SITE-DIRECTED ALKYLATION OF [EFE3(CO)(9)](2-) (E = S, SE, TE) MEDIATED BY THE CHALCOGENIDE - SYNTHESIS, SPECTROSCOPIC CHARACTERIZATION, ANDREACTIVITY OF [PPN][MEFE3(CO)(9)E] (E = SE, TE)

The compounds [PPN](2)[EFe3(CO)(9)] (E= S ([PPN](2)[Ib], E = Se ([PPN] (2)[Ic]), and E=Te ([PPN](2)[Id])) (PPN = [(Ph3P)(2)N](+)) were alkyla ted using methyl triflate or methyl iodide. [PPN](2)[Ib] reacted with methyl triflate at the sulfur atom to form [PPN][Fe-3(CO)(9)SMe] ([PPN ][IVb]). In contrast, alkylation of [PPN](2)[Ic] and [PPN](2)[Id] occu rred at the metal framework giving [PPN][MeFe3(CO)SE] (E = Se, [PPN][V c], Te = [PPN][Vd]), of which [PPN][Vc] was characterized by X-ray cry stallography. Compounds [PPN][Vc] and [PPN][Vd] represent new examples of the uncommon class of cluster compounds having alkyl groups termin ally bound to a metal carbonyl cluster compound. The crystal structure of[PPN][Vc] shows a long Fe-Me distance of 2.226(9) Angstrom. The rem oval of electron density from the parent clusters [IC](2-) and [Id](2- ) could be seen in the trends of the Se-77 or Te-125 chemical shifts f or [Vc](-), [Vd](-), and some structurally related compounds.