Novel oxorhenium complexes with 2-(2′-hydroxyphenyl)-2-benzothiazolinato ligand: X-ray studies, spectroscopic characterization and DFT calculations

The [ReOX2(hbt)(EPh3)] (X = Cl, Br; E = As, P) chelates have been prepared in the reactions of [ReOX3(EPh3)2] complexes (X = Cl, Br; E = P, As) with 2-(2′-hydroxyphenyl)-2-benzothiazole (hbtH) in acetone. From the reactions of [ReOX3(PPh3)2] with hbtH two kind of crystals [ReOX2(hbt)(PPh3)] · MeCN and [ReOX2(hbt)(PPh3)] with different arrangement of halide ions (cis and trans) were isolated, whereas the [ReOX3(AsPh3)2] oxocompounds react with hbtH to give only cis-halide isomers. The complexes were structurally and spectroscopically characterised. The electronic structures of both [ReOBr2(hbt)(PPh3)] isomers have been calculated with the density functional theory (DFT) method. The TDDFT/PCM calculations have been employed to produce a hundred of singlet excited-states starting from the ground-state geometry optimized in the gas phase of cis- and trans-halide isomers of [ReOBr2(hbt)(PPh3)] and the UV–Vis spectra of these complexes have been discussed on this basis.

Graphical abstractThe [ReOX2(hbt)(EPh3)] (XCl, Br; EAs, P) chelates have been prepared in the reactions of [ReOX3(EPh3)2] complexes (XCl, Br; EP, As) with 2-(2’-hydroxyphenyl)-2-benzothiazole (hbtH) in acetone. From the reactions of [ReOX3(PPh3)2] with hbtH two kind of crystals [ReOX2(hbt)(PPh3)] · MeCN and [ReOX2(hbt)(PPh3)] with different arrangement of halide ions (cis and trans) were isolated, whereas the [ReOX3(AsPh3)2] oxocompounds react with hbtH to give only cis-halide isomers. The complexes were structurally and spectroscopically characterised. The electronic structures of both [ReOBr2(hbt)(PPh3)] isomers have been calculated with the density functional theory (DFT) method. The TDDFT/PCM calculations have been employed to produce a hundred of singlet excited-states starting from the ground-state geometry optimized in the gas phase of cis- and trans-halide isomers of [ReOBr2(hbt)(PPh3)] and the UV-Vis spectra of these complexes have been discussed on this basis.Figure optionsDownload full-size imageDownload as PowerPoint slide