PERFLUORINATED DIINDACYCLES

The reaction of 1,2-bis(halomercurio)tetrafluorobenzene (halide = chlo ride (3) or bromide (4)) with the corresponding indium(I) halide in TH F results in spontaneous ring closure and formation of the tetrakis(TH F) adducts of hloro-9,10-dihydro-9,10-diindaoctafluoroanthracene (5) a nd bromo-9,10-dihydro-9,10-diindaoctafluoroanthracene (6), respectivel y. Diindacycle 6 can also be prepared by reaction of indium(I) bromide with trimeric perfluoro-o-phenylenemercury in refluxing toluene, foll owed by treatment with THF. Upon addition of pyridine, the ligated THF molecules of 6 are readily displaced and bromo-9,10-dihydro-9,10-diin daoctafluoroanthracene tetrakis(pyridine) (7) is obtained. Compounds 5 -7 have been characterized by H-1, C-13, and F-19 NMR spectroscopy, MS CI, and elemental analysis, and their molecular structure has been det ermined by single-crystal X-ray analysis. All compounds crystallize in monoclinic space groups. Two modifications of compound 6 have been an alyzed. 5: space group P2(1)/c with a = 9.686(1) Angstrom, b = 11.071( 1) Angstrom, c = 15.725(2) Angstrom, beta = 105.55(1)degrees, V = 1624 .5(3) Angstrom(3), and Z = 2. 6: space group P2(1)/c with a = 9.636(1) Angstrom, b = 11.129(1) Angstrom, c = 16.029(2) Angstrom, beta = 104. 40(1)degrees, V = 1664.9(3) Angstrom(3), and Z = 2; space group P2(1)/ c with a = 10.258(1) Angstrom, b = 13.926(1) Angstrom, c = 11.892(2) A ngstrom, beta = 97.86(1)degrees, V = 1682.8(2) Angstrom(3), Z = 2. 7. space group P2(1)/c with a = 17.632(2) Angstrom, b = 15.010(1) Angstro m, c = 14.562(1) Angstrom, beta = 101.72(1)degrees, V = 3773.6(6) Angs trom(3), and Z = 4. The perfluorination of the phenylene rings in 5-7 has a consequent effect on the Lewis acidity of the indium centers whi ch is reflected by the relatively short O-In and N-In dative bond dist ances.