Iron- and Ruthenium-Linked Phosphazenes

Article abstract of DOI:10.1021/ja00343a041

A series of new organometallic phosphazenes that contains Fe-P, Ru-P, Ru-Ru, and Fe-Ru bonds has been isolated.The anions ^- and ^- react with (NPF2)3 (2) to replace first one and then two (geminal) fluorine atoms by M(CO)2Cp groups.The monoruthenium derivative (5) reacts with ^- to form a geminal, mixed-metal organometallic phosphazene (7) that, on photolysis, undergoes decarbonylation to an Fe-Ru bonded derivative (8).The monoiron cyclotriphosphazene (9) does not yield the same mixed-metal species when treated with ^- but instead forms the new mixed-metal dimer, FeRu(CO)4Cp2 (10).This dimer can also be prepared by the reaction of ^- with Fe(CO)2CpI.Species 8 and its diiron analogue, 4, undergo metal-metal bond cleavage with carbon monoxide.Species 7 and 8 are the first examples of phosphazenes with two different metals linked to a phosphazene ring.The new compounds were characterized by 31P, 19F, and 1H NMR, infrared, and mass spectral techniques.In addition, an X-ray crystal structure analysis of the mixed-metal phosphazene 8 was carried out.The Fe-Ru bond distance in 8 is 2.698 (1) Angstroem and the Fe-P-Ru bond angle is 73.93 (2) deg.Evidence was obtained that the organometallic unit perturbs the structure of the phosphazene ring.