Dinuclear metallohydrolases are ubiquitously involved in biological transformations. For understanding and application purpose, significant efforts have been dedicated to the structural or/and functional mimics. Herein, a dinuclear Co(II) complex, CO2L, with intramolecular (beta-CDs is presented. The (beta-CDs confine a hydrophobic microenvironment that contributes to the valence stability of the ligated Co(II) ions. Species of CO2L in aqueous solution is clarified according to the results of potentiometric titration and UV-vis titration experiments. A highly positive-charged species [Co2HL](4+) is present at quasi-neutral condition, which contributed significantly to the binding and activity toward bis(4-nitrophenyl) phosphate (BNPP) assisted by the hydrophobic interactions exerted by intramolecular beta-CDs. The k(cat)/K-M value of CO2L is determined to be 9.8 x 10(-2) M-1 s(-1) at pH 6.5 and 308 K, which exceeds that of the reported zinc analog (Zn2L) by three orders of magnitude. Unexpectedly, CO2L also catalyzes hydrolysis of a phosphate monoester, 4-nitrophenyl phosphate (NPP). The observed phosphate esterase activities are rarely reported among synthetic Co(II) complexes. (C) 2014 Elsevier B.V. All rights reserved.