Coordination polymers classification

Hybrid framework compounds, including both metal-organic coordination polymers and systems that contain extended inorganic connectivity (extended inorganic hybrids), have recently developed into an important new class of solid-state materials. We examine the diversity of this complex class of materials, propose a simple but systematic classification, and explore the chemical and geometrical factors that influence their formation. We also discuss the growing evidence that many hybrid frameworks tend to form under thermodynamic rather than kinetic control when the synthesis is carried out under hydrothermal conditions. Finally, we explore the potential applications of hybrid frameworks in areas such as gas separations and storage,... 

Bilayer architectures formed in M2(2)3(N03)4 n (where M = Co, Ni and Zn) were one of the first systems of coordination polymers to be shown as porous materials [43]. The bilayer architectures interdigitate with each other leaving small channels in the crystal lattice which were occupied by solvated water molecules. Powder X-ray studies indicate that the water molecules can be removed from the network without causing any distortion or decomposition of the network. The adsorption studies of water removed and dried sample indicated that the material is capable of adsorbing CH4, N2 and 02. About 2.3 mmol of CH4 and 0.80 mmol of N2 or 02 are adsorbed per gram of anhydrous material. The adsorption-readsorption followed the same isotherm, indicating the stability of the network throughout the process. Further, the isotherms for the adsorption-readsorption can be classified as type I in the IUPAC classification [48]. 

Figure 7-14. Classification of interpenetrating coordination polymers a and b one-dimensional linear structures c and d two-dimensional interpenetration of ladders e and f three-dimensional interpenetration of undulating and multiple layers.

Pore Structure and Classification of Porous Coordination Polymers... 

Polymer complexes are composed of a metal complex bound to a chain of a linear macromolecule via a Type I coordinative bond, (see Section 1.2.1, Classification by Kind of Metal Complex/Metal Binding). The formation process of metal-polymer complexes can be schematically written as in Eq. (9-1), where M and X are a metal ion and its counter anion, respectively. 

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