1 Rational Design of Pore Size and Functionality in a Series of Isoreticular Zwitterionic Metal-Organic Frameworks Darpandeep Aulakh,†,|| Timur Islamoglu,‡,|| Veronica F. Bagundes,† Juby R. Varghese,† Kyle Duell,† Monu Joy,† Simon J. Teat,§ Omar K. Farha‡,ǂ and Mario Wriedt*,† †Department of Chemistry & Biomolecular Science, Clarkson University, Potsdam, New York 13699, United States of America ‡Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States of America §Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States of America ǂDepartment of Chemistry, Faculty of Science, King Abdulaziz University, Jeddah 21589, Saudi Arabia ||D.A. and T.I. contributed equally to this work. * Tel.: +1(315) 268-2355 Fax: +1(315) 268-6610 Email:
[email protected] 2 Abstract The isoreticular expansion and functionalization of charged-polarized porosity has been systematically explored by the rational design of eleven isostructural zwitterionic metal-organic frameworks (ZW-MOFs). This extended series of general structural composition {[M3F(L1)3(L2)1.5]·guests}n was prepared by employing the solvothermal reaction of Co and Ni tetrafluoroborates with a binary ligand system composed of zwitterionic pyridinium derivatives and traditional functionalized ditopic carboxylate auxiliary ligands (HL1·Cl = 1-(4- carboxyphenyl)-4,4′-bipyridinium chloride, Hcpb·Cl; or 1-(4-carboxyphenyl-3-hydroxyphenyl)- 4,4′-bipyridinium chloride, Hchpb·Cl; and H2L2 = benzene-1,4-dicarboxylic acid, H2bdc; 2- aminobenzene-1,4-dicarboxylic acid, H2abdc; 2,5-dihydroxy-1,4-benzenedicarboxylic acid, H2dhbdc; biphenyl-4,4’-dicarboxylic acid, H2bpdc; or stilbene-4,4’-dicarboxylic acid, H2sdc). Single-crystal structure analyses revealed cubic crystal symmetry (I-43m, a = 31-36 Å) with a 3D pore system of significant void space (73-81%).