs remain exceedingly rare. The rational design of three-dimensional MOFs with Pd-0 and Pt-0 nodes using tetratopic phosphine ligands is reported. Five new MOFs have been synthesized by systematic variation of the phosphine ligands and metal precursors employed, and these represent the first examples of MOFs constructed using phosphine-metal bonds as the sole structural component. The MOFs display solid-state luminescence, with emission maxima that are significantly red-shifted compared to Pd(PPh3)(4). In addition, a Rh-I low-valent coordination solid based on the same linker design is reported, which displays solid-state luminescence that is not observed for the molecular analogue.

Automated summary

This study reports the rational design and synthesis of three-dimensional metal-organic frameworks (MOFs) with Pd-0 and Pt-0 nodes using tetratopic phosphine ligands. Five new MOFs have been synthesized by varying the phosphine ligands and metal precursors, and they are the first examples of phosphine-metal bonded MOFs. These MOFs exhibit solid-state luminescence with significantly red-shifted emission maxima compared to Pd(PPh3)(4). Additionally, a Rh-I low-valent coordination solid based on the same linker design is reported, which displays solid-state luminescence not observed in the molecular analogue.