ic6b01042_si_001.cif (5.27 MB)
Synthetic Tuning of Redox, Spectroscopic, and Photophysical Properties of {Mo6I8}4+ Core Cluster Complexes by Terminal Carboxylate Ligands
dataset
posted on 2016-08-09, 10:48 authored by Maxim A. Mikhailov, Konstantin A. Brylev, Pavel
A. Abramov, Eri Sakuda, Soichiro Akagi, Akitaka Ito, Noboru Kitamura, Maxim N. SokolovThe
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).
