%0 Journal Article %1 Mondal.2013b %A Mondal, Kartik Chandra %A Roesky, Herbert W. %A Stueckl, A. Claudia %A Ehret, Fabian %A Kaim, Wolfgang %A Dittrich, Birger %A Maity, Bholanath %A Koley, Debasis. %D 2013 %J Angewandte Chemie, International Edition %K EPR alkyl amino carbene crystal cyclic prepn radical radical;mol structure structure;magnetic susceptibility trichlorosilyl %N 45 %P 11804--11807 %R 10.1002/anie.201300668 %T Formation of Trichlorosilyl-Substituted Carbon-Centered Stable Radicals through the Use of p-Accepting Carbenes %V 52 %X Authors have systematically studied the chem. behavior of cyclic alkyl(amino)carbenes (cAAC) toward SiCl4. It found that the cAAC carbene forms zwitterionic adducts cAAC$\rightarrow$SiCl4, confirmed from x-ray diffraction. The zwitterionic nature of these adducts is responsible for their poor soly. in nonpolar solvents. The adducts are converted into stable and isolable trichlorosilylcarbene radicals (cAAC·)SiCl3 4a and 4b through KC8 redn. As a consequence, the bond between the silicon atom and the carbene carbon atom dramatically changes its nature from a coordinate bond in 3a and 3b to a covalent bond in 4a and 4b. Such behavior of cAACs has no precedence in NHCs. Thus, the adjustable bonding nature between the electron-donating cAAC and the acceptor opens up another route toward the generation of a radical center just next to an acceptor with the general formula (cAAC·)m-EXn E = metal or metalloid; n = 0, 1, 2, 3, m = 1, 2, 3, etc.; X = halide, R, etc., which will find important chem. applications in the future. Moreover, compd. 4b was characterized in two polymorphic solid state forms. Compds. 4a and 4b are mono radicals, as confirmed by bulk magnetic susceptibility measurements in the solid state, EPR spectroscopy, and DFT calcns. on SciFinder(R)

@article{Mondal.2013b, abstract = {Authors have systematically studied the chem. behavior of cyclic alkyl(amino)carbenes (cAAC) toward SiCl4. It found that the cAAC carbene forms zwitterionic adducts cAAC$\rightarrow$SiCl4, confirmed from x-ray diffraction. The zwitterionic nature of these adducts is responsible for their poor soly. in nonpolar solvents. The adducts are converted into stable and isolable trichlorosilylcarbene radicals (cAAC·)SiCl3 4a and 4b through KC8 redn. As a consequence, the bond between the silicon atom and the carbene carbon atom dramatically changes its nature from a coordinate bond in 3a and 3b to a covalent bond in 4a and 4b. Such behavior of cAACs has no precedence in NHCs. Thus, the adjustable bonding nature between the electron-donating cAAC and the acceptor opens up another route toward the generation of a radical center just next to an acceptor with the general formula (cAAC·)m-EXn [E = metal or metalloid; n = 0, 1, 2, 3, m = 1, 2, 3, etc.; X = halide, R, etc.], which will find important chem. applications in the future. Moreover, compd. 4b was characterized in two polymorphic solid state forms. Compds. 4a and 4b are mono radicals, as confirmed by bulk magnetic susceptibility measurements in the solid state, EPR spectroscopy, and DFT calcns. [on SciFinder(R)]}, added-at = {2019-07-15T13:41:23.000+0200}, author = {Mondal, Kartik Chandra and Roesky, Herbert W. and Stueckl, A. Claudia and Ehret, Fabian and Kaim, Wolfgang and Dittrich, Birger and Maity, Bholanath and Koley, Debasis.}, biburl = {https://puma.ub.uni-stuttgart.de/bibtex/281b082830deabb9d0dc5ac92b20d2b23/b_schwederski}, doi = {10.1002/anie.201300668}, interhash = {f84058d000d5d9359b7f947b6f435554}, intrahash = {81b082830deabb9d0dc5ac92b20d2b23}, issn = {1433-7851}, journal = {Angewandte Chemie, International Edition}, keywords = {EPR alkyl amino carbene crystal cyclic prepn radical radical;mol structure structure;magnetic susceptibility trichlorosilyl}, number = 45, pages = {11804--11807}, timestamp = {2019-07-15T11:42:10.000+0200}, title = {Formation of Trichlorosilyl-Substituted Carbon-Centered Stable Radicals through the Use of \textgreek{p}-Accepting Carbenes}, volume = 52, year = 2013 }