Synthesis of novel copper compounds containing isonicotinic acid and/or 2,6-pyridinedicarboxylic acid: third-order nonlinear optical properties

Two novel compounds, [Cu₂(pydc)₂(inta)₂(H₂O)₂]·3H₂O 1 (pydc?=?2,6-pyridinedicarboxylic acid, inta?= isonicotinic acid) and [Cu(pydc)₂][Cu(H₂O)₅]·2H₂O 2, have been synthesized in aqueous solution and characterized by single-crystal X-ray diffraction, elemental analyses and IR spectra. Compound 1 exhibits reverse saturable absorption and self-defocusing. X-ray structural analysis reveals that Compounds 1 and 2 both possess π–π stacking and hydrogen-bonding interactions forming three-dimensional (3D) networks. Crystal data for 1: a?=?7.2345(14), b?=?12.219(2), c?=?17.069(3)?Å, α?=?90.44(3), β?=?91.82(3), γ?=?93.56(3)°, Z?=?1, R1?=?0.0435, wR2?=?0.1216. Crystal data for 2: a?=?8.3708(17), b?=?27.386(6), c?=?9.6170(19)?Å, α?=?90.00, β?=?98.14(3), γ?=?90.00°, Z?=?3, R1?=?0.0742, wR2?=?0.2160.