Wyniki wyszukiwania - BazTech

Ograniczanie wyników

1 Polish Journal of Chemistry

1 1998

Znaleziono wyników: 1

Liczba wyników na stronie

Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych: quasiaromaticity

Sortuj według:

Ogranicz wyniki do:

The crystal and molecular structure of cyclic thioamide beta-dikotone derivatives. Intramolecular H-bonding and the problem of quasiaromaticity

Anulewicz R., Krygowski T.M., Jagodziński T.

Polish Journal of Chemistry

1998

Vol. 72, nr 2

439-448

Crystal and molecular structures of the 2,6-dioxocyclohexanethiocarboxanilide (I), 4,4-dimethyl-2,6-dioxocyclohexanethiocarboxanilide (II) and 1,3-indandione-2- thiocarboxanilide (III) have been determined by use of X-ray diffraction technique on a Kuma-diffractometer. Crystal data for compound (I): C13H13N1O2S1, M-r=247.32, monoclinic, C2/c, a=22.704(5)A, b=7.312(1)A, c=17.192(3)A, beta=123.07(3), Z=8, R=0.0597 for 2181 reflections. Compound (II): C15H17N1O2S1, M-r=275.36, triclinic, P-1, a=10.748(1)A, b=9.223(2)A, c=7.346(2)A, alpha=91.21(3), beta=100.36(3), gamma=76.01(3), Z=2, R=0.0733 for 2485 reflections. Compound (III): C16H11N1O2S1, M-r=281.12, triclinic, P-1, a=6.945(3)A, B=8.786(1)A, c=12.435(3)A, alpha=86.97(3), beta=73.78(3), gamma=66.74(3), Z=2,R=0,0696 for 2361 reflections. Of the two potentially H-bonding systems of each of the title compounds one that with OH...S, is stronger and this resilts in a stronger pi-electron delocalization. This is quantitatively measured by HOMA index, which is by ca. 0.3 units larger than for the other H-bonding system, the one with the NH...O bridge.