The reaction of 1,3,5-cis-triazidocyclohexane with the electron-rich tris(dialkylamino)phosphines P(NMe2)(3) (1) and N(CH2CH2NMe)(3)P (2b) in acetonitrile for 3 h furnished the corresponding tris-phosphazides 1,3,5-cis-(R3PN3)(3)C6H9, 3a (R3P = 1) and 3b (R3P = 2b), in 90% and 92% yields, respectively. The same reaction with the relatively electron-poor tris(dialkylamino)phosphine MeC(CH2NMe)(3)P (4) for 2 days gave the tris-iminophosphorane, 1,3,5cis-(R3PN)(3)C6H9, 5a (R3P = 4), in 60% yield. Compound 3b is a thermally stable solid that did not lose dinitrogen when refluxed in toluene for 24 h or when heated as a neat sample at 100 degreesC/0.5 Torr for 10 h. By contrast, tris-phosphazide 3a decomposed to the tris-iminophosphorane 1,3,5-cis-(R3PN)(3)C6H9, 5b (R3P = 1), in 3 h in quantitative yield upon heating to 100 degreesC in toluene. Factors influencing the formation of the phosphazides or the iminophosphoranes in these reactions are discussed. The reaction of 3b with 4 equiv of benzoic acid gave [N(CH2CH2NMe)(3)P=NH2]PhCO2 {[6bH]]PhCO2] in quantitative yield along with benzene (56% yield) and dinitrogen, The same reaction with 3a gave [(Me2N)(3)P=NH2]PhCO2 {[7aH]PhCO2} (quantitative yield), benzene (15% yield), and dinitrogen. Treatment of [6bH]PhCO2 with KOtBu afforded N(CH2CH2NMe)(3)P=NH (6b) in 40% overall yield. Compound 6b upon treatment with PhCH2CH2Br produced [6bH]Br in 90% yield along with styrene. The new compounds were characterized by analytical and spectroscopic methods, and selected compounds (3b, 5a, and [6bH]Br) were structured by X-ray crystallography. A special feature of 3b is its capability to function as a starting material for 6b, which was not accessible by other synthetic routes.