Chemistry of the metal carbonyls. Part XLVIII. Complexes of ‘Dewar hexafluorobenzene’

Abstract

Treatment of ‘Dewar hexafluorobenzene’(DHFB, hexafluorobicyclo[2,2,0]hexa-2,5-diene) with the anions [Re(CO)₅]^– or [(π-C₅H₅)Fe(CO)₂]^– leads mainly to a replacement of a vinylic fluorine by the anionic group with retention of the bicyclo[2,2,0]-structure. The reactionof DHFB with enneacarbonyldi-iron is complex; the two compounds (DHFB)Fe(CO)₄ and (DHFB)[Fe(CO)₄]₂ have been characterised. Tetrakis(triphenylphosphine)platinum, acetylacetonatobis(ethylene)rhodium, or chlorocarbonylbis(diphenylmethylphosphine)iridium react with DHFB to give the complexes (Ph₃P)₂Pt(DHFB), (C₂H₄) acac Rh(DHFB), and (Ph₂PCH₃)₂(CO)ClIr(DHFB) in all of which the Dewar structure is retained. Reaction of the platinum derivative with iodine regenerates DHFB. Hydridopentacarbonylrhenium adds rapidly to both double bonds of DHFB to give C₆H₂F₆[Re(CO)₅]₂. The reaction of pentacarbonyltrimethyltinmanganese with DHFB is complex; decafluorodiphenyl and C₆F₆HMn(CO)₅ have been identified as products.