Abstract : Hexachlorocyclotriphosphazene, (NPCi2)3, reacts with disodium octacarbonyldikferrate, Na2Fe2(CO)8, to yield the diiron and triiron cyclotriphosphazene complexes. The analogous cyclic tetramer (NPCl2)4 reacts similarly to yield the diiron and triiron analogues 5 and 6, respectively. Compounds 2 and 5 are the first chlorophosphazenes that contain two metal-phosphorus covalent bonds and a three-membered spirocyclic ring at phosphorus. Compound 3 can also be obtained by the thermal reaction of 2 with the neutral carbonyl complexes Fe(CO)5 and Fe2(CO)9. In addition, the thermal reaction of 2 with Ru3(CO)12 yields the mixed-metal cluster 7, similar in structure to 3, but with a Ru(CO)3 unit in place of the nitrogen-bound Fe(CO)3. The trimetallic clusters 3, 6, and 7 are the first phosphazene compounds in which a portion of the phosphazene ring has been incorporated into a metallic cluster unit. Compounds 3, 6, and 7 contain both phosphorus-metal and nitrogen-metal bonds, demonstrating both the covalent and coordinative capacities of phosphazene rings. The new metallophosphazenes were characterized by 31P NMR, Mossbauer, infrared, and mass spectral techniques by X-ray crystal structure analyses. Originator supplied keywords include: Cyclophosphazenes, Metallic clusters, Metallophosphazenes, and Mossbauer spectroscopy.