Synthesis, structural characterization and third-order non-linear optical property of new three-dimensional metal-organic framework K•Na•[M2II(μ6-btc)(μ2-ox)(H2O)2]•2H2O (M = Ni, Co)

Two three-dimensional (3-D) isostructural metal-organic frameworks K (.) Na (.) [M-2(11)(mu(6)-btc)(mu(2)-ox)(H2O)(2)](.)2H(2)O (M = Ni, Co; btc = 1,2,4,5-benzenetetracarboxylate, pyramellitate, C10H2O84-; ox = oxalate C2O42-) have been synthesized hydrothermally and characterized by single-crystal X-ray diffraction. Each 3-D structure is built from the linkage of secondary building units of trinuclear [M-3(CO2)(3)] clusters by a mixed connector of oxalate and pyromellitate. The third-order non-linear optical properties of the title compounds, were studied and both exhibit the reverse saturable absorption and self-defocusing performance with the gamma values of 5.03 x 10(-30) esu for 1 and 3.04 x 10(-30) esu for 2. (c) 2005 Elsevier B.V. All rights reserved.