Water-soluble palladium complexes cis-[Pd(L)(OAc)(2)] (1-8) (L represents a diphosphine ligands of the general formula CH2(CH2PR2)(2), where for a: R = (CH2)(6)OH; b-g: R = (CH2)(n)P(O)(OEt)(2), n = 2-6 and n = 8; h: R = (CH2)(3)NH2) have been employed, after activation with a large excess of HBF4, for emulsion polymerization of alkenes (propene, butene, and their equimolar mixtures) with carbon monoxide. Aliphatic polyketone lattices with a high solid content (21%), high molecular weight (6.3 x 10(4) g mol(-1)), and narrow polydispersities (M-w/M-n approximate to 2) were isolated. The catalytic activity of the dicationic palladium (II) based catalysts, C1-C8 is highly dependent on the length of the alkyl chain of the ligand. Catalyst 3 proved to be highly active for propene/CO copolymers, whereas 6 is active for butene/CO and propene/CO-butene/CO systems. The presence of methyl beta-cyclodextrin, as a phase-transfer agent, and undecenoic acid, as an emulsifier, increase the molar mass and the stability of the polyketones and finally the activity of the catalyst. (C) 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 6715-6725, 2009