“Sulflower”: A New Form of Carbon Sulfide
(Angew. Chem. Int. Ed. 2006， 45， 7367)
The bloom of a sunflower is used to describe the highly symmetric planar structure of octathiocirculene, whose trivial name “sulflower” derives from sulfur and flower (see cover picture). In their Communication on page 7367 ff., V. G. Nenajdenko and co-workers describe the synthesis and characterization of sulflower, a molecule that can be considered as a new form of carbon sulfide and as an oligothiophene, that is, as both inorganic and organic. (Background picture: “Sunflowers” by Vincent van Gogh. Copyright: Neue Pinakothek, Munich.)
|Konstantin Yu. Chernichenko, Viktor V. Sumerin, Roman V. Shpanchenko, Dr., Elizabeth S. Balenkova, Prof. Dr., Valentine G. Nenajdenko, Prof. Dr. *|
|Department of Chemistry, Moscow State University, Leninskiye Gory, 119992 Moscow, Russia, Fax: (+7) 495-932-8846|
|email: Valentine G. Nenajdenko (firstname.lastname@example.org)|
Molecular formula: C16S8
8-fold rotational symmetry
Left: Sunflowers by Vincent van Gogh (Copyright, Neue Pinakothek, Munich). Right: Types of annulated oligothiophenes: sulflower (1), linear 2, helical 3, and circulenic 4.
Oriented by theoretical calculation:
Calculated strain and geometries for fully thiophenic circulenes (n=number of thiophene rings). S yellow, C gray.
Concise and dream-like synthetical route:
Synthesis of circulene 1 from tetrathiophene 5 via polythiole 6 (n=1). Reagents and conditions: a) LDA (16 equiv), sulfur (16 equiv), room temperature, 24 h; b) aq. HCl; c) vacuum pyrolysis.
Unambiguous structural determination:
Packing of sulflower (1) molecules in the unit cell. S yellow, C white.