PHTP (the fully trans isomer of perhydrotriphenylene is a host substance for many different inclusion compounds. The X-ray crystal structure of the PHTP-n-heptane adduct is described in detail; it must be considered as a representative term of a large isomorphous series, where both linear polymers (polyethylene, polyoxyethylene, cis- and trans-1,4 polybutadiene...) and small linear molecules (n-hydrocarbons, n-ethers, n-carboxylic acids...), and also some more bulky molecules (iso-octane, CCl4) may be included. The host structure consists of stacks of superimposed molecules, leaving a hexagonal pattern of nearly cylindrical channels, to be filled by the guest substance (a = b = 14.40; c = 4.78 Å; sp. group P63/m). The above picture is substantially unvaried for all the PHTP inclusion compounds, even if more complex structures have been observed (see Notes II and III of this series of papers). The same is true for a kind of statistical disorder, consisting in the mutual substitution of d and l molecules in the same crystal sites. From the characteristic streaks appearing in the X-ray spectra the channel periodicity among n-hydrocarbon molecules has been determined from C5 to C32; there results that the small molecules are appreciably twisted, tending to the characteristic planar shape with increasing molecular weight.
Referenze Bibliografiche
[1] G. ALLEGRA, M. FARINA, A. IMMIRZI, A. COLOMBO, U. ROSSI, R. BROGGI, G. NATTA, «J. Chem. Soc.», in corso di stampa.
[2] G. ALLEGRA, M. FARINA, A. COLOMBO, G. CASAGRANDE TETTAMANTI, U. ROSSI, G. NATTA, «J. Chem. Soc.», in corso di stampa.
[3] M. FARINA, Tetrahedron Letters, 2097 (1963).
[4] M. FARINA, G. ALLEGRA, G. NATTA, «J. Am. Chem. Soc.», 86, 516 (1964).
[5] M. FARINA, G. NATTA, G. ALLEGRA, M. LÖFFELHOLZ, Estratti del Simposio Internazionale di Chimica Macromolecolare, Praga 1965 (P. 493); «J. Polymer Sci.», Parte C, in corso di stampa.
[6] D. LAWTON, H. M. POWELL, «J. Chem. Soc.», 2339 (1958).
[7] W. SCHLENK Jr., «Fortschr. Chem. Forsch.», 2, 92 (1951).
[8] Intern. Tables for X-ray Cryst., The Intern. Union of Cryst., Birmingham (1952), Vol. I.
[9]
L. PAULING,
The Nature of the Chemical Bond,
Cornell Univ. Press. Ithaca (N.Y.), (
1960), cap. VII. |
Zbl 0006.13702[10]
A. IMMIRZI,
G. ALLEGRA, «
Rend. Acc. Naz. Lincei»,
Nota II della stessa serie di lavori. |
fulltext bdim[11]
A. IMMIRZI,
G. ALLEGRA, «
Rend. Acc. Naz. Lincei»,
Nota III della stessa serie di lavori. |
fulltext bdim[12]
A. COLOMBO,
E. TORTI,
G. ALLEGRA, «
Rend. Accad. Naz. Lincei»,
Nota IV della stessa serie di lavori. |
fulltext bdim