The anionic polymerization of butadiene initiated with 1,4-dilithio-1,1,4,4-tetraphenylbutane (LiTPB) in diethyl ether (DEE) gives polybutadiene (PBD) with high 1,2 content (>70%), narrow polydispersities (1.04 < M-w/M-n < 1.20), and predicted molecular weights. In THF, this polymerization does not work very well. After removal of DEE and addition of THF, the PBD dianion is end capped quantitatively by addition of 1,1-diphenylethylene (DPE) to give the diphenylalkyl end capped PBD dianion. Subsequent addition of methyl methacrylate at low temperatures results in the formation of well-defined PMMA-b-PBD-b-PMMA triblock copolymers. The results are accounted for by taking into account the effects of Li ion solvation on the BD initiation and end capping of the PBD anion by DPE. (C) 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 2198-2206, 2009