http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
A Reinvestigation of the Fragmentation of 2-Carbena-1,3-dioxolane by CASSCF and CASPT2 Calculations
Park, Bong-Jin,Hrovat, David A.,Borden, Weston Thatcher Korean Chemical Society 2004 Bulletin of the Korean Chemical Society Vol.25 No.2
In agreement with the results of previous MP2 calculations by Sauers, B3LYP, CASSCF, and CASPT2 calculations on the parent 2-carbena-1,3-dioxolane show that it fragments to ethylene plus $CO_2$ by a concerted pathway with only a small energy barrier. Not only is fragmentation via stepwise C-O bond cleavage computed to be a much higher energy pathway, but the singlet diradical that would be an intermediate along such a reaction path is not even computed to be a local minimum on the potential energy surface.
Formation of Ground State Triplet Diradicals from Annulated Rosarin Derivatives by Triprotonation
Fukuzumi, Shunichi,Ohkubo, Kei,Ishida, Masatoshi,Preihs, Christian,Chen, Bo,Borden, Weston Thatcher,Kim, Dongho,Sessler, Jonathan L. American Chemical Society 2015 JOURNAL OF THE AMERICAN CHEMICAL SOCIETY - Vol.137 No.31
<P>Annulated rosarins, β,β′-bridged hexaphyrin(1.0.1.0.1.0) derivatives <B>1</B>–<B>3</B>, are formally 24 π-electron antiaromatic species. At low temperature, rosarins <B>2</B> and <B>3</B> are readily triprotonated in the presence of trifluoroacetic acid in dichloromethane to produce ground state triplet diradicals, as inferred from electron paramagnetic resonance (EPR) spectral studies. From an analysis of the fine structure in the EPR spectrum of triprotonated rosarin <B>H</B><SUB><B>3</B></SUB><B>3</B><SUP><B>3+</B></SUP>, a distance of 3.6 Å between the two unpaired electrons was estimated. The temperature dependence of the singlet–triplet equilibrium was determined by means of an EPR titration. Support for these experimental findings came from calculations carried out at the (U)B3LYP/6-31G* level, which served to predict a very low-lying triplet state for the triprotonated form of a simplified model system <B>1</B>.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/jacsat/2015/jacsat.2015.137.issue-31/jacs.5b05309/production/images/medium/ja-2015-05309k_0008.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/ja5b05309'>ACS Electronic Supporting Info</A></P>