ic401673z_si_001.pdf (952.15 kB)
Preferential Behavior on Donating Atoms of an Ambidentate Ligand 2‑Methylisothiazol-3(2H)‑one in Its Metal Complexes
journal contribution
posted on 2013-12-02, 00:00 authored by Masaru Kato, Kei Unoura, Toshiyuki Takayanagi, Yasuhisa Ikeda, Takashi Fujihara, Akira NagasawaFive
metal complexes of 2-methylisothiazol-3(2H)-one (MIO),
[CoIII(NH3)5(MIO)]3+,
[RuII(NH3)5(MIO)]2+, [RuIII(NH3)5(MIO)]3+, [PtIICl3(MIO)]−, and trans-[UVIO2(NO3)2(MIO)2], were synthesized, and their
structures were determined by single-crystal X-ray crystallography.
MIO is an ambidentate ligand and coordinates to metal centers through
its oxygen atom in the cobalt(III), ruthenium(III), and uranium(VI)
complexes and through its sulfur atom in the ruthenium(II) and platinum(III)
complexes. This result suggests that MIO shows preferential behavior
on its donating atoms. We also studied the electron-donor abilities
of the oxygen and sulfur atoms of MIO. Various physical measurements
on the conjugate acid of MIO and the MIO complexes allowed us to determine
an acid dissociation constant (pKa) and
donor number (DN) for the oxygen atom of MIO and Lever’s electrochemical
parameter (EL) and a relative covalency
parameter (kL) for the sulfur atom.
