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.

We 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 as PowerPoint slide