Synthese und Charakterisierung stabiler Bis(phosphonio)isophosphindolylium‐Carbonylmetallate und eines kationischen Bis(phosphonio)isophosphindolylium‐Gold‐Komplexes

Abstract

Synthesis and Characterisation of Stable Bis(phosphonio)isophosphindolyliumcarbonylmetallates and a Cationic Bis(phosphonio)isophosphindolylium‐Gold Complex Herrn Professor Alfred Schmidpeter zum 65. Geburtstag gewidmet. Reaction of 1,3‐bis(triphenylphosphonio)isophosphindolylium bromide, [L + ][Br − ] ( 1a ), with Tl[Co(CO) 4 ], Na[MoCp‐(CO) 3 ], or Na[WCp(CO) 3 ] ( 5a‐c ) yields the corresponding ionic isophosphindolylium‐carbonylmetallates, 6a‐c. Whereas 1a fails to react with neutral metal carbonyls, a mixture of ionic complexes of the type [LAuX + ][AuYZ − ] ( 7a , X, Y, Z = Cl or Br) is formed by reaction with two equivalents of AuCl. Treatment of AuCl with the triflate [L + ][OTf − ] ( 1b ), which is accessible from 1a via anion metathesis, furnishes [LAuCl + ][OTf − ] ( 7b ). Both the carbonylmetallate 6c and the complex 7b have been characterized by X‐ray structure analyses. 7b displays enhanced reactivity as compared to 1b towards MeOH and H 2 O, forming the addition products 8 and 9a, b , the latter existing as two different diastereomers. Reactions of 7b with LiF, (Me 2 N) 3 PO, and (Et 2 N) 2 CNH), respectively, proceed via ligand exchange to yield equilibrium mixtures containing the cations [L + ] and [LAuCl + ].