Interpniktogenkationen: Neue Perspektiven in der Koordinationschemie

Abstract

Pniktanderivate können die Rolle von sowohl 2 e−‐Donoren (Lewis‐Basen) als auch 2 e−‐Akzeptoren (Lewis‐Säuren) übernehmen. Als prototypische Liganden in der Koordinationschemie von Übergangsmetallen bilden Amine und Phosphane auch Komplexe mit Lewis‐Säuren des p‐Blocks, die verschiedene Pniktogen‐zentrierte Akzeptoren umfassen. Die Lewis‐Acidität von Pniktogenzentren kann durch eine kationische Ladung verstärkt werden, was in den letzten Jahren zur Entwicklung von Verbindungen mit koordinativen Pn‐Pn‐ und Pn‐Pn′‐Wechselwirkungen genutzt wurde. Diese Verbindungen bieten die außergewöhnliche Möglichkeit zur homoatomaren Koordinationsbindung und ermöglichen die Entwicklung von Komplexen mit einem freien Elektronenpaar am Akzeptorzentrum. Dieser Aufsatz weist neue Richtungen für die systematische Erweiterung der Koordinationschemie von der Übergangsreihe zum p‐Block.

Coordination Complexes of Ph3Sb2+ and Ph3Bi2+: Beyond Pnictonium Cations

“…In conclusion, the first structurally characterized examples of ligand-stabilized Ph 3 Sb 2+ and Ph 3 Bi 2+ acceptors have been prepared by displacement of triflate anions in Ph 3 Pn-(OTf) 2 [Pn = Sb (1 a) or Bi (1 b)] by the neutral donors, OPPh 3 , dmap and bipy. The new complexes exhibit structural diversity dictated by the steric demands and the nature of the ligands.…”

“…The syntheses of all six compounds were carried out by analogous method, presented as a representative example for [31] [Ph 3 Sb(dmap) 2 …”

“…Cationic frameworks exhibit an enhanced Lewis acidity compared with neutral analogues and recent reports of cationic complexes of p-block acceptors represent a new direction for coordination chemistry. [2,3] For example, complexes of mono-, [4] di-, [5] and tricationic [6] + , through sequential replacement of an anionic substituent (X) by neutral ligand(s) (L). Indeed, a number of cationic complexes containing tetrahedral P V acceptor centers have been structurally characterized, [7][8][9][10][11] although in all but a single case [7] ligand coordination is facilitated by a low coordination number at a phosphorus center involved in multiple bonding.…”

“…Abstract: The syntheses of salts containing ligand-stabilized Ph 3 Sb 2+ and Ph 3 Bi 2+ dications have been realized by in situ formation of Ph 3 Pn(OTf) 2 (Pn = Sb or Bi) and subsequent reaction with OPPh 3 , dmap and bipy. The solid-state structures demonstrate diversity imposed by the steric demands and nature of the ligands.…”

Functionalization of Pentaphosphorus Cations by Complexation

“…[10] In addition, Cummins and co-workers have very impressively demonstrated the synthetic potential of polyphosphido transition metalate anions for the synthesis of useful and novel Pcompounds. [12] Recent studies clearly show the substantial influence of cationic substituents,f or example,N HCs [13] and phosphanes, [14] on their stability and reactivity. [12] Recent studies clearly show the substantial influence of cationic substituents,f or example,N HCs [13] and phosphanes, [14] on their stability and reactivity.…”