The potential of an extremely hydrophobic cobalt(II) catalyst for the synthesis of polymer nanolatexes in microemulsion polymerization is investigated. Colloidally stable nanolatexes have been successfully synthesized in microemulsion polymerization of styrene, butyl methacrylate, and 2-ethylhexyl methacrylate and in the presence of bis[(difluoronoryl)-diphenylglyoximato]cobalt(II). The average particle diameter can be reduced from 50 nm to approximately 10 nm in the presence of minor quantities of the cobalt(II) complex. The small particle size, combined with the relatively narrow particle size distribution, results in nanolatexes that are virtually transparent in appearance. Furthermore, the nucleation efficiency can be enhanced by up to two orders of magnitude, corresponding to approximately 1 particle nucleated for every 10(1) micelles. This represents a significant improvement as in microemulsion polymerization generally 1 particle is nucleated for every 10(3) micelles. (c) 2012 Elsevier Inc. All rights reserved.