| Abstract: | 1-(4-Nitrobenzylidene)-pyrazolidone-(3)-betaine crystallizes in the orthorhombic space group Pbca with eight molecules per unit cell. The lattice parameters are a = 11.025 Å; b = 22.995 Å; c = 7. 677 Å. With X-ray diffraction data, collected on a automatical four circle diffractometer, the crystal structure was solved by direct methods and refined to an R-value of 0.047 for 1516 symmetrically independent reflections. The structure determination has been performed to contribute to the explanation of the photochromic behaviour of this special class of azomethine imines. |
