A three-dimensional porous metal-organic framework based on 9,9-dimethylfluorene-2,7-dicarboxylic acid (H2MFDA): {[Tb2(MFDA)3(DMF)2(H2O)3] • (H2O)3(DMF)6} n

The title metal-organic framework, [Tb-2(MFDA)(3)(DMF)(2)(H2O)(3)] center dot (H2O)(3)(DMF)(6)} (n) (I) (H(2)MFDA = 9,9-dimethylfluorene-2,7-dicarboxylic acid, DMF = N,N-dimethylformamide), has been hydrothermally synthesized and structurally characterized by single-crystal X-ray diffraction (CIF file CCDC no. 995892). Complex I crystallizes in triclinic space group with a = 13.0022(3), b = 13.3793(3), c = 25.8929(4) , alpha = 84.060(2)A degrees, beta = 88.104(2)A degrees, gamma = 66.361(2)A degrees, V = 4104.05(15) (3), C75H104N8O26Tb2, M = 1851.50, rho (c) = 1.498 g/cm(3), mu(MoK (alpha)) = 1.790 mm(-1), F(000) = 1896, GOF = 1.055, Z = 2, the final R (1) = 0.0522 and wR (2) = 0.1380 for I > 2 sigma(I). In MOF I, the Tb-2 dinuclear units double-bridged by two carboxylate groups are connected together by MFDA ligands to give rise to a 3D architecture that consists in two types of 1D open channels along the y axis with about 6 x 8 and 9 x 12 (2) dimensions. The solvent accessible space for the desolvated I is 53.4% of the total volume. The 3D structure can also be rationalized as a six-connected (3.4(11).5(2).6) topological network by considering the Tb-2 dinuclear units as six-connected nodes and MFDA ligands as linkers, respectively.