The crystal structure of a new double hydroxyethyl-bridged dizinc(II) complex with macrocyclic ligand

A new dizinc(II) complex with 6,20-bis(2-hydroxyethyl)-3,6,9,17,20,23-hexaaza-tricyclo [23,3,1,111,15]-triaconta-1(29),11(30),12,14,25,27-hexaene (L) was synthesized and characterized. The crystal structure of [Zn2H−2L](ClO4)2 has indicated that both Zn2+ ions are in penta-coordination environment with distorted trigonal bipyramid consisting of three N atoms from diethylenetriamine moieties, one internal O atom of the hydroxyethyl pendant, one intermolar O atom from another hydroxyethyl pendant, and the separation of Zn⋯Zn is 3.05 Å. The two aromatic rings are parallel to each other, with the centroid–centroid distance 9.21 Å. ES–MS spectra showed the main species of [Zn2H−2L]2+, [Zn2H−2L(H2O)2]2+, and [Zn2H−2L(ClO4)]+. The hydrolysis of 4-nitrophenyl acetate catalyzed by [Zn2H−2L]2+ in 10% (v/v) CH3CN at 25 °C, with I=0.10 (NaNO3) and pH 9.0, has shown a second-order rate constant of 0.021 M−1s−1.