Seven-coordinate rhenium(III) complexes of 1-(2-pyridylazo)-2-naphtholate: X-ray studies, spectroscopic characterization and DFT calculations

The reactions of [ReX3(MeCN)(PPh3)2] (X = Cl or Br) with 1-(2-pyridylazo)-2-naphthol (HPAN) have been examined and the [ReBr(PAN)2] · 2CHCl3 (1) and [ReCl(PAN)2] (2) complexes have been obtained. The both complexes have been structurally and spectroscopically characterized, and compound 1 has been additionally studied by magnetic measurements. The magnetic behavior is characteristic of mononuclear seven-coordinated Re(III) complex with d4 low-spin configuration, which gives diamagnetic ground state.The electronic structure of [ReBr(PAN)2] has been calculated with the density functional theory (DFT) method. The time-dependent DFT calculations have been employed to calculate the electronic spectrum of [ReBr(PAN)2], and the UV–Vis spectra of the [ReX(PAN)2] compounds have been discussed on this basis.

Graphical abstractThe reactions of [ReX3(MeCN)(PPh3)2] (X = Cl or Br) with 1-(2-pyridylazo)-2-naphthol (HPAN) have been examined and the [ReBr(PAN)2]·2CHCl3 (1) and [ReCl(PAN)2] (2) complexes have been obtained. The both complexes have been structurally and spectroscopically characterized, and compound 1 has been additionally studied by magnetic measurements. The magnetic behavior is characteristic of mononuclear seven-coordinated Re(III) complex with d4 low-spin configuration, which gives diamagnetic ground state. The electronic structure of [ReBr(PAN)2] has been calculated with the density functional theory (DFT) method. The time-dependent DFT calculations have been employed to calculate the electronic spectrum of [ReBr(PAN)2], and the UV–Vis spectra of the [ReX(PAN)2] compounds have been discussed on this basis.Figure optionsDownload full-size imageDownload as PowerPoint slide