Dinuclear Complexes with Bis(benzenedithiolate) Ligands

Abstract

As a part of a broader study directed towards helical coordination compounds with benzenedithiolate donors, we have synthesized the bis(benzenedithiol) ligands 1,2‐bis(2,3‐dimercaptobenzamido)ethane (H4‐1) and 1,2‐bis(2,3‐dimercaptophenyl)ethane (H4‐2). Both ligands form dinuclear complexes with NiII, NiIII and, after air‐oxidation, CoIII ions under equilibrium conditions. Complexes (NEt4)4[NiII2(1)2] (11 b), (NEt4)2[NiIII2(1)2] (13), and Na4[NiII2(2)2] (14) were characterized by X‐ray diffraction. In all complexes, two square‐planar [Ni(S2C6H3R)2] units are linked in a double‐stranded fashion by the carbon backbone and they assume a coplanar arrangement in a stairlike manner. Cyclic voltammetric investigations show a strong dependence of the redox potential on the type of the ligand. The substitution of 14− for 24− on nickel (−785 mV for 11 b versus −1130 mV for 14, relative to ferrocene) affects the redox potential to a similar degree as the substitution of nickel for cobalt (−1160 mV for [Co2(1)2]2−/[Co2(1)2]4−, relative to ferrocene). The redox waves display a markedly less reversible behavior for complexes with the shorter bridged ligand 24− compared to those of 14−.

Synthesis and X-ray Molecular Structure of [WVI(C6H4S2-1,2)3] Completing the Structural Characterization of the Series [W(C6H4S2-1,2)3]n (n = 0, 1, 2): Trigonal-Prismatic versus Octahedral Coordination in Tris(benzene-1,2-dithiolato) Complexes

“…In connection with our research on helicates with benzene-1,2-dithiolato ligands [13] we investigated methods for the preparation of [W VI (C 6 H 4 S 2 -1,2) 3 ]. Published syntheses of tris(benzene-1,2-dithiolato) transition metal complexes [2d] involve the reaction of metal halides with an excess of benzene-1,2-dithiol in CCl 4 with liberation of gaseous HCl.…”

Synthesis and Coordination Chemistry of a Tris(benzene-o-dithiolato)- functionalized Ligand as a Siderophore Analog

“…NMR spectra were recorded on Bruker Avance II and Avance III spectrometers. Mass spectra were obtained with a [25,26] have been prepared according to published procedures.…”

“…1,3,5-Tris(aminomethyl)-2,4,6-triethylbenzene 3 was prepared from 2 using a protocol described previously [24]. The triamine 3 reacts with 4, which was obtained by chlorination of 2,3-di(isopropylmercapto)benzoic acid [25,26] with oxalyl chloride to give the ligand precursor (iPr) 6 -5. Cleavage of the S-isopropyl bonds in (iPr) 6 4 ] in the presence of Na 2 CO 3 as a base in methanol resulted in a deep-red color of the solution (λ max = 534 nm), which is typical of the {TiS 6 } 2− chromophore (Scheme 2) [27].…”

Ein zweikerniges, dreisträngiges Helicat mit einem Diamid‐verbrückten Brenzcatechin/ Benzoldithiol‐Liganden

“…Besonderes Interesse galt dabei dreisträngigen Helicaten mit Brenzcatechinato‐Donorgruppen;2 über Helicate mit Thiolato‐Donorgruppen ist dagegen weit weniger bekannt. Nur über einige Bis(benzoldithiol)‐Liganden3 und ihre zweikernigen Nickel‐Komplexe wurde berichtet 4. Wir präsentieren hier die Synthese eines Brenzcatechin/Benzoldithiol(O‐O/S‐S)‐Liganden (H 4 ‐ 1 ) und die Molekülstruktur des dreisträngigen Λ,Λ‐Helicats Na(PNP) 3 [Ti 2 ( 1 ) 3 ] (PNP + =Bis(triphenylphosphoranyliden)ammonium)…”