Reactions between anionic heptaphosphide clusters ([P-7](3-)/[HP7](2-)) and 2-ethynylpyridine yielded the 4-(2'-pyridyl)-1,2,3-triphospholide anion ([P3C2H(2-C5H4N)](-); 1). This species was isolated as a compositionally pure [K(2,2,2-crypt)](+) salt in moderate yields. Preliminary coordination studies of 1 toward Mo(CO)(6) or Mo(Py)(3)(CO)(3) (py = pyridine) afforded the diamagnetic piano-stool complex [{eta(5)-P3C2H(2-C5H4N)}Mo(CO)(3)](-) (2). By contrast, reaction of 1 with Mo(COD)(CO)(4) (COD = 1,5-cyclooctadiene) yielded [{kappa P-2,N-P3C2H(2-C5H4N)}Mo(CO)(4)](-) (3) which readily loses a carbonyl on heating to give 2. Reaction of 2 with Mo(COD)(CO)(4) afforded the bimetallic system [{mu:eta(5),kappa P-2,N-P3C2H(2-C5H4N)}{Mo(CO)(3)}{Mo(CO)(4)}](-) (4).