Crystal structure of N,N '-dipropylsuberamide and N,N '-dipropylsebacamide as a packing model of the alpha-form of even-even nylons

摘要

The crystal structures of N,N'-dipropylsuberamide (pSUp) and N,N'-dipropylsebacamide (pSEp) have been investigated by X-ray diffraction. These compounds crystallized in the triclinic system. space group P (1) over bar with a = 4.910(2) Angstrom, b = 5.375(1) Angstrom, c = 16.90(2) Angstrom, alpha = 91.16(10)degrees, beta = 91.70(7)degrees and gamma = 115.80(8)degrees for pSUp, and a = 4.9215(11) Angstrom, b = 5.3948(9) Angstrom, c = 18,745(9) Angstrom, alpha = 85.79(3)degrees, beta = 86.70(3)degrees and gamma = 64.41(2)degrees for pSEp. The crystal structures have been solved by direct methods and refined using the full least squares methodology. Final R values were 0.0888 and 0.1297 for pSUp and pSEp, respectively. Analysis of the structures showed the features of the extended alpha-form of even-even polyamides and so accurate data concerning the molecular conformation. the setting orientation of molecules and the relative shiftings between neighbouring chains could be obtained From models. References: 22