Details

Autor(en) / Beteiligte

• Rottschäfer, Dennis
• Neumann, Beate
• Stammler, Hans‐Georg
• Sergeieva, Tetiana
• Andrada, Diego M.
• Ghadwal, Rajendra S.

Titel

Isolation of a 16π‐Electrons 1,4‐Diphosphinine‐1,4‐diide with a Planar C4P2 Ring

Ist Teil von

• Chemistry : a European journal, 2021-02, Vol.27 (9), p.3055-3064

Ort / Verlag

Weinheim: Wiley Subscription Services, Inc

Erscheinungsjahr

2021

Link zum Volltext

Quelle

Wiley Blackwell Single Titles

Beschreibungen/Notizen

• Herein, we report the first 1,4‐diphosphinine‐1,4‐diide compound [(ADCPh)P]2 (5‐Ph) (ADCPh=PhC{(NDipp)C}2; Dipp=2,6‐iPr2C6H3) derived from an anionic dicarbene (ADCPh) as a red crystalline solid. Compound 5‐Ph containing a 16π‐electron planar fused‐tricyclic ring system was obtained by the 4e reduction of [(ADCPh)PCl2]2 (4‐Ph) with Mg (or KC8) in a quantitative yield. Experimental and computational results imply that the central 8π‐electrons C4P2 ring of 5‐Ph, which is fused between two 6π‐electrons C3N2 aromatic rings, is antiaromatic. Thus, each of the phosphorus atoms of 5‐Ph has two electron‐lone‐pairs, one in a p‐type orbital is in conjugation with the C=C bonds of the C4P2 ring, while the second resides in a σ‐symmetric orbital. This can be shown with the gold complex [(ADCPh)P(AuCl)2]2 (6‐Ph) obtained by reacting 5‐Ph with (Me2S)AuCl. A mixture of 5‐Ph and 4‐Ph undergoes comproportionation in the presence of MgCl2 to form the intermediate oxidation state compound [(ADCAr)P]2(MgCl4) (7‐Ph), which is an aromatic species. Aromatic (I) and antiaromatic (II) C4P2 ring systems derived from an anionic dicarbene (ADC) have been reported. Electronic structures of I and II have been analyzed by NMR and X‐ray diffraction studies and corroborated by computational calculations. The ACID (anisotropy of induced current density) plot of II shows that the ring current in the central C4P2 ring is paratropic (antiaromatic) whereas the peripheral C3N2 rings exhibit two local diatropic ring currents. The ACID plot of the aromatic system II unveils a global diatropic current on the periphery of the C3N2 and C4P2 rings.