Binucleating Aza‐Sulfonate and Aza‐Sulfinate Macrocycles — Synthesis and Coordination Chemistry

Abstract

The preparation and ligating properties of S-oxygenated derivatives of a macrobinucleating hexaazadithiophenolate macrocycle H 2 L 1 of the Robson type towards nickel(II) and zinc(II) ions are reported. Nickel complexes of the hexaazadi-

Chemistry of metalated container molecules

“…The shift to higher field can be explained by the ring current effect. The coligands are located above the center of the two aryl rings of (L 2 ) 2À in the shielding region [57]. This results in the observed chemical shift change to higher field.…”

“…This is mainly due to two factors: (i) the decrease in the ligand field strength and (ii) the increase in the steric requirements upon going from a secondary to a tertiary amine donor function [55]. In order to examine whether the properties of our complexes are affected by the N-alkyl substituents, we have characterized analogous complexes of the two macrocycles H 2 L 1 and H 2 L 2 by various spectroscopic methods (IR, UV/Vis, EPR, 57 Fe-M€ ossbauer spectroscopy), cyclic voltammetry, temperature-dependent magnetic susceptibility measurements and X-ray crystallography. The most important findings of these investigations are as follows:…”

Preparation and Characterization of Dinuclear Nickel(II) Complexes Containing N3Ni(μ1, 3‐SO3R)2(μ‐RCN4)NiN3 Cores: Crystal Structures and Magnetic Properties

“…[9][10][11] In previous work, we always used the perchlorate salts in such oxidation reactions. [7] We now found that this method works for the tetraphenylborate salts as well. …”

“…Analogous pairs of dinuclear [Ni 2 (L1)(LЈ)] + and [Ni 2 (L2)(LЈ)] + complexes have been reported with LЈ = Cl -, CH 3 CO 2 -, PhCO 2 -, 3-Cl-C 6 H 4 CO 2 -. [7,8] It was found that the structures and chemical properties are strikingly different, a fact attributable to the conversion of the cases converted to μ 1,3 -bridging sulfonate groups to generate N 3 Ni(μ 1,3 -SO 3 R) 2 Upon oxidation the magnetic properties are affected. In contrast to 1-3, which exhibit an intramolecular ferromagnetic exchange interaction (S = 2 ground state), the spins of the nickel(II) (S i = 1) ions in 4-6 are antiferromagnetically coupled, the coupling constants J being -1.39 cm -1 (4), -1.43 cm -1 (5), and -1.60 cm -1 (6) (H = -2JS 1 S 2 ) to yield a diamagnetic S = 0 ground state.…”

“…1200 cm -1 , which are attributable to the S-O 3 -groups in 4-6 are also in a μ 1,3 -bridging mode. [7,8] UV/Vis spectroscopic data of 4-6 were recorded from 190-1600 nm in acetonitrile solution at room temperature with a Jasco V-670 UV/Vis/NIR spectrophotometer. The most obvious spectral differences among the thiophenolate and phenylsulfonate complexes occur in the UV/Vis region around 400 nm.…”