To diversify metal−organic framework (MOF) structures beyond traditional Euclidean geometries and to create new chargedelocalization pathways beneficial for electrical conductivity, we constructed a novel double-helical MOF (dhMOF) by introducing a new butterflyshaped electron-rich π-extended tetrathiafulvalene ligand equipped with four benzoate groups (ExTTFTB). The face-to-face oriented convex ExTTFTB ligands connected by Zn 2 (COO) 4 paddlewheel nodes formed ovoid cavities suitable for guest encapsulation, while π−π-interaction between the ExTTFTB ligands of neighboring strands helped create new chargedelocalization pathways in iodine-mediated partially oxidized dhMOF. Iodine vapor diffusion led to oxidation of half of the ExTTFTB ligands in each double-helical strand to ExTTFTB •+ radical cations, which putatively formed intermolecular ExTTFTB/ExTTFTB •+ π-donor/ acceptor charge-transfer chains with the neutral ExTTFTB ligands of an adjacent strand, creating supramolecular wire-like chargedelocalization pathways along the helix seams. In consequence, the electrical conductivity of dhMOF surged from 10 −8 S/m up to 10 −4 S/m range after iodine treatment. Thus, the introduction of the electron-rich ExTTFTB ligand with a distinctly convex πsurface not only afforded a novel double-helical MOF architecture featuring ovoid cavities and unique charge-delocalization pathways but also, more importantly, delivered a new tool and design strategy for future development of electrically conducting stimuli-responsive MOFs.

Transforming permanently porous but electrically insulating metal–organic frameworks (MOFs) into electrically conducting materials is key to expanding their utility beyond traditional guest storage, separation, and delivery applications into the realms of modern electronics and energy technologies. To this end, herein, we have converted a highly porous but intrinsically insulating NU-1000 MOF into semiconducting NU-1000/gold nanoparticle (AuNP) and NU-1000/polydopamine/AuNP composites via MOF- and polymer-induced reduction of infiltrated Au3+ ions into metallic AuNPs. The NU-1000/AuNP and NU-1000/PDA/AuNP composites not only gained significant room temperature electrical conductivity (∼10–7 S/cm), which was ca. 104 times greater than any MOF/metal nanoparticle (MNP) composites exhibited thus far under the same conditions, i.e., without photoinduction and thermal induction, but also retained sizable porosity and surface areas (1527 and 715 m2/g, respectively), which were also larger than most intrinsically conducting 3D MOFs developed to date. The markedly higher conductivities of the NU-1000/AuNP and NU-1000/PDA/AuNP composites can be attributed to more efficient charge hopping or tunneling through well-dispersed AuNPs embedded inside the crystalline MOF matrix, which pristine NU-1000 lacked. Thus, this work presented an effective new strategy to transform porous but nonconducting MOFs into electrically conducting MOF/MNP composites with considerable porosity, which could be useful in future electronics, electrocatalysis, and energy storage devices.

Thermodynamically favored simultaneous coordination of Pt(II) corners with aza- and carboxylate ligands yields tricomponent coordination complexes with sophisticated structures and functions, which require careful structural characterization to paint accurate depiction...

Ruthenium(iii) complexes are known for their high stability and inertness. To the best of our knowledge, the only well-characterized example of a labile Ru(iii) complex is [Ru(edta)(HO)] as a consequence of an intramolecular hydrogen bonding leading to the formation of a large opening in the molecule front, thus changing the mechanism from dissociative to associative. Compelling experimental evidence is presented demonstrating that the [Ru(phtpy)Cl] complex is labile, also indicating that the Ru(iii)-phtpy bond is much weaker than expected, in contrast to the strongly π-back-bonding stabilized Ru(ii)-phtpy bond.