Sulfur imides

The sulfur imides are a group of sulfur - nitrogen compounds with the general composition S _x (NH) _y . They are derived from sulfur rings S _x , with individual sulfur atoms being replaced by imide groups NH. This only results in compounds in which one imide group is always bound to two sulfur atoms. Formally, they can be seen as reduced forms of sulfur nitrides . A heptasulphurimide, three hexasulphurimides, two pentasulphuretriimides and one tetrasulphuretraimide are derived from the sulfur ring S ₈ .

Known sulfur imides S _x (NH) _y with x + y = 8

Surname	formula	Structural formula	CAS number	molar mass	Melting point	Remarks
Tetrasulfur-1,3,5,7-tetraimide	S 4 (NH) 4		293-40-3	188.323 g mol −1	145 ° C
Pentasulfur-1,3,5-triimide	S 5 (NH) 3		638-50-6	205.374 g mol −1	128 ° C	colorless solid
Pentasulfur-1,3,6-triimide	S 5 (NH) 3		334-35-0	205.374 g mol −1	133 ° C	colorless solid
Hexasulfur-1,3-diimide	S 6 (NH) 2		1003-75-4	222.425 g mol −1	130 ° C	colorless solid
Hexasulfur-1,4-diimide	S 6 (NH) 2		1003-76-5	222.425 g mol −1	133 ° C	colorless solid
Hexasulfur-1,5-diimide	S 6 (NH) 2		3925-67-5	222.425 g mol −1	155 ° C	colorless solid
Heptasulfurimide	S 7 NH		293-42-5	239.77 g mol −1	113.5 ° C	pale yellow solid

The heptasulfurimide is produced by the reaction of sulfur with sodium azide in hexamethylphosphoric acid triamide . This initially results in a sodium salt, the protolysis of which leads to the free imide.

${\displaystyle \mathrm {{7/8}\ S_{8}+NaN_{3}\longrightarrow N_{2}+S_{7}N^{-}Na^{+}{\xrightarrow {H^{+}}}\ S_{7}NH} }$

The tetrasulfur-1,3,5,7-tetraimide can be produced by the reduction of tetrasulfur-tetranitride with tin (II) -chloride and methanol .

${\displaystyle \mathrm {S_{4}N_{4}{\xrightarrow {SnCl_{2}/CH_{3}OH}}\ S_{4}(NH)_{4}} }$

The other eight-membered sulfur imides result as a mixture through the reaction of ammonia with sulfur dichloride or disulfur dichloride or of tetrasulfur tetraimide with sulfur S ₈ .

There are other sulfur imides which are derived from other sulfur rings, such as S ₆ , S ₉ , S ₁₀ and S _12, by replacing individual S atoms with NH. Example compounds here are the S ₄ (NH) ₂ , the S ₈ NH, the S ₉ NH and S ₁₁ NH.

Individual evidence

1. ↑ ^{a b c d e} Wiberg, E .; Wiberg, N .; Holleman, AF : Inorganische Chemie , 103rd edition, 2017 Walter de Gruyter GmbH & Co. KG, Berlin / Boston, ISBN 978-3-11-026932-1 , pp. 679-680, (accessed via De Gruyter Online).
2. ↑ Large sulfur-nitrogen heterocycles: Synthesis of the sulfur imides SnNH (n = 8, 9, 11) and structures of S8NH and S9NH . In: Angewandte Chemie . tape 108 , no. 21 , November 6, 1996, pp. 2641-2643 , doi : 10.1002 / anie.19961082111 .

literature

• Garcia-Fernandez, H .; Coudanne, H .; Pindat, MA: Phosphorus, Sulfur and Silicon and the Related Elements Vol. 41 (1989) 405-418.