10.1021/ic401673z.s001
Masaru Kato
Masaru
Kato
Kei Unoura
Kei
Unoura
Toshiyuki Takayanagi
Toshiyuki
Takayanagi
Yasuhisa Ikeda
Yasuhisa
Ikeda
Takashi Fujihara
Takashi
Fujihara
Akira Nagasawa
Akira
Nagasawa
Preferential Behavior on Donating Atoms of an Ambidentate Ligand 2‑Methylisothiazol-3(2<i>H</i>)‑one in Its Metal Complexes
American Chemical Society
2013
MIO
sulfur atom
EL
DN
oxygen atom
Metal ComplexesFive metal complexes
2013-12-02 00:00:00
Journal contribution
https://acs.figshare.com/articles/journal_contribution/Preferential_Behavior_on_Donating_Atoms_of_an_Ambidentate_Ligand_2_Methylisothiazol_3_2_i_H_i_one_in_Its_Metal_Complexes/2348215
Five
metal complexes of 2-methylisothiazol-3(2<i>H</i>)-one (MIO),
[Co<sup>III</sup>(NH<sub>3</sub>)<sub>5</sub>(MIO)]<sup>3+</sup>,
[Ru<sup>II</sup>(NH<sub>3</sub>)<sub>5</sub>(MIO)]<sup>2+</sup>, [Ru<sup>III</sup>(NH<sub>3</sub>)<sub>5</sub>(MIO)]<sup>3+</sup>, [Pt<sup>II</sup>Cl<sub>3</sub>(MIO)]<sup>−</sup>, and <i>trans</i>-[U<sup>VI</sup>O<sub>2</sub>(NO<sub>3</sub>)<sub>2</sub>(MIO)<sub>2</sub>], 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 (p<i>K</i><sub>a</sub>) and
donor number (DN) for the oxygen atom of MIO and Lever’s electrochemical
parameter (<i>E</i><sub>L</sub>) and a relative covalency
parameter (<i>k</i><sub>L</sub>) for the sulfur atom.