Double pancake versus long chalcogen-chalcogen bonds in six-membered C,N,S-heterocycles

Abstract The double ?pancake? bonding in the dimers of the six-membered heterocycles 1,3-dithia-2,4,6-triazine (4) and 1,3-dithia-2,4-diazine (16) were investigated by means of high-level quantum chemical calculations (B3LYP and CCSD(T)). It was found that the S?S dimers, 20?a and 27, are not the mo...

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Hauptverfasser: Haberhauer, Gebhard (VerfasserIn) , Gleiter, Rolf (VerfasserIn)
Dokumenttyp: Article (Journal)
Sprache:Englisch
Veröffentlicht: 12 May 2016
In: Chemistry - a European journal
Year: 2016, Jahrgang: 22, Heft: 25, Pages: 8646-8653
ISSN:1521-3765
DOI:10.1002/chem.201601121
Online-Zugang:Verlag, lizenzpflichtig, Volltext: https://doi.org/10.1002/chem.201601121
Verlag, lizenzpflichtig, Volltext: https://chemistry-europe.onlinelibrary.wiley.com/doi/full/10.1002/chem.201601121
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Verfasserangaben:Gebhard Haberhauer and Rolf Gleiter
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Zusammenfassung:Abstract The double ?pancake? bonding in the dimers of the six-membered heterocycles 1,3-dithia-2,4,6-triazine (4) and 1,3-dithia-2,4-diazine (16) were investigated by means of high-level quantum chemical calculations (B3LYP and CCSD(T)). It was found that the S?S dimers, 20?a and 27, are not the most stable isomers, but the dimers showing short S?N (21?a) and S?C (25, 28) bonds. An investigation of the 5-phenyl-1,3-dithia-2,4,6-triazine (4?b) yields that the syn dimer with two S?S bonds (2.57?Å) is the most stable one. In this dimer, the phenyl groups are placed on top of each other. The additional dispersion energy of the phenyl rings causes a stabilization of the syn-S?S (C2v-like) isomer. As a result, two weak albeit relevant single S?S bonds (2.57?Å) are predicted. These findings contradict the recently published concept of double ?pancake? bonding in the dimer 4?b2.
Beschreibung:Gesehen am 28.08.2020
Beschreibung:Online Resource
ISSN:1521-3765
DOI:10.1002/chem.201601121