Coordination chemistry of organometallic polydentate ligand. Reactive chemistry of the tridentate ligand trans-Fe(Ph(2)PQu-P)(2)(CO)(3)[Ph(2)PQu=2-diphenyl-phosphino-4-methylquinoline] and molecular structure of [Fe(CO)(3)(mu-Ph(2)PQu)(2)HgI](+)[HgI3](-)

Reaction of a new type of bidentate ligand PhPQu [PhPQu = 2-diphenylphosphi no-4-methylquinoline] with Fe(CO)(5) in butanol gave trans-Fe(PhPQu-P)(CO)( 3) (1). Compound 1, which can act as a neutral tridentate organometallic li gand, was reacted with I B, II B metal compounds and a rhodium complex to g ive six binuclear complexes with Fe-M bonds, Fe(CO)(3) (mu-Ph(2)PQu)MXn(2-7 ) [M = Zn(II), Cd(II), Hg(II), Cu(I), Ag(I), Rh(I)], and an ion-pair comple x [Fe(CO)(3)(mu-Ph(2)PQu)(2)HgI][HgI3](-) (8). The structure of 8 was deter mined by X-ray crystallography. Complex 8 crystallizes in the space group P -1 with a = 1.0758(3), b = 1.6210(4), c = 1.7155(4) nm; alpha = 75.60(2), b eta = 71.81(2), gamma = 81.78(2)degrees and Z = 2 and its structure was ref ined to give agreement factors of R = 0.050 and R-w = 0.057. The Fe-Hg bond distance is 0.2536 nn.