Octahedral Hexanuclear Rhenium Cluster Dimers Bridged by Pyrazine or 4,4'-Bipyridine with 23- and 24-Electron Configurations.

New pyrazine (pz)- and 4,4'-bipyridine (4,4'-bpy)-bridged octahedral hexanuclear rhenium(III) cluster dimers, [{Re(μ-S)Cl}(μ-L)] (L = pz, []; L = 4,4'-bpy, []), with 2 × 24 d-electrons {Re(24e)} were obtained in a single-step reaction via photoirradiation of [Re(μ-S)Cl] with L in a 2:1 ratio at room temperature. The {Re(23e)} dimers, [{Re(μ-S)Cl}(μ-L)] (L = pz, []; L = 4,4'-bpy, []), were synthesized through two-electron oxidation of [] and [], respectively. The single-crystal X-ray structures of [] and [] were determined, revealing structural distortion of the Re core of [] due to the Jahn-Teller effect.

Luminescence Color and Intensity Changes of Nitridorhenium(V) Complexes Induced by Protonation/Deprotonation on the Bidentate Azolylpyridine Ligands.

Tricyanidonitridorhenium(V) complexes with azolylpyridines, namely, [ReN(CN)(H-N2py)] (, H-N2py = 2-(3-pyrazolyl)pyridine) and [ReN(CN)(L)] (, L = 2-[1,2,3]-triazol-4-yl-pyridine anion (N3py), and , that is, L = 2-(tetrazol-5-yl)-pyridine anion (N4py)), were newly synthesized and characterized. The structures of the new complexes were determined by single-crystal X-ray analysis. The complex includes two geometrical isomers in which an isomer is the conformation with the pyridyl (py) and pyrazolyl (pyrz) moieties of H-N2py occupying the site to the nitrido (the ax site) and the site to the cyanido (the eq site), respectively, in a bidentate fashion; the other isomer is the py and pyrz moieties coordinated to the eq and ax sites.

Tuning the Ground- and Excited-State Redox Potentials of Octahedral Hexanuclear Rhenium(III) Complexes by the Combination of Terminal Halide and N-Heteroaromatic Ligands.

The present study reports that the ground- and excited-state Re(23e)/Re(24e) redox potentials of an octahedral hexanuclear rhenium(III) complex can be controlled by systematically changing the number and type of the -heteroaromatic ligand (L) and the number of chloride ions at the six terminal positions. Photoirradiation of [Re(μ-S)Cl] with an excess amount of L afforded a mono-L-substituted hexanuclear rhenium(III) complex, [Re(μ-S)Cl(L)] (L = 4-dimethylaminopyridine (dmap), 3,5-lutidine (lut), 4-methylpyridine (mpy), pyridine (py), 4,4'-bipyridine (bpy), 4-cyanopyridine (cpy), and pyrazine (pz)). The bis- and tris-lut-substituted complexes, - and -[Re(μ-S)Cl(lut)] and -[Re(μ-S)Cl(lut)], were synthesized by the reaction of [Re(μ-S)Cl] with an excess amount of lut in refluxed ,-dimethylformamide.

Fibroblast activation protein targeted therapy using [Lu]FAPI-46 compared with [Ac]FAPI-46 in a pancreatic cancer model.

Purpose: Fibroblast activation protein (FAP), which has high expression in cancer-associated fibroblasts of epithelial cancers, can be used as a theranostic target. Our previous study used Cu and Ac-labelled FAP inhibitors (FAPI-04) for a FAP-expressing pancreatic cancer xenograft imaging and therapy. However, the optimal therapeutic radionuclide for FAPI needs to be investigated further.

Synthesis, Structures, and Photoluminescent Properties of Tricyanidonitridorhenium(V) Complexes with Bipyridine-Type Ligands.

Tricyanidonitridorhenium(V) complexes with 2,2'-bipyridine (bpy) derivatives in which the 4 and 4' positions were substituted by X, [ReN(CN)(Xbpy)] (X = NMe, NH, OMe, Me, Cl, and Br), were newly synthesized and characterized. The structures of the new complexes were determined by single-crystal X-ray analysis. UV-vis spectra of the complexes in dimethyl sulfoxide (DMSO) showed that the peak maximum wavelengths of rhenium-to-π* bpy-type-ligand charge transfer were in the range of 474-542 nm.

Synthesis and Photoluminescence of Tetracyanidonitridorhenium(V) Complexes with Five-Membered N-Heteroaromatic Ligands and Photoluminescence-Intensity Change.

Novel tetracyanidonitridorhenium(V) complexes with five-membered N-heteroaromatic ligands, (PPh)[ReN(CN)L] [L = imidazole (Him) (), 1-methylimidazole (Mim) (), and pyrazole (pyz) ()] and (PPh)[ReN(CN)L]·L [L = Him () and Mim ()], were synthesized by the reactions of (PPh)[ReN(CN)] () with Him, Mim, and pyz, and their structures were determined by single-crystal X-ray analysis. The complexes , , , and showed intense photoluminescence, with the emission quantum yields (Φ) being 0.65-0.

Theranostics Targeting Fibroblast Activation Protein in the Tumor Stroma: Cu- and Ac-Labeled FAPI-04 in Pancreatic Cancer Xenograft Mouse Models.

Fibroblast activation protein (FAP), which promotes tumor growth and progression, is overexpressed in cancer-associated fibroblasts of many human epithelial cancers. Because of its low expression in normal organs, FAP is an excellent target for theranostics. In this study, we used radionuclides with relatively long half-lives, Cu (half-life, 12.

Synthesis, structures, redox properties, and theoretical calculations of thiohalide capped octahedral hexanuclear technetium(iii) clusters.

The first thiohalide μ-capped octahedral hexanuclear technetium clusters with 24 valence electrons, [Tc(μ-S)(μ-Br)Br] [n = 1 ([Tc-SBr]) and n = 2 ([Tc-SBr])] and [Tc(μ-S)(μ-Cl)Cl] ([Tc-SCl]), were synthesized and characterized. The structures of [Tc-SBr], [Tc-SBr], and [Tc-SCl] were determined by single-crystal X-ray analysis. The Tc-Tc bond distances in [Tc-SBr], [Tc-SBr], and [Tc-SCl] are 2.

A luminescent dicyanidonitridotechnetium(v) core with tridentate ligand coordination sites.

A novel, luminescent technetium complex, [TcN(CN)2bpa] (bpa = bis-(2-pyridylmethyl)amine), with tridentate ligand coordination sites was synthesized and characterized. Photoemission with a maximum wavelength at 666 nm was observed in the solid-state at 296 K.