The title tetranuclear complex, (mu(4)-oxo)-hexakis(mu(2)-chloro)-tetrakis(2-amino-1,3-thiazole-N)-tetra-copper(11) [Cu-4(mu(4)-O)(mu-Cl)(6)L-4] (1, L = 2-amino-1,3-thiazole) was synthesized by the reaction of CuCl2 2H(2)O with 2-amino-1,3-thiazole in methanol and characterized by IR spectra and X-ray diffraction Complex 1 crystallizes in triclinic, space group P (1) over bar with a = 9 7137(2), b = 10 7005(2), c = 14 6505(2) angstrom, alpha = 83 9550(10), beta = 82 0930(10), gamma = 67 1640(10)degrees, V = 1387 84(4) angstrom(3), M-r = 883 43, Z = 2, mu = 3 927 mm (1), D-c = 2 1144 g/cm(3), F(000) = 868, R = 0 0332 and wR = 0814 The complex contains a tetrahedron of four Cull atoms coordinating to a central mu(4)-O atom, with the six edges of the tetrahedron bridged by six Cl atoms The Cu-O bond distances range from 1 910(2) to 1 918(2) angstrom, Cu-Cl from 2 3501(11) to 2 5924(10) angstrom, and Cu-Cu from 3 1003(6) to 3 1663(6) angstrom The coordination geometries of the four coppers distort from trigonal bipramid to tetragonal pyramid with different distortion factors The free ammo groups of the ligands result in a lot of N-H Cl and N-H N intra- and intermolecular hydrogen bonds