Mono-, Di-, and Tricarboxylic Acids:  Central Building Blocks for the Formation of Multinuclear Transition Metal Complexes

Abstract

The synthesis and characterization of the di-, tetra-, and hexanuclear titanium(IV)-copper-(I) carboxylates {[Ti](CtCSiMe 3 ) 2 }CuO 2 CR 2 (3) {3a: R 2 ) Me, 3b: R 2 ) C 6 H 5 , 3c: R 2 ) CH 2 C 6 H 5 , 3d: R 2 ) CHdCMe 18) is described. All of these complexes are easily accessible by the reaction of {[Ti](CtCR 1 ) 2 }CuMe (1a: R 1 ) SiMe 3 , 1b: R 1 ) t Bu) with the corresponding carboxylic acids in different stoichiometric ratios of the reactants. Furthermore, the preparation and reaction chemistry of the alkyne-stabilized copper(I) percarboxylate 10) is discussed. As the central organic building block, all complexes contain mono-, di-, or tricarboxylic units. The latter two allow for the subsequent addition of further titanium(IV)-copper(I) assemblies onto these entities. The X-ray structure analyses of 3a and 13a are reported. Within the {[Ti](CtCR 1 ) 2 }CuOC(O)R 2 array the copper(I) center is η 2 -coordinated by both R 1 CtC groups of the organometallic tweezer [Ti](CtCR 1 ) 2 and η 1 -bonded by one oxygen atom of the O 2 CR 2 unit. Cyclic voltammetric studies on representative examples are presented and discussed comparatively.

Heterotrimetallic M−M′−M′′ Transition Metal Complexes Based on 1,3,5-Triethynylbenzene: Synthesis, Solid State Structure, and Electrochemical and UV−Vis Characterization. EPR Analysis of thein SituGenerated Associated Radical Cations

“…The synthesis of organometallic π-tweezer-based copper (I) acetylides is possible by the reaction of [{[Ti](μ-σ,π-CCSiMe 3 ) 2 }CuCH 3 ] ([Ti] = (η 5 -C 5 H 4 SiMe 3 ) 2 Ti) with CH-acidic alkynes . Nevertheless, attempts to obtain 1-(FcCC)-3-[( t Bu 2 bpy)(CO) 3 ReCC]-5-[{[Ti](μ-σ,π-CCSiMe 3 ) 2 }CuCC]C 6 H 3 by reacting 8 with [{[Ti](μ-σ,π-CCSiMe 3 ) 2 }CuCH 3 ] in tetrahydrofuran at room temperature failed, presumably due to the steric bulkiness of the bis(alkynyl)titanocene and the [( t Bu 2 bpy)(CO) 3 Re] fragments.…”

μ-Oxalato-bis[bis(triphenylphosphine)copper(I)] dichloromethane disolvate

“…For a comprehensive patent covering CVD applications of copper(I) oxalates, see: Kö hler & Meyer (2004). For related copper(I) oxalate complexes, see: Frosch et al (2000); He et al (2008); Teichgrä ber et al (2005). For the chemical fixation of CO 2 to form oxalates, see: Savé ant (2008).…”

Copper(I) oxalate complexes: Synthesis, structures and surprises

“…Another early example of a copper(I) oxalate complex was a dinuclear triphenylphosphine complex reported by Gimeno et al [7], structurally characterized later by the Lang group [8], which also reported a few other copper(I) oxalate phosphine complexes in the same paper. Lang et al also reported a copper(I) oxalate complex with a bis(trimethylsilylpentadienyl)titanium bis(trimethylsilylacetylide) tweezer ligand, but the complex was not structurally characterized [9]. In a couple of seminal studies by Meyer, Köhler, and coworkers [1,2], a series of copper(I) oxalate complexes with alkyne, alkene and isocyanide ligands were synthesized, a number of which were structurally characterized, not including alkene complexes.…”