Synthesis, crystal structure and thermal properties of Ca6(C12H14O4)4(CO3)(OH)2(H2O)x--a 3D inorganic hybrid material.
The inorganic-organic compound Ca(6)(1,3-adamantanedicarboxylate)(4)(CO(3))(OH)(2)(H(2)O)(x) with 0 < x < 15.2 was synthesized by hydrothermal methods. The crystal structure was determined on the basis of high resolution synchrotron powder diffraction data and poly-crystal measurements. The crystal structure of Ca(6)(C(12)H(14)O(4))(4)(CO(3))(OH)(2)(H(2)O)(14) is tetragonal, space group I4(1)/amd (141) with a = 29.12 Å, c = 15.85 Å, V = 13,440 Å(3) and Z = 8. The compound is classified as a 3D inorganic hybrid material with a 3-dimensional inorganic framework consisting of Ca and O, connected to 1,3-adamantanedicarboxylate anions. The structure shows hydrophilic channels in a diamond-like network. In between the channels there exist hydrophobic pores with surfaces defined by adamantane cages. The shortest distance between hydrogen atoms from different molecules in these pores is 3.6 Å. The largest hydrophilic cavity has a diameter of 10 Å and the pores connecting the channels have a diameter of 5 Å. In the as-synthesised state these channels are filled with water molecules. Reversible dehydration-rehydration occurs. The dehydrated compound easily takes up water from ambient air.
Department of Chemistry, University of Oslo, P.O. Box 1033 Blindern, N-0315 Oslo, Norway.
Renie Birkedal
RB
Nielsen
Poul
P
Norby
Kjell Ove
KO
Kongshaug
Helmer
H
Fjellvåg