Chiral networks, interpenetration

While in most cases interpenetration occurs between identical networks, interpenetration of a heterogeneous nature is well known. This can involve interpenetration of chiral networks of opposite handedness, interpenetration of topologically identical but chemically different networks, or interpenetration of topologically (and even dimensionally) different networks. 

Fig. 5). Though they could isolate the product with desired network, the interpenetration led to almost closed-pack system. Later, through suitable selection of molecular building blocks and reaction condition, they synthesized a large number of chiral MOPMs with the same strategy. 

An alternative approach to catalytically active homochiral MOFs is to incorporate directly chiral metal complexes which are either active catalysts or precatalysts into the framework structures. For example, Hupp and coworkers have combined Ls and H2bpdc with Zn(N03)2 and obtained twofold interpenetrating 3D networks [Zn2G3pdc)2Ls]10DMF-8H2O (17) (Scheme 12) [46]. While the channels along... 

Kepert. C.J. Rosseinsky. M.J. A porous chiral framework of coordinated 1,3,5-benzenetricarboxylate Quadruple interpenetration of the (10.3)-a network. Chem. Commun. 1998. 31-32. 

The introduction of chirality into networks leads to another way that nets can interpenetrate in different ways. For example, the (10,3)-a net is inherently chiral, meaning that the interpenetrating nets may be of all the same handedness, of opposite handedness, or a combination of both (in equal or unequal numbers). Interpenetration of two (10,3)-a nets with either the same or the opposite handedness is shown in Figure 13. As examples, [Ni3(btc)2(pyridine)g(eg)g]. 3eg. 4H20, btc = benzene-... 

It was established that chitosan is diffusion selective, and CD is sorption selective in membrane-mediated resolution processes, therefore the combination of these two chiral separation types is promising. Having this in mind, the chitosan/[3-CD composite membranes of a semi-interpenetrating network were studied in the enantiomer separation of tryptophan (Trp) racemate, and the influence of CD content on the permselectivity and permeate flux of the CS/CD composite membrane was discussed [98]. 

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