CRYSTAL AND MOLECULAR-STRUCTURES OF PENTAPHENYLCYCLOPENTADIENE AND OF AN ISOMER, 4,8-DIPHENYLTRIBENZO[B,F,I]TRICYCLO[6.2.1.01,5]UNDECANE, THE PRODUCT OF A NOVEL METAL-ASSISTED PHOTOREACTION

The crystal and molecular structures of two isomers of C35H26, pentaphenylcyclopentadiene, C5(C6H5)5H (I), and 4,8-diphenyltribenzo[b,f,i]tricyclo[6.2.1.0(1,5)]undecane(II)are described. Pentaphenylcyclopentadiene crystallizes from tetrahydrofuran in the monoclinic space group P2(1)/c with a = 15.954 (4) angstrom, b = 6.267 (1) angstrom, c = 24.517 (8) angstrom, beta = 93.94 (2)-degrees, V = 2445 (1) angstrom3, Z = 4, D(calcd) = 1.213 g cm-3 , R = 0.038, and R(w) = 0.045. 4,8-Diphenyltribenzo[b,f,i]tricyclo[6.2.1.0(1,5)]undecane crystallizes from methanol/ether/hexane (1:1:2) in the monoclinic space group P2(1)/n with a = 10.710 (2) angstrom, b = 10.754 (3) angstrom, c = 20.683 (4) angstrom, beta = 97.30 (2)-degrees, V = 2363 (9) angstrom3, Z = 4, D(calcd) = 1.256 g cm-3, R = 0.034, and R(w) = 0.043. Compound II was obtained by the photochemical isomerization of the pentaphenylcyclopentadienyl ligand attached to the iron center in [Fe(eta-5-C5Ph5)(eta-6-C6H6)+BPh4- in the presence of triethyl phosphite.