Heterodinuclear Metal Arrangement in a Flat Macrocycle with Two Chemically- Equivalent Metal Chelating Sites
journal contribution
posted on 2012-02-06, 00:00 authored by Masumi Kuritani, Shohei Tashiro, Mitsuhiko ShionoyaA phenanthroline-based macrocycle <b>1</b> has
been newly
developed which has two chemically equivalent metal chelating sites
within the spatially restricted cavity for dinuclear metal arrangement.
The macrocycle <b>1</b> reacts with Zn(CF<sub>3</sub>CO<sub>2</sub>)<sub>2</sub> or ZnCl<sub>2</sub> to form homodinuclear Zn(II)-complexes.
A single-crystal X-ray structural analysis of the resulting Zn<sub>2</sub><b>1</b>(CF<sub>3</sub>CO<sub>2</sub>)<sub>4</sub> determined
the complex structure in which two Zn(II) ions are bound by two phenanthroline
sites and two CF<sub>3</sub>CO<sub>2</sub><sup>–</sup> ions
bind to each Zn(II) ion in a tetrahedral geometry. Similarly, a homodinuclear
Cu(I)-macrocycle was formed from <b>1</b> and Cu(CH<sub>3</sub>CN)<sub>4</sub>BF<sub>4</sub>. Notably, from <b>1</b> and an
equimolar mixture of Cu(CH<sub>3</sub>CN)<sub>4</sub>BF<sub>4</sub> and Zn(CF<sub>3</sub>CO<sub>2</sub>)<sub>2</sub>, a heterodinuclear
Cu(I)–Zn(II)-macrocycle was exclusively formed in high yield
(>90%) because of the relatively low stability of the dinuclear
Cu(I)-macrocycle.
A heterodinuclear Ag(I)–Zn(II)-macrocycle was similarly formed
with fairly high selectivity from a mixture of Ag(I) and Zn(II) ions.
Such selective heterodinuclear metal arrangement was not observed
with other combinations of M-Zn(II) (M = Li(I), Mg(II), Pd(II), Hg(II),
La(III), and Tb(III)).
