Structure, luminescence, and adsorption properties of two chiral microporous metal-organic frameworks

Two 3D chiral multifunctional microporous MOFs, Zn3(BTC)2(DMF)3(H2O).(DMF)(H2O) (1) and Cd(4)(BTC)3(DMF)2(H2O)2.6(H2O) (2) (H(3)BTC = 1,3,5-benzenetricarboxylic acid and DMF = N,N'-dimethylformamide), have been synthesized in the presence of organic bases tributylamine (TBA) and triethylamine (TEA), respectively. 1 (C(30)H(38)N(4)O(18)Zn(3)) crystallizes in the tetragonal P4(1)2(1)2 space group (a = 13.6929(19) A, c = 50.664(10) A, V = 9499(3) A(3), and Z = 8). 2 (C33H39N2O28Cd4) crystallizes in the tetragonal P4(3)22 space group (a = 10.3503(4) A, c = 52.557(3) A, V = 5630.4(4) A(3), and Z = 4). X-ray crystallography reveals that 1 consists of a 3D open framework with the (6(3))(4)(6(2).8(2).10(2))(6.(4)8(2))(2) topology, but 2 exhibits a 3D open network with the (4(2).5)(2)(4.(4)5.(10)6.(8)7.(4)8(2)) topology. The solid-state excitation-emission spectra show that the strongest excitation peaks for 1 and 2 are at 341 and 319 nm, and their emission spectra mainly show strong peaks at 410 and 405 nm, respectively. The amounts adsorbed of 1 (2) are 169 mg/g (126 mg/g) for H2O, 137 mg/g (102 mg/g) for C2H5OH, and 133 mg/g (99 mg/g) for CH3OH, which are equivalent to the adsorption of about 62 (34) H2O, 20 (11) C2H5OH, and 28 (16) CH3OH per unit cell, respectively.