Nickel(II) and Palladium(II) Thiaethyneporphyrins. Intramolecular Metal(II)−η²-CC Interaction inside a Porphyrinoid Frame

3,18-Diphenyl-8,13-di-<i>p</i>-tolyl-20-thiaethyneporphyrin ([18]­thiatriphyrin­(4.1.1)), which formally contains an C1–C2 ethyne moiety instead of pyrrole embedded in the macrocyclic framework of 21-thiaporphyrin, was obtained in a modification of the “3 + 1” approach using the ethyne analogue of tripyrrane (1,4-diphenyl-1,4-di(pyrrol-2-yl)but-2-yne) and 2,5-bis­(<i>p</i>-tolylhydroxymethyl)­thiophene. The spectroscopic and structural properties of 20-thiaethyneporphyrin reflect its macrocyclic aromaticity, revealing a combination of the acetylene (≥C–CC–C≤) and cumulene (>CCCC<) character of the C18–C1–C2–C3 linker. The magnetic manifestations of aromaticity and antiaromaticity of thiaethyneporphyrin and its two-electron-oxidized derivative were observed using ¹H NMR spectroscopy and were confirmed by density functional theory calculations involving chemical shifts and nucleus-independent chemical shift analysis. Protonation of 20-thiaethyneporphyrin yielded a nonaromatic tautomer of <i>iso</i>-20-thiaethyneporphyrin, locating the saturated meso carbon adjacent to thiophene. Insertion of palladium­(II) and nickel­(II) into 20-thiaethyneporphyrin afforded planar palladium­(II) thiaethyneporphyrin and low-spin diamagnetic nickel­(II) 20-thiaethyneporphyrin as determined by X-ray crystallography. 20-Thiaethyneporphyrin acts as a dianionic ligand that coordinates through the two nitrogen and one sulfur donors. Metal­(II) ions are uniquely exposed to form an intramolecular metal­(II)−η²-CC bond, whereas the organometallic fragment is coplanar with the whole macrocycle. Coordination of pyridine converts diamagnetic nickel­(II) thiaethyneporphyrin into its paramagnetic counterpart as determined by ¹H NMR

Copper(II) Thiaethyneporphyrin and Copper(II) 21-Phosphoryl N‑confused Porphyrin Hybrids. Intramolecular Copper(II)–Carbon Interaction Inside of a Porphyrinoid Surrounding

Stabilization of unusual organocopper­(II) species via the very efficient protection of the copper­(II)–carbon bond has been achieved encapsulating the copper­(II) center in the coordination core of suitably constructed carbaporphyrinoids. Copper­(II) was inserted into hybrid N-confused porphyrins which contain 21-diphenylphosphoryl-, 21-diphenylthiophosphoryl-, or 21-phosphinodithioic substituents or into 20-thiaethyneporphyrin, an aromatic porphyrinoid, which combines two structural motifs of 21-thiaporphyrin and ethyne. Two distinctly different types of the copper­(II)–carbon bond have been detected. Copper­(II) hybrid N-confused porphyrins reveal the η¹-C­(21) side-on coordination. The unprecedented equatorial metal­(II)···η²-CC interaction has been trapped in a copper­(II) thiaethyneporphyrin surrounding

Copper(II) Thiaethyneporphyrin and Copper(II) 21-Phosphoryl N‑confused Porphyrin Hybrids. Intramolecular Copper(II)–Carbon Interaction Inside of a Porphyrinoid Surrounding

Stabilization of unusual organocopper­(II) species via the very efficient protection of the copper­(II)–carbon bond has been achieved encapsulating the copper­(II) center in the coordination core of suitably constructed carbaporphyrinoids. Copper­(II) was inserted into hybrid N-confused porphyrins which contain 21-diphenylphosphoryl-, 21-diphenylthiophosphoryl-, or 21-phosphinodithioic substituents or into 20-thiaethyneporphyrin, an aromatic porphyrinoid, which combines two structural motifs of 21-thiaporphyrin and ethyne. Two distinctly different types of the copper­(II)–carbon bond have been detected. Copper­(II) hybrid N-confused porphyrins reveal the η¹-C­(21) side-on coordination. The unprecedented equatorial metal­(II)···η²-CC interaction has been trapped in a copper­(II) thiaethyneporphyrin surrounding

Nickel(II) and Palladium(II) Thiaethyneporphyrins. Intramolecular Metal(II)−η²-CC Interaction inside a Porphyrinoid Frame

3,18-Diphenyl-8,13-di-<i>p</i>-tolyl-20-thiaethyneporphyrin ([18]­thiatriphyrin­(4.1.1)), which formally contains an C1–C2 ethyne moiety instead of pyrrole embedded in the macrocyclic framework of 21-thiaporphyrin, was obtained in a modification of the “3 + 1” approach using the ethyne analogue of tripyrrane (1,4-diphenyl-1,4-di(pyrrol-2-yl)but-2-yne) and 2,5-bis­(<i>p</i>-tolylhydroxymethyl)­thiophene. The spectroscopic and structural properties of 20-thiaethyneporphyrin reflect its macrocyclic aromaticity, revealing a combination of the acetylene (≥C–CC–C≤) and cumulene (>CCCC<) character of the C18–C1–C2–C3 linker. The magnetic manifestations of aromaticity and antiaromaticity of thiaethyneporphyrin and its two-electron-oxidized derivative were observed using ¹H NMR spectroscopy and were confirmed by density functional theory calculations involving chemical shifts and nucleus-independent chemical shift analysis. Protonation of 20-thiaethyneporphyrin yielded a nonaromatic tautomer of <i>iso</i>-20-thiaethyneporphyrin, locating the saturated meso carbon adjacent to thiophene. Insertion of palladium­(II) and nickel­(II) into 20-thiaethyneporphyrin afforded planar palladium­(II) thiaethyneporphyrin and low-spin diamagnetic nickel­(II) 20-thiaethyneporphyrin as determined by X-ray crystallography. 20-Thiaethyneporphyrin acts as a dianionic ligand that coordinates through the two nitrogen and one sulfur donors. Metal­(II) ions are uniquely exposed to form an intramolecular metal­(II)−η²-CC bond, whereas the organometallic fragment is coplanar with the whole macrocycle. Coordination of pyridine converts diamagnetic nickel­(II) thiaethyneporphyrin into its paramagnetic counterpart as determined by ¹H NMR