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The binuclear nitrosyl complexes Q2[Fe2S2(NO)4], where Q = Me, Et, Pr n. and Bu n, were synthesized. The crystals of [Pr]N 12Fe2S2(NO)a were studied by X-ray analysis. The influence of the cation size on the electronic structure and symmetry of its local environment in the synthesized complexes was examined. The decrease in the isomeric shifts in the 57Fe Mbssbauer spectra is related to the increase in the length of the alkyt substituent chain of the quaternary tetraammonium cation and is consistent with changing the structural parameters: a decrease in the bond angle of the Fe--NO bond and stretching vibrations of the NO groups due to changes in intermolecular contacts.

Six indolinospironaphthoxazines were studied by X-ray diffraction analysis. It was demonstrated that the electronic nature of the substituents in the naohthoxazine and indoline fragments has no substantial effect on the Csoiro--O and Cspiro--N bond lengths. Photocolorability of the compounds under study depends only slightly on the abovementioned bond lengths and correlates mainly with the energy of steric strain of the oxazine ring. The stability of the open forms of spiroindolinonaphthoxazines that formed upon photoirradiation is determined to a large extent by the electronic and steric nature of the substituents. The exception is the compound that contains the NO 2 group in the indoline fragment. In the last-mentioned case, the cleavage of the ring occurs through a substantially different pathway.