Details

Autor(en) / Beteiligte

• Miesel, Dominique
• Hildebrandt, Alexander
• Korb, Marcus
• Wild, Duncan A.
• Low, Paul J.
• Lang, Heinrich

Titel

Influence of P-Bonded Bulky Substituents on Electronic Interactions in Ferrocenyl-Substituted Phospholes

Ist Teil von

• Chemistry : a European journal, 2015-08, Vol.21 (32), p.11545-11559

Ort / Verlag

Weinheim: WILEY-VCH Verlag

Erscheinungsjahr

2015

Quelle

Wiley Blackwell Single Titles

Beschreibungen/Notizen

• 2,5‐Diferrocenyl‐1‐Ar‐1H‐phospholes 3 a–e (Ar=phenyl (a), ferrocenyl (b), mesityl (c), 2,4,6‐triphenylphenyl (d), and 2,4,6‐tri‐tert‐butylphenyl (e)) have been prepared by reactions of ArPH2 (1 a–e) with 1,4‐diferrocenyl butadiyne. Compounds 3 b–e have been structurally characterized by single‐crystal XRD analysis. Application of the sterically demanding 2,4,6‐tri‐tert‐butylphenyl group led to an increased flattening of the pyramidal phosphorus environment. The ferrocenyl units could be oxidized separately, with redox separations of 265 (3 b), 295 (3 c), 340 (3 d), and 315 mV (3 e) in [NnBu4][B(C6F5)4]; these values indicate substantial thermodynamic stability of the mixed‐valence radical cations. Monocationic [3 b]+–[3 e]+ show intervalence charge‐transfer absorptions between 4650 and 5050 cm−1 of moderate intensity and half‐height bandwidth. Compounds 3 c–e with bulky, electron‐rich substituents reveal a significant increase in electronic interactions compared with less demanding groups in 3 a and 3 b. Flattening out: The synthesis of 2,5‐diferrocenyl‐1‐aryl‐1H‐phospholes is presented. Activation parameters of inversion at the phosphorus atom, proof of moderate intervalence charge‐transfer absorptions, as well as planarization and increased aromaticity were all determined (see figure).