Directional koilates

For the geometrically differentiated noncentrosymmetric koiland 22 based on the double fusion of the p-tert-butyl calix 5 and p-allyl calix unit 6 by two Si atoms, the formation of directional koilates was studied using p-xylene 31 as a centrosymmetric (Figure 4g and h) and phenylpropyne 34 as a noncentrosymmetric (Figure 4f) connectors [81]. 

Figure 18 A portion of the X-ray structure of the koilate formed between the mono fused koiland 23 and hexadiyne 33 as connector. The directional 1-D network is obtained by a single translation in a noncentric fashion of two different assembling cores defined by the inclusion of the connector into the two differentiated cavities of the koiland (a) and a portion of the structure showing the centrosymmetric packing of consecutive directional koilates leading to a nonpolar solid (b). For the sake of clarity, the carbon atoms of the connector are coloured in grey and the hydrogen atoms are not represented.

Hosseini, M.W. De Cian. A. Molecular tectonics An approach to organic networks. Chem. Commun. 1998. 727. Martr. J. Graf E. Hosseini. M.W. De Cian. A. Fischer. J. Directional 1-D inclusion networks Self-assembly of unsymmetrical koilands into directional koilates in the crystalline phase. 3. Chem. Soc. Dalton Trans. 2000. 3791. Braga. D. Maini. L. Grepioni. F. Mota. F. Rovira. C. Novoa, J.J. Inter-anionic O-H-.-O interactions A... 

The formation of directional 1-D koilates based on self-inclusion was also investigated. The self-complementary koiland 16 based on the double fusion of the calix derivatives 1 and 2 by two Si atoms was found to generate a selfinclusion network (Figure 21). However, the koilate formed was not directional because the self-inclusion processes, leading to the formation of the network, take... 

Two calix[4]arenes may be connected also by a spiro-linker derived from pentaerythritol (D with X = — (CH2)20(CH2)20CH2—) ° or by two tetravalent atoms (E, X = Si, Ti). In the latter case, centro-symmetric molecules with two open cavities pointing in opposite directions (koilands) are obtained (SiCLt, NaH, THF, 52%) and may form one-dimensional networks in the crystalline state (koilates) when a suitable connector (e.g. hexadiyne) is included in their cavities. ... 

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