Bis(3-dimethylaminopropyl)diselenide was prepared by the reaction of Na2Se2 with Me2NCH2CH2CH2Cl. 3-Dimethylaminopropylselenolate complexes of palladium and platinum of the formulae [M(SeCH2CH2CH2NMe2)Cl](2), [M(SeCH2CH2 CH2NMe2)(2)] (M = Pd or Pt), [Pd(OAc)(SeCH2CH2CH2NMe2)], [PtCl(SeCH2CH2CH2NMe2)(PR3)](2) (PR3 = PMePh2 or PPr3), [Pt(SeCH2CH2CH2NMe2)(2)(P-P)] (P-P = dppm, dppe or 2PPh(3)) have been synthesized by using either the diselenide or its reduction product from the reaction with NaBH4. All complexes have been characterized by elemental analysis, IR and NMR (H-1, C-13, P-31, Se-77, Pt-195) spectroscopy. The stereochemistry of these complexes has been deduced from the NMR spectroscopic data. The structure of [Pd(SeCH2CH2CH2NMe2)Cl](2) was established by single crystal X-ray diffraction analysis. Each palladium atom in the dimer is surrounded by two mu-Se atoms, a nitrogen atom and a chloride ligand. (C) 2003 Elsevier Science B.V. All rights reserved.