Posts Tagged ‘Conjugated system’
Thursday, January 3rd, 2019
There is emerging interest in cyclic conjugated molecules that happen to have triplet spin states and which might be expected to follow a 4n rule for aromaticity.[1] The simplest such system would be the triplet state of cyclobutadiene, for which a non or anti-aromatic singlet state is always found to be lower in energy. Here I explore some crystal structures containing this motif for possible insights.
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References
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A. Kostenko, B. Tumanskii, Y. Kobayashi, M. Nakamoto, A. Sekiguchi, and Y. Apeloig, "Spectroscopic Observation of the Triplet Diradical State of a Cyclobutadiene", Angewandte Chemie International Edition, vol. 56, pp. 10183-10187, 2017. http://dx.doi.org/10.1002/anie.201705228
Tags:antiaromaticity, aromaticity, Baird's rule, Conjugated system, crystal structure search, energy, Hückel's rule, Interesting chemistry, Nature, Physical organic chemistry, Physical sciences, search query, Triplet state
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Thursday, December 1st, 2016
Following on from a search for long C-C bonds, here is the same repeated for C=C double bonds.
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Tags:Chemical bond, chemical bonding, Chemical nomenclature, Chemistry, Conjugated system, double bond, energy, Interesting chemistry, Nature, Nonmetal, Organic chemistry, Physical organic chemistry, search query, Substituent
Posted in crystal_structure_mining | 2 Comments »