A novel hexaaza macrocycle bearing two hydroxyethyl pendants (L), 3,6,9,16,19,22-hexaaza-6,19-bis(2-hydroxyethyl)-tricyclo[22,2,2,2(11,14)]triaconta-1,11,13,24,27,29-hexaene, was synthesized as a potential binucleating ligand. The corresponding Cu(II) complex [Cu2LCl2]Cl-2.5.5H(2)O was isolated as a blue crystal, triclinic, space group P (1) over bar, with a = 9.4920(19) Angstrom, b = 4.783(3) Angstrom, c 16.553(3) Angstrom, a = 63.87(3)degrees, alpha = 86.10(3)degrees, gamma = 83.8(3)degrees, V = 2072.8(7) Angstrom(-3), Z = 2, R1 = 0.0658, and wR2 0.1839. Both Cu ions adopt the geometry of a distorted trigonal bipyramid in a pentacoordinated environment. A complexation study on the novel title complex has revealed that the alcoholic OH groups of the complex Cu2L exhibit an obvious acidity with rather low pK(a) values at 25 degreesC. The Cu(II)-bound alkoxides, which act as reactive nucleophiles toward the hydrolysis of 4-nitrophenyl acetate in 10% (v/v) CH3CN at 25 degreesC, with l = 0.10 (NaNO3) and pH 9.3, have shown a second-order rate constant, 0.41 +/- 0.02 M-1 s(-1), a value that is approximately 10 times greater than the corresponding value for the mononuclear Cu(II) complex formed by a relatively simple tripodal ligand (L1). The pH-rate profile gave a sigmoidal curve, The possible catalytic mechanism has been proposed, and the reason for the high catalytic activity of the title complex has been discussed.