Guanidino‐Functionalised Aromatic Electron Donors at Work: Competing Hydrogen‐ and Electron‐Transfer Reactions in the Course of the Synthesis of Gold Acetylide Complexes

Abstract

In this work reactions between [AuCl(PPh 3 )] and HCϵCAr (Ar = phenyl, pyridinyl, biphenyl or p-acetylphenyl) in the presence of the nitrogen base and organic electron donor 1,2,4,5-tetrakis(N,NЈ-dimethyl-N,NЈ-ethyleneguanidino)benzene (1) were studied. Two different product types were isolated and characterised: the neutral Au

Air‐Stable, Dinuclear and Tetranuclear σ,π‐Acetylide Gold(I) Complexes and Their Catalytic Implications

“…Both Au I intermediates were isolated as pure crystals suitable for X‐ray crystal structure analysis (see Figures S12 and S13 and Tables S3 and S4 in the Supporting Information for atom coordinates). Crystals of neutral [Au(PPh 3 )(phenylethynyl)] ( 8 ) have already been obtained47, 48 by a different synthetic method and the crystal structure has been determined previously. However, our analysis of the new X‐ray diffraction data for the gold compound ( 8 ; crystallized from toluene) resulted in significantly different unit‐cell parameters.…”

“…As can be seen in Scheme 3, the solid was formed from a mixture of neutral dicoordinate Au I complex 8, with triphenylphosphine and phenylacetylide ligands coordinated through a s bond, and complex 9, which corresponds to a cationic Au I complex with two triphenylphosphine ligands with a bistrifluromethylsulphonylamide counteranion. Both Au I intermediates were isolated as pure crystals suitable for X-ray crystal structure analysis (see Figures S12 and S13 and Tables S3 [47,48] by a different synthetic method and the crystal structure has been determined previously. However, our analysis of the new X-ray diffraction data for the gold compound (8; crystallized from toluene) resulted in significantly different unit-cell parameters.…”

Guanidine Electron Donors and Silver Halides: Interplay and Competition between Redox, Coordination and Polymerization Reactions

“…In addition, a weak and broad feature occurs at 589 (614) nm (see inset in Figure 1). Single crystals of (1)Cl 2 and (1)Br 2 ·4MeOH suitable for XRD were obtained from CH 3 ) for (1)Cl 2 : N1-C1 129.9(2), N1-C7 137.0(2), N2-C7 133.4(3), N3-C7 134.0(3), N4-C2 133.8(2), N4-C12 134.8(2), N5-C12 133.9(2), N6-C12 134.9(2), N7-C4 130.3(2), N7-C17 136.4(2), N8-C17 135.0(2), N9-C17 132.9(2), N10-C5 134.7(2), N10-C22 134.6(2), N11-C22 135.1(2), N12-C22 134.2(2), C1-C2 150.2(2), C1-C6 141.6(2), C2-C3 137.6(2), C3-C4 142.2(2), C4-C5 150.6(2), C5-C6 137.2(2); C1-N1-C7 129.44 (15), C2-N4-C12 122.79(14), C4-N7-C17 125.48 (15), C5-N10-C22 122.59(14), N2-C7-N3 121.09 (17), N5-C12-N6 118.74 (16), N8-C17-N9 121.17 (15), N11-C22-N12 118.68 (15). Selected structural parameters (bond lengths [pm], bond angles [°]) for (1)Br 2 : N1-C1 135.17 (19), N1-C4 133.97 (19), N2-C4 135.26 (19), N3-C4 134.75 (19), N4-C2 130.64 (19), N4-C9 136.94 (19), N5-C9 134.30 (19), N6-C9 132.65 (19), C1-C2 149.9(2), C1-C3 137.3(2), C2-C3Ј 141.8(2); C1-N1-C4 122.58 (13), N2-C4-N3 117.96(13), C2-N4-C9 125.54(13), N5-C9-N6 121.13 (13).…”

“…One example is provided by the treatment of a solution of 2 with [AuCl(PPh 3 )] and PhCCH in CH 3 CN. [16] In this case, the redox channel that leads to the salt 2[Au(CCPh) 2 ] 2 and the Brønsted acid-base channel that leads to the neutral Au complex [Au(PPh 3 )CCPh] exhibit similar kinetics in CH 3 CN. Consequently, a roughly equimolar mixture of both product types results.…”

One‐ versus Two‐Electron Oxidation of Complexed Guanidino‐Functionalized Aromatic Compounds

“…[13,14] In recent years we synthesized several dinuclear copper complexes of 1 in which different oxidation states of copper and the guanidine ligand are realized, and established an almost complete electron-transfer series (some examples are given below). [13,14] In recent years we synthesized several dinuclear copper complexes of 1 in which different oxidation states of copper and the guanidine ligand are realized, and established an almost complete electron-transfer series (some examples are given below).…”