CunBO2(OH)(-) (n = 1, 2) clusters were studied by anion photoelectron spectroscopy and density functional calculations. From the experimental photoelectron spectra, the adiabatic detachment energy (ADE) and vertical detachment energy (VDE) of CuBO2(OH)(-) are determined to be 4.00 +/- 0.08 and 4.26 +/- 0.08 eV, and those of Cu2BO2(OH)(-) to be 2.30 +/- 0.08 and 2.58 +/- 0.08 eV. The structures of CunBO2(OH (-) and their corresponding neutrals are assigned by comparison between theoretical calculations and experimental measurements. Both experiment and theory show that CuBO2(OH) can be viewed as a superhalogen, thus, confirmed that OH can behave like a halogen atom to participate in superhalogen formation. (C) 2012 Elsevier B. V. All rights reserved.