Reactions of Silicon Atoms with Benzene: A Matrix‐Spectroscopic Study

Abstract

The reaction of silicon atoms with benzene in argon at 10 K has been studied. The addition to the aromatic π‐system of benzene occurs in a [1,4]‐fashion. Upon irradiation the π‐adduct 7‐silabicyclo[2.2.1]heptadien‐7‐ylidene (2) rearranges to the formal C−C insertion product 1‐silacycloheptatrienylidene (3). The structural elucidation of the new species is based on comparison of the experimental observations with density functional calculations. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)

Formation of 1-ethynyl-1H-silole from the reaction of silicon atoms with benzene: matrix infrared spectroscopy and quantum chemical calculations

“…It is noteworthy that it was not possible to convert A completely into B under 313 nm light irradiation for 3 h, and longer irradiation did not lead to a higher amount of B in a previous experiment. 28 Although the broadband irradiation in the wavelength range of 280 nm o l o 580 nm and only 15 minutes of irradiation were utilized, species B was still observed in our experiment. As shown in Tables S1 and S2 (ESI †), these absorptions are in good agreement with the prediction vibration frequencies and the previous assignment of 1silacycloheptatrienylidene in solid argon.…”

“…The Si(C 6 H 6 ) in solid argon. 28 Quantum chemical calculations at the B3LYP/aug-cc-pVTZ level were performed to interpret the experimental vibrational features. It is apparent that the predicted Si[Z 2 (1,4)-C 6 H 6 ] vibration frequencies show excellent agreement with the experimental spectrum (shown in Tables S1 and S2, ESI †).…”

“…25 Meanwhile several silicon-containing heterocyclic compounds have been synthesized in the reactions of silicon atoms with conjugated p-systems through the matrix isolation method and they have been characterized by their IR or UV-vis spectra. [26][27][28][29] Although the thermally generated silicon atoms could insert into the C-C bond of benzene to form a seven-membered ring 1-silacycloheptatrienylidene as the final product via a Z 2 -p adduct intermediate upon irradiation in solid argon, no silole derivatives were observed in the reaction of silicon atoms with benzene (as shown in Scheme 1). 28 Boron atoms can be spontaneously and selectively inserted into the C-C bond forming the borepine radical and further photo-isomerization to five-membered borole derivatives, during the reaction of boron atoms with a benzene molecule under matrix isolated conditions.…”

“…[26][27][28][29] Although the thermally generated silicon atoms could insert into the C-C bond of benzene to form a seven-membered ring 1-silacycloheptatrienylidene as the final product via a Z 2 -p adduct intermediate upon irradiation in solid argon, no silole derivatives were observed in the reaction of silicon atoms with benzene (as shown in Scheme 1). 28 Boron atoms can be spontaneously and selectively inserted into the C-C bond forming the borepine radical and further photo-isomerization to five-membered borole derivatives, during the reaction of boron atoms with a benzene molecule under matrix isolated conditions. 30 Due to its small size and similar charge/mass ratio, boron is different to other group 13 members, but it resembles silicon, the second element of group 14 and they exhibit a diagonal relationship.…”

Interplay of thermochemistry and structural chemistry, the journal (volume 24, 2013, issues 5–6) and the discipline

“…The calculated binding energy and charge transfer from the Li to the Si: graphene system were estimated to be -2.01 eV and 0.94 e, respectively. As shown by matrix isolation studies, atomic silicon combines with benzene by 1,4-addition, and this product rearranges thermally to the more stable 7-membered ring isomer [42]. By contrast, the most stable isomer of C 6 H 6 Si ?…”