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