Reversible Photocontrol of the Coordination Number of Silicon in a Tetrafluorosilicate Bearing a 2-(Phenylazo)phenyl Group

Abstract

Experimental SectionGeneral Procedure. All melting points are uncorrected. Solvents were purified before use by reported methods. All reactions were carried out under argon atmosphere unless otherwise noted. The 1 H NMR (500 MHz), 13 C NMR (125 MHz), 29 Si NMR (99 MHz) spectra were measured with a JEOL A500 spectrometer using tetramethylsilane (TMS) as internal standard. The 19 F NMR (254 MHz) spectra were taken with a JEOL EXcalibur270 spectrometer using Fleon ® as external standard. Elemental analyses were performed by the

Synthesis of Amines from Imines in the Coordination Sphere of Silicon—Surprising Photo‐Rearrangement of Hexacoordinate Organosilanes

“…Previous investigations on the photoreactivity of complexes with hypercoordinate silicon atom resulted in photo‐switching of the coordination number at the Si atom by UV‐induced trans‐ ‐ cis isomerization of diazobenzene ligands 6. Our photoreaction presented herein provides a new synthetic route to amines.…”

Synthese von Aminen aus Iminen in der Koordinationssphäre von Silicium – eine überraschende Photoumlagerung von hexakoordinierten Organosilanen

“…Bisherige Untersuchungen zu Photoreaktionen von Komplexen mit hyperkoordinierten Si-Atomen zeigten die Photoschaltbarkeit der Koordinationszahl über UV-induzierte trans-cis-Isomerisierung von Diazobenzolliganden. [6] Die hier vorgestellte Photoreaktion eröffnet einen neuen Syntheseweg für Amine. Diese Umlagerung verkörpert eine neuartige Organylierung mit siliciumorganischen Verbindungen.…”

Heteroatom chemistry in Asia: Past, present, and future

“…Hexacoordinated tetrafluorosilicate (E)-46 was obtained by treatment of 45 with KF in the presence of 18-crown-6 at room temperature. Interconversion between (E)-46 with coordination number 6 and (Z)-46 with coordination number 5 was achieved under irradiation at 360 and 431 nm (Scheme 17) [69]. We could isolate both isomers and obtain single crystals suitable for X-ray crystal analysis.…”

“…Initially, silicon compounds are described. We synthesized 2-trifluorosilylazobenzene (45), which was shown to have a pentacoordinated silicon both in solution and in the solid state by variable-temperature NMR and X-ray crystallographic analysis [69]. Hexacoordinated tetrafluorosilicate (E)-46 was obtained by treatment of 45 with KF in the presence of 18-crown-6 at room temperature.…”

“…We could isolate both isomers and obtain single crystals suitable for X-ray crystal analysis. X-ray crystallographic analysis showed that (E)-46 has an octahedral structure consisting of four fluorine, one nitrogen, and one carbon atoms, where the nitrogen and carbon atoms are cis to each other, while (Z)-46 has a trigonal bipyramidal structure consisting of four fluorine and one carbon atoms, where two fluorine atoms occupy the apical positions, because the nitrogen of the azo group can no longer coordinate to the silicon in (Z)-46 [69].…”