The alkoxy- and aryloxy-functionalized bis(phosphanyl)hydrazines of the type (OR)(2)PN(Me)N(Me)P(OR)(2) were obtained from the reactions of the corresponding alcohols and phenols with Cl2PN(Me)N(Me)PCl2 in the presence of Et(3)N. interaction of these ligands with group 6 metal carbonyl precursors M(CO)(4)(NHC5H10)(2) (M = Mo, W) gave the tetracarbonyl complexes of the type cis-[M(CO)(4)(OR)(2)PN(Me)N(Me)P(OR)(2)}]. The reactions of the alkoxy and aryloxy-functionalized bis(phosphanyl)hydrazines with Pd(PhCN)(2)Cl-2 or with Pt(COD)Cl-2 resulted in the formation of the complexes of the type cis-[MCl(2)(OR)(2)PN(Me)N(Me)P(OR)(2)}]. The ligands are bound cis to the metal center(s) in all the complexes. The structures of all the complexes have been established by combination of spectroscopic and elemental analysis. As representative examples, we have determined the structures of cis-[W(CO)(4){(OPh)(2)PN(Me)N(Me)P(OPh)(2)}] (15) and cis-[PdCl2{(OC6H4Br-p)(2)PN(Me)N(Me)P(OC6H4Br-P)(2)}] (19) by X-ray crystallography. X-ray data for 15 : monoclinic, P2(1)/n, a = 13.419(5) Angstrom, b = 19.588(3) Angstrom, c = 12.253(3) Angstrom, beta = 103.65(2)degrees, Z = 4, and R = 0.025 (R(w) = 0.033). X-ray data for 19 : triclinic, P ($) over bar 1, a = 9.252(3) Angstrom, b = 9.882(3) Angstrom, c = 17.739(5) Angstrom, alpha = 83.84(2)degrees, beta = 83.98(2)degrees, gamma = 84.45(2)degrees, Z = 2, and R = 0.064 (R(w) = 0.076).