Stabilization of a W26+ bimetallic complex supported by two N,N′,N″-triphenylguanidinate ligands

•Synthesis of W26+ bimetallic complex supported by two triphenylguanidinate ligands.•Structural characterization by X-ray crystallography, NMR and Raman spectroscopies.•Description of the electronic structure by electrochemistry and DFT calculations.•EPR and Raman spectroscopies performed on the one electron reduction product.

The triple bonded compound W2(TPG)2Cl4, 1, where TPG is the anion of N,N′,N″-triphenylguanidine, was synthesized and structurally characterized by single-crystal X-ray crystallography, FT-IR, NMR and Raman spectroscopies, and electrochemical methods. The W–W distance of 1 in the solid state is 2.2604(4) Å, and the compound shows two one-electron reversible reductions at (E1/2) −0.95, and −2.31 V (versus FeCp2/FeCp2+). The one-electron reduction of 1 yields 2, which was characterized by Raman and EPR spectroscopies (g = 1.83). The Raman shift of the W–W bond of 1 and 2 are, 290 and 315 cm−1, respectively, consistent to the increase in bond order. DFT calculations were performed on 1 and 2 to aid in the assignment of the Raman shifts, and to help understand their electronic properties.

Graphical abstractWe report the synthesis and structural characterization of a triply bonded ditungsten, W26+, 1, complex supported by two N,N′,N″-triphenylguanidinate ligands (W–W bond distance 2.2604(4) Å). We study the electrochemistry, Raman, and electronic structure properties of 1, and describe our efforts to synthesize a W25+ complex.Figure optionsDownload full-size imageDownload as PowerPoint slide