Die dreikernigen Kupfer(I)‐Thiolat‐Komplexe [Cu₃(NGuaS)₃]^0/1+ und ihre dimeren Varianten [Cu₆(NGuaS)₆]^1+/2+/3+ mit biomimetischen Redoxeigenschaften

Abstract

Ein redoxaktiver gemischtvalenter Kupfer‐Thiolat‐Komplex entsteht bei der Reaktion von [Cu(MeCN)4]PF6 mit einem CPh3‐Thioether durch ein Zusammenwirken von homo‐ und heterolytischer Spaltung der S‐CPh3‐Bindung. Die Metallatome in dem sechskernigen Kupfer‐Schwefel‐Cluster (siehe Bild) haben im oxidierten Zustand dieselbe mittlere Oxidationsstufe wie im zweikernigen Kupfer‐Thiolat‐Zentrum (CuA) von Cytochrom‐c‐Oxidase und N2O‐Reduktase.

A Halide‐Induced Copper(I) Disulfide/Copper(II) Thiolate Interconversion

“…During studies on the influence of polyfunctional ligands containing guanidine‐ and sulfur‐donor functions on the structural and electrochemical properties of copper complexes we were recently able to isolate the disulfide 2′,2′‐(2,2′‐dithiodiphenyl)bis(1,1,3,3‐tetramethylguanidine) (NGuaSSGuaN or (NGuaS‐) 2 ) 3k. 7 Reaction of [Cu(MeCN) 4 ]OTf with a yellow suspension of (NGuaS‐) 2 (ratio 1:1) in acetonitrile resulted in a deep red solution, from which, after filtration and subsequent treatment with diethyl ether, red crystals of [Cu I 2 {(NGuaS‐) 2 } 2 ][OTf] 2 ( 1 [OTf] 2 ; Scheme , route A) separated in the course of one week.…”

“…We attribute this behavior to the strong folding of the Cu 2 S 2 diamond, as all mixed‐valence copper complexes known to date have planar frames 2. 3h,k, 11…”

“…1 [OTf] 2 : The reaction of (NGuaS‐) 2 3k, 7 (1.1 mmol, 444 mg) and [Cu(MeCN) 4 ]OTf13 (1 mmol, 376 mg) in MeCN (10 mL) leads to a suspension of a red solid. The reaction mixture was stirred for 1 h at room temperature.…”

[Cu6(NGuaS)6]2+ and its oxidized and reduced derivatives: Confining electrons on a torus

“…The complex is, as described in Refs. composed of two Cu 3 S 3 rings which are on top of each other and shifted by one atom so that a S atom is on top of a Cu atom. These two rings form a cylindrical hexagon (compare Fig.…”

Density functional theory of the CuA‐like Cu2S2 diamond core in Cu (NGuaS)2Cl2

“…[27] It has been shown that type-1 centers can be structurally converted into purple Cu A centers. [29][30][31][32][33][34][35][36][37][38][39][40] The first, though not reversibly reducible, mixed-valent complex has been developed by Tolman and coworkers [41] and theoretically characterized by Solomon et al [42] Duboc and coworkers succeeded in synthesizing a mixed-valent thiolate bridged complex, showing biomimetic functionality. [29][30][31][32][33][34][35][36][37][38][39][40] The first, though not reversibly reducible, mixed-valent complex has been developed by Tolman and coworkers [41] and theoretically characterized by Solomon et al [42] Duboc and coworkers succeeded in synthesizing a mixed-valent thiolate bridged complex, showing biomimetic functionality.…”