Eine Familie mit komplexiertem Triphosphaallyl‐Radikal, ‐Kation und ‐Anion

Abstract

Radikal für Redoxstudien: Die Photolyse von [Cp*P{W(CO)5}2] mit einem Diphosphen verläuft über ein radikalisches Intermediat und liefert ein luftstabiles komplexiertes Triphosphaallylradikal, in dem das ungepaarte Elektron gleichmäßig über beide terminale P‐Atome verteilt ist. Die Oxidation des Radikals führt zu dem lediglich bei tiefen Temperaturen in Lösung stabilen Triphosphaallylkation, während bei der Reduktion das stabile Triphosphaallylanion gebildet wird. Mes*=2,4,6‐Tri‐tert‐butylphenyl.

Synthesis and EPR/UV/Vis‐NIR Spectroelectrochemical Investigation of a Persistent Phosphanyl Radical Dication

“…[12] Forc ompound 12[OTf] 2 aq uartet resonance is observed at d = À54.4 ppm with a 2 J PH coupling constant of 9Hzc onsistent with am ethyl group attached to the three-coordinate Patom. TheP ÀCbond lengths (P1À C1 1.813(3) , P1 À C29 1.821 (2) ) are in the expected range and comparable to those observed for dication 9 2+ (P1 À C1 1.838(3) , P1 À C29 1.820(2) ). TheP ÀCbond lengths (P1À C1 1.813(3) , P1 À C29 1.821 (2) ) are in the expected range and comparable to those observed for dication 9 2+ (P1 À C1 1.838(3) , P1 À C29 1.820(2) ).…”

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The reaction of the bis(imidazoliumyl)-substituted P I cation [(2-Im Dipp )P(4-Im Dipp )] + (10 + )(2-Im = imidazolium-2-yl;4 -Im = imidazolium-4-yl;D ipp = 2,6-di-isopropylphenyl) with trifluoromethanesulfonic acid (HOTf) or methyl trifluoromethylsulfonate (MeOTf) yields the corresponding protonated [(2-Im Dipp )PH(4-Im Dipp )] 2+ (11 2+ )a nd methylated [(2-Im Dipp )PMe(4-Im Dipp )] 2+ (12 2+ )d ications, respectively.E PR/UV/Vis-NIR spectroelectrochemical investigation of the low-coordinated P I cation 10 + predicted astable and "bottleable" P-centered radical dication [(2-Im Dipp )P(4-Im Dipp )] 2+ C (13 2+ C). [2] However, only af ew examples are known that are stable enough to be isolated in the solid state.Representative examples of isolated and structurally characterized neutral (1C-5C), [3][4][5][6] anionic (6 À C), [7] and cationic (7 + C, 8 + C) [8,9] derivatives are depicted in Scheme 1. Quantum chemical investigation revealed an exceptional high spin density at the Patom.

Among several bonding motifs possible for charged and uncharged P 1 -centered radicals,p hosphanyl radicals are particularly intriguing.

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Stepwise Expansion of a Cp* Ring at Pentelidene Complexes and Stereoselective Formation of Triphosphines

“…Moreover, under photolytic conditions, a radical Cp* displacement is found. [30] Received: August 28, 2009 Published online: December 2, 2009 . Keywords: arsenic · pentamethylcyclopentadiene · pentelidene complexes · phosphorus · triphosphines…”

Anorganische Chemie 2009

“…In komplexierter Form sind sie sogar luftstabil. So gebildetes (5) kann oxidiert oder reduziert werden, so dass bei gleichen Substituenten die gesamte Phosphaallyl‐Serie vom Anion über das Radikal zum Kation verwirklicht und mehrheitlich sogar strukturell untersucht werden konnte 1_11…”