title: Synthetic Tuning of Redox, Spectroscopic, and Photophysical Properties of {Mo6I8}(4+) Core Cluster Complexes by Terminal Carboxylate Ligands.
abstract: The reactions between the tetra-n-butylammonium salt of [{Mo6I8}I6](2-) and silver carboxylates RCOOAg (R = CH3 (1), C(CH3)3 (2), α-C4H3O (3), C6H5 (4), α-C10H7 (5), or C2F5 (6)) in CH2Cl2 afforded new carboxylate complexes [{Mo6I8}(RCOO)6](2-). The complexes were characterized by X-ray single-crystal diffraction and elemental analysis, cyclic/differential pulse voltammetry, and IR, NMR, and UV-visible spectroscopies. The emission properties of the complexes 1-6, and those of the earlier reported complexes with R = CF3 (7) and n-C3F7 (8), were studied both in acetonitrile solution and in the solid state. In deaerated CH3CN at 298 K, all of the complexes 1-8 exhibit intense and long-lived emission with the quantum yield and lifetime being 0.48-0.73 and 283-359 μs, respectively. The oxidation (Eox)/reduction (Ered) potentials of the complexes correlate linearly with the pKa value of the terminal carboxylate ligands L = RCOO (pKa(L)). Reflecting the pKa(L) dependences of Eox/Ered, the emission energy (νem) of the complexes was also shown to correlate with pKa(L). The present study successfully demonstrates synthetic tuning of the redox, spectroscopic, and photophysical characteristics of a {Mo6I8}(4+)-based cluster complex with pKa(L).
authors: Nikolaev Institute of Inorganic Chemistry, Siberian Branch of the Russian Academy of Sciences , 3 Acad. Lavrentiev Prosp., 630090 Novosibirsk, Russia.
authors: Maxim A
authors: MA
authors: Mikhailov
authors: Nikolaev Institute of Inorganic Chemistry, Siberian Branch of the Russian Academy of Sciences , 3 Acad. Lavrentiev Prosp., 630090 Novosibirsk, Russia.|Novosibirsk State University , 2 Ul. Pirogova, 630090 Novosibirsk, Russia.
authors: Konstantin A
authors: KA
authors: Brylev
authors: Nikolaev Institute of Inorganic Chemistry, Siberian Branch of the Russian Academy of Sciences , 3 Acad. Lavrentiev Prosp., 630090 Novosibirsk, Russia.
authors: Pavel A
authors: PA
authors: Abramov
authors: Department of Chemistry, Faculty of Science, Hokkaido University , 060-0810 Sapporo, Japan.|Division of Chemistry and Materials Science, Graduate School of Engineering, Nagasaki University , 1-14 Bunkyo-machi, 852-8521 Nagasaki, Japan.
authors: Eri
authors: E
authors: Sakuda
authors: Department of Chemical Sciences and Engineering, Graduate School of Chemical Sciences and Engineering, Hokkaido University , 060-0810 Sapporo, Japan.
authors: Soichiro
authors: S
authors: Akagi
authors: Department of Chemistry, Graduate School of Science, Osaka City University , 558-8585 Osaka, Japan.
authors: Akitaka
authors: A
authors: Ito
authors: Department of Chemistry, Faculty of Science, Hokkaido University , 060-0810 Sapporo, Japan.|Department of Chemical Sciences and Engineering, Graduate School of Chemical Sciences and Engineering, Hokkaido University , 060-0810 Sapporo, Japan.
authors: Noboru
authors: N
authors: Kitamura
authors: Nikolaev Institute of Inorganic Chemistry, Siberian Branch of the Russian Academy of Sciences , 3 Acad. Lavrentiev Prosp., 630090 Novosibirsk, Russia.|Novosibirsk State University , 2 Ul. Pirogova, 630090 Novosibirsk, Russia.
authors: Maxim N
authors: MN
authors: Sokolov