A silsesquioxane cage polymer functionalized with eight chloropropyl arms (1, T8-PrCl) reacted with 2,2′-dipyridiylamine (DPA) to afford a new derivative with eight pendant linear chains (2, T8-Pr-DPA). Further reaction with [Mo(η3-C3H5)Br(CO)2(NCMe)2] afforded another derivative containing three molybdenum units (3, T8-Pr-DPA-Mo), after substitution of the two nitrile ligands in each complex. These are the first silsesquioxane species containing DPA and the Mo(η3-C3H5)Br(CO)2 fragment. The three materials were characterized by 1H, 13C, 29Si, and 95Mo NMR, FTIR, XRD, and elemental analysis, and T8-PrCl (1) was also structurally characterized by single-crystal X-ray diffraction. It was identified as a low-temperature polymorph of this material. Elemental analysis indicated that all Cl atoms in the parent material T8-PrCl (1) were substituted by the deprotonated DPA group in T8-Pr-DPA (2). However, only three [Mo(η3-C3H5)Br(CO)2(DPA)] units were detected in T8-Pr-DPA-Mo (3). A comprehensive NMR study, compl...