Isofulgimides, characterized by a 5-iminodihydrofuran-2(3H)-one moiety, constitute a subgroup of fulgide derivatives that have received comparatively limited attention despite their potential photochromic applications. Herein, we report the synthesis, crystal structure, and preliminary photochromic characterization of a structurally unique dimeric isofulgimide in which two conjugated systems are connected through a single N–N bond to form a more extensively conjugated system. The compound crystallizes in the centrosymmetric triclinic space group P-1, with disorder of the phenyl groups in close intermolecular contact and strong interactions, including strong π-π stacking. the molecular structure of each half of the dimer closely superimposes on that of the starting fulgide. In solution, irradiation with a low-power 405 nm laser produced a new broad absorption band centered at approximately 510 nm, indicating photoinduced isomerization. After irradiation was discontinued, this band gradually disappeared within approximately 42 min, demonstrating thermal recovery of the initial form. Because isofulgimides remain relatively uncommon and crystallographic studies of dimeric isofulgimides have not previously been reported, these findings provide new structural and preliminary photochemical insights into this understudied class of photochromic compounds.

As the most abundant metalloids on earth boron and silicon play important roles in chemistry, allowing for the synthesis of a wide array of useful small molecules and materials. Fluoride is known to react with boron and silicon atoms. Fluoride etching of silicates is a common reaction with glass materials. Fluorides readily react with arylboronic acids to yield aryltrifluoroborates which are commonly in aromatic cross coupling reactions. Herein we explore fluoride exchange between potassium aryltrifloroborates and triethoxyphenylsilane. We further explore the fluorine exchange between different phenyl boronic acids and trifluorophenylsilane. NMR analysis allows us to conclude that fluoride favors the formation of bonds to boron while silicon preferentially bonds to oxides over fluoride. Finally, we demonstrate that this fluorine exchange can be used as a molecular template to cross couple aromatic rings at room temperature.

Fulgides are a class of organic compounds that have been extensively investigated because of their photochromic properties and the wide range of applications arising from them. Fulgimides, an important subclass of fulgides, contain a succinimide moiety in place of the succinic anhydride functionality found in fulgides. Isofulgimides are constitutional isomers of fulgimides in which the succinimide ring is replaced by a 5-iminodihydrofuran-2(3H)-one moiety. Although isofulgimides also exhibit photochromism, their synthesis and photochromic behavior have received considerably less attention than those of other fulgide derivatives. Reports on isofulgimides remain scarce, and crystallographic investigations are particularly limited. As part of our ongoing efforts to develop novel photochromic compounds, we synthesized a unique dimeric isofulgimide featuring an N–N single-bond linkage. Herein, we report its synthesis, crystal structure, and photochromic properties.