resolver

Chapter 2 9
inorganic SBU can be connected by distinct ditopic linkers to afford various materials with
the same structural topology (so-called IRMOFs) featuring predetermined cavity size and
functions (Figure2.5).[25, 34]
Figure 2.4. Construction of the MOF-5 framework. Top, the Zn 4 O(CO 2 ) 6 cluster. Bottom, one of the
cavities in the MOF-5 framework. Reprinted by permission from Macmillan Publishers Ltd:
Nature, 402, 276-279, copyright 1999. [18]
Consideration on the chemical and geometric attributes of the essential SBUs and linkers can
afford prediction of the framework topology, and subsequently result in the design and targeted
synthesis of a new class of porous materials featuring robust structures and high porosity.
Transition-metal carboxylate clusters may serve as SBUs with different points of extension
varying from 3 to 66. [30] In addition to the typical octahedral zinc acetate cluster (Zn 4 O(CO 2 ) 6 ) as
SBU, one of the other metal cluster commonly employed as a build blocks in the MOF synthesis is
square bimetallic PW (M 2 (CO 2 ) 4 ) (Figure 2.6), in which four carboxylates are connected to two
metal centers. Each metal center is often capped by labile solvent molecules (such as H 2 O). A
typical example composed of such building blocks is the 3D porous framework [Cu 3 (BTC) 2 ] n (also
known as HKUST-1 [35] or MOF-199 [36] ) reported by Chui. et al. in 1999.