A novel bismercury(II) complex of bidentate N21,N22-bridged porphyrin: [((benzamido-κN)phenylmercury-κHg–N21,N22)-meso-tetraphenylporphyrinato-N23,N24]phenylmercury(II) toluene solvate

Reaction of PhHgOAc with N-NHCOC6H5–Htpp gave a bismercury(II) complex [((benzamido-κN)phenylmercury-κHg–N21,N22)-meso-tetraphenylporphyrinato-N23,N24]phenylmercury(II) toluene solvate [Hg(Ph)(N21,N22–(Ph)–Hg–N(COPh)tpp · C6H5CH3; 3 · C6H5CH3] with Hg(1)–N(5) as N21,N22-bridged atoms. The crystal structure of 3 · C6H5CH3 was determined. The Hg(1)⋯Hg(2) distance is 3.611(7) Å. Hence, no metallophilic Hg(II)⋯Hg(II) interaction is present. 3 in CDCl3 was characterized by 1H, 13C, and 199Hg NMR. The 199Hg NMR spectrum for 3 in CDCl3 solution 20 °C clearly reveals that there are two different Hg nuclei, i.e. Hg(1) and Hg(2) and this NMR data provides an evidence that 3 remains as a bismercury species in CDCl3 solution. The 199Hg NMR spectrum for a 0.2 M solution of 3 in CDCl3 at 20 °C is observed at −1088 ppm for Hg(2) nucleus with 3J(Hg–H) = 188 Hz and an effective coordination number of five and at −1119 ppm for Hg(1) nucleus with 3J(Hg–H) = 177 Hz and an effective coordination number of four. The proton and 199Hg NMR spectra clearly show 3J(Hg–H) coupling and these NMR data indicate no ligand exchange for 3 in CDCl3.

Graphical abstractWe have investigated one new diamagnetic porphyrin complex, namely, dinuclear mercury(II) complex of 3 · C6H5CH3 and its X-ray structure is established. 3 · C6H5CH3 is a new class of bismercury porphyrin complex with Hg(1)–N(5) bidentately coordinated to N21,N22-porphyrin and with Hg(2) as metal bridge.Figure optionsDownload full-size imageDownload as PowerPoint slide