Engel’s sulfur

Sulfur can form rings and chains of various shapes and sizes. In addition to the crown-shaped cyclo-Sg, nine other types of rings can be prepared the first of these, cyclohexasulfur, also called Engel s or Aten s sulfur, or rhombohedral sulfur, Sp, was first described by Engel in 1891 (28). The other eight types of rings were all discovered during the last 10 years by Schmidt and his co-workers (87,88) notably Wilhelm (125). 

We now consider other homocyclic polymorphs of sulfur containing 6 - 20 S atoms per ring. A rhombohedral form, t-sulfur, was first prepared by M. R. Engel in 1891 by the reaction of concentrated HCl on a saturated solution of thiosulfate HS2O3 at 0°. It was shown to be... 

Rhombohedral sulfur Aten sulfur Engel sulfur e-Sulfur p-Sulfur Rhombohedral (p) sulfur Crystalline cyclo-S Space group R3... 

Engel, R., Rengan, K, Chan, C.-s. (1993a). Phosphorus Cascade Molecules, Phosphorus and Sulfur, Vol. 77, p. 221, ISSN 1042-6507. 

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