The layered-solvothermal synthesis of zinc acetate dihydrate with 5-phosphonobenzene-1,3-dicarboxylic acid yields a three-dimensional rutile-type porous metal-organic framework, which is an anionic open-framework containing local proton transfer with hydrated protons and showing excellent size-selective properties.

Three porous metal-organic frameworks have been constructed from the new developed C3-symmetric hexacarboxylic acid 3,3 0 ,3 00 ,5,5 0 ,5 00 -benzene-1,3,5-triyl-hexabenzoic acid (H 6 BHB) of different NaCl-and Al 2 O 3 -type topologies. The activated metal-organic frameworks (MOFs) exhibit permanent porosities as revealed in their gas and vapor adsorption isotherms, highlighting the promise of this new ligand for the construction of porous MOFs for gas storage and separation.

Two novel metal−organic frameworks (MOFs), Cu(3,4′-bpdc)(H2O)·DMF·2H2O (1) and Cu(3,4′-bpdc)(H2O)·2DMF·4.5H2O (2), have been solvothermally synthesized by the reaction of a unsymmetrically substituted carboxylate ligand 3,4′-biphenyldicarboxylic acid (3,4′-bpdc) and Cu(NO3)2·2.5H2O. X-ray crystal structural analyses reveal that both MOFs possess the binuclear paddle-wheel units [Cu2(O2CR)4], which are linked by the biphenyl connectors, to give two different three-dimensional (3-D) frameworks. The structural diversities are due to the different coordinated arrangements of the two distinct carboxylate groups. In 1, the noncentral symmetrical A−A−B−B arrangement leads to an uncommon twisted Cu-paddlewheel unit, which favors a tetrahedral configuration to generate a 3-fold interpenetrating 3-D framework with a diamond topology. In 2, the paddle-wheel unit constructed by the central symmetrical A−B−A−B arrangement of the ligand acts as a square-planar 4-connected node to give a 2-fold interpenetrating 3-D framework with an NbO topology. These two polymorphs are very rare in MOFs that exhibit similar metal local coordination geometry and the same secondary building units (SBU) but different ligands linking modes. Furthermore, both 1 and 2 possess large one-dimensional channels and show the ability to adsorb H2.

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To systematically explore the assembly mechanism of a rutile-type open framework of {[Zn(3)(pbdc)(2)]·2H(3)O}(n) (3) (H(4)pbdc = 5-phosphonobenzene-1,3-dicarboxylic acid) constructed by 3-connected pbdc ligands and 6-connected Zn(3)(CO(2))(4)(PO(3))(2) secondary building units (Zn(3)-SBUs), three major factors including solvothermal procedures, types of solvents and amines, are taken into consideration. Seven novel structures, namely {[Zn(5)(pbdc)(2)(OH)(2)(H(2)O)(4)]·4H(2)O}(n) (1), {[Zn(3)(pbdc)(2)·H(2)O]·(Htea)·H(3)O·2-5(H(2)O)}(n) (2), {[Zn(3)(pbdc)(2)](H(3)O)(2)(dma)}(n) (4), {[Zn(2)(pbdc)(taea)]·3H(2)O}(n) (5), {[Zn(3)(pbdc)(2)(Hpda)(2)]·2H(2)O}(n) (6), {[Zn(5)(pbdc)(2)(Hpbdc)(2)]·2H(2)pz·9H(2)O}(n) (7), {[Zn(3)(pbdc)(2)]·Hpd·H(3)O·4H(2)O}(n) (8) are obtained. The results indicate that the layered-solvothermal method and the isopropanol solvent play crucial roles in the construction of the special anionic open framework of [Zn(3)(pbdc)(2)](2-). Changing these two factors led molecular assembly away from the rutile-type open framework. However, amines play a variable role in the framework, which means that by using appropriate amines, molecular assembly could generate the open framework of [Zn(3)(pbdc)(2)](2-) with pores decorated by amines. These results suggest a different approach towards decorating pores in anionic frameworks with precise structural information.