10.1107/S0108270111043083
The research investigates the crystallization behavior of the compound C11H11SN3, which forms twins with a twin volume fraction of 0.4232 (13). The study aims to provide a plausible explanation for this behavior using the order–disorder (OD) theory, which was originally developed in the 1950s to explain unusual X-ray diffraction effects in minerals and inorganic compounds. The compound crystallizes in a polytype with a maximum degree of order (MDO), and the contact plane is interpreted as being composed of a fragment of the second MDO polytype. The researchers synthesized the title compound through a series of chemical reactions involving (3-bromo-2-thienyl)trimethylsilane, azidobenzene, and other reagents, and characterized it using NMR and mass spectrometry. The crystal structure was determined using X-ray diffraction, revealing that molecules are connected via C—H…N hydrogen bonds, forming layers parallel to (100). The study concludes that the observed twinning can be explained by the geometric equivalence of layers according to OD theory, with the structure belonging to an OD family characterized by two kinds of nonpolar layers. This work contributes to the understanding of polytypism and twinning in organic compounds and highlights the applicability of OD theory to explain such phenomena.
10.1002/hlca.19800630641
The research explored the 1,3-dipolar additions to 7-methylthieno[2,3-c]pyridine 1,1-dioxide. The study aimed to investigate the influence of the condensed pyridine ring on the orientation of the addition and the stability of the resulting primary products. Various 1,3-dipoles, including diazomethane, diazoethane, ethyl diazoacetate, phenyldiazomethane, and phenyl azide, were reacted with the target compound. The primary products were characterized using spectroscopic techniques, and their behavior under elevated temperatures and basic conditions was examined. The findings revealed that these products could undergo transformations such as loss of SO2 or N2 under certain conditions, leading to the formation of different compounds like pyrazoles and cyclopropanes.