Structural and zeolitic features of a series of heterometallic supramolecular porous architectures based on tetrahedral {M(C2O4)4}4- primary building units.
The utilization of tetrahedral pre-formed coordination compounds {M(C2O4)4}4- (M = Zr(IV), U(IV); C2O4(2-) = oxalate) permitted the efficient construction of rare examples of heteronuclear supramolecular nano-porous architectures. A series of metal-organic coordination frameworks prepared by association of these building units with either Mn2+, Cd2+, or Mg2+ have been structurally characterized and are described. Their 3-D chemical scaffold is based on the primary tetrahedral building unit but their pore sizes and topologies could be varied through the M2+ metal ion involved in the assembling process, and the anionic tetrahedral moiety. These structures display channels with apertures up to 12 Angstrom x 8 Angstrom which are emptied of solvates at mild temperatures without affecting the chemical scaffold, the integrity of which is maintained up to 250-300 degrees C. A certain degree of flexibility of the coordination polymers upon guest release is suggested by the temperature dependence of the powder X-ray patterns and N2 sorption experiments, but reversible and selective sorption of small molecules has been observed substantiating that these open-frameworks behave like sponges.
Imaz
Inhar
I
Institut de Chimie de la Matière Condensée de Bordeaux-CNRS, Université Bordeaux 1, 87 Avenue du Dr. Schweitzer, F-33608, Pessac, France.
Bravic
Georges
G
Sutter
Jean-Pascal
JP
D002104:Cadmium / Q000737:chemistry; D018360:Crystallography, X-Ray; D046911:Macromolecular Substances / Q000138:chemical synthesis / Q000737:chemistry; D008274:Magnesium / Q000737:chemistry; D008345:Manganese / Q000737:chemistry; D008958:Models, Molecular; D009942:Organometallic Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D010070:Oxalates / Q000737:chemistry*; D016062:Porosity; D014501:Uranium / Q000737:chemistry*; D017641:Zeolites / Q000737:chemistry*; D015040:Zirconium / Q000737:chemistry*
D046911:Macromolecular Substances; D009942:Organometallic Compounds; D010070:Oxalates; D002104:Cadmium; D017641:Zeolites; D008345:Manganese; D014501:Uranium; D015040:Zirconium; D008274:Magnesium