DIPHOSPHOR, PHOSPHOR-, ARSEN- UND ANTIMONATOME ALS CLUSTERBAUGRUPPEN

Article abstract of DOI:10.1016/S0022-328X(00)99683-9

Reactions of Fe2(CO)9 with L_nM-PHal₃ (L_nM = 16-electron fragment: Cp(CO)2Mn, (CO)5Cr, (CO)5Mo, (CO)5W) yield clusters of the type Fe3(CO)9(μ₄-P)2(ML_n)2 (II).Compounds II contain the trigonal bipyramidal cluster framework Fe3(CO)9(μ₃-P)2, the basis of which is a closed triangle formed by three Fe(CO)3 units; the apical positions of the trigonal bipyramid are occupied by phosphorus atoms.Each of the capping phosphorus atoms binds an additional ML_n fragment.Compounds of type II are also obtained from Fe2(CO)6(μ₃-P)2(ML_n)2 (I) by formal addition of an Fe(CO)3 group.A further general synthetic approach to clusters Fe3(CO)9(μ₄-X)2(ML_n)2 (X = P, As, Sb) is the reaction of halo-phosphinidene, arsinidene ar stibinidene complexes, (L_nM)2X-Hal (X= P, As, Sb) with Na2Fe(CO)4.Similar procedures are used for the construction of compounds II and IV.Complexes III contain phosphorus as a μ₄-spiro centre; compounds IV contain metallacyclic phosphanes as ligands.From (CO)5CrPBr3 and Fe2(CO)9 the cluster Fe2(CO)7(P<*>P)2 (V) is obtained in which a diphosphorus unit is side-on and end-on coordinated as an eight-electron ligand.The identity of the new compounds is documented by analytic and spectroscopic data as well as by X-ray-structure analyses of seven compounds.