SYNTHESIS OF SOME HETEROCYCLIC-DERIVATIVES OF (ETA-ARENE)(ETA-CYCLOPENTADIENYL)IRON(II) HEXAFLUOROPHOSPHATES INCLUDING ESTIMATION OF DIHEDRAL ANGLES IN BOTH FREE AND COMPLEXED LIGANDS

The preparations are described of a series of mono and disubstituted d erivatives of [(eta-arene)(eta-cyclopentadienyl)Fe][PF6] complexes in which a range of indole-related substituents is bonded to the arene mo iety via nitrogen. The preparations involved the SNAr displacement of chlorine from the corresponding chlorobenzene iron sandwich complex by nitrogen-centered anions derived by reaction of the heterocycle with (t)BuOK in DMSO or 80% DMSO-(t)BuOH. The H-1 and C-13 NMR data are pre sented and discussed. Analysis of the C-C-13 data using substituent ch emical shifts of the ortho and meta carbons of the arene moiety has al lowed estimation of the dihedral angle between the arene and the heter ocyclic components in both the free and complexed N-phenyl heterocycli c systems.