The compounds Cp2Y[eta(3)-N(QPPh(2))(2)] (Q = S (1), Se (2)) have been synthesized in good yield from the protonolysis reaction between Cp3Y and HN(QPPh(2))(2) in tetrahydrofuran. In both compounds, the [N(QPPh(2))(2)](-) ligand is bound eta(3) to the Y center which, in 1, represents the first example of that mode of binding for the sulfur-containing ligand. The Y atom is also coordinated to two (C5H5)(-) ligands and so is formally 9-coordinate. Both 1 and 2 are stable in inert environments for prolonged periods of time. Each is soluble in THF and CH2Cl2. H-1, P-31,: Se-77, and Y-89 NMR data were collected to lend insight into the solution properties of these molecules. Crystallographic data for 1 (-120 degrees C): C34H30NP2S2Y, triclinic, P (1) over bar, a = 9.685(5) Angstrom, b = 12.176(6) Angstrom, c = 13.978(7) Angstrom, alpha = 87.382(9)degrees, beta = 87.358(9)degrees, gamma = 68.689(9)degrees, V = 1533(1) Angstrom(3), Z = 2, and R-1(F) = 0.047 for the 4023 reflections with I > 2 sigma(I). Crystallographic data for 2 (-120 degrees C): C34H30NP2Se2Y, triclinic, P (1) over bar, a = 9.745(5) Angstrom, b = 12.222(6) Angstrom, c = 13.930(7) Angstrom, alpha = 88.024(9)degrees, beta = 87.380(9)degrees, gamma = 69.137(9)degrees, V = 1548(1) Angstrom(3), Z = 2, and R-1(F) = 0.056 for the 4324 reflections with I > 2 sigma(I).