Tin (II) oxide

Crystal structure
	__ Sn 2+ __ O 2−
Space group	P 4 / nmm (No. 129)
General
Surname	Tin (II) oxide
other names	Tin monoxide
Ratio formula	SnO
Brief description	dark brown, odorless solid
External identifiers / databases
EC number	244-499-5
ECHA InfoCard	100.040.439
PubChem	88989
ChemSpider	80298
Wikidata	Q204980
properties
Molar mass	134.7 g · mol -1
Physical state	firmly
density	6.45 g cm −3
Melting point	1080 ° C (after disproportionation to tin and tin dioxide)
solubility	practically insoluble in water
safety instructions
GHS labeling of hazardous substances	no GHS pictograms
	no GHS pictograms
H and P phrases	H: no H-phrases
	P: no P-phrases
	As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Tin (II) oxide is a metastable compound consisting of tin and oxygen . Above 300 ° C, SnO disproportionates to metallic tin and tin dioxide . Under certain circumstances metastable tin sesquioxide can also be formed during this decomposition .

Extraction and presentation

Tin (II) oxide can be obtained from tin (II) chloride via tin (II) oxide hydrate , which is dehydrated in an aqueous solution when heated for a long time.

It generally arises in the form of a hydrate SnO • H ₂ O (x <1) when a tin (II) salt solution is mixed with a little alkali hydroxide or aqueous ammonia as a colorless, flaky precipitate that is very sparingly soluble in water. When heated in the absence of air (e.g. in a stream of carbon dioxide ) it is dehydrated at 60–70 ° C to form blue-black tin (II) oxide (α-tin (II) oxide). If a suspension of SnO • xH ₂ O in aqueous ammonia is heated to 90–100 ° C in the presence of phosphinate, red tin (II) oxide (β-tin ( II) oxide), which converts into the more stable α form when heated, under pressure or by inoculation with α-tin (II) oxide. When heated to 250–425 ° C, α-SnO disproportionates over various mixed-valent tin oxides.

properties

Tin (II) oxide is a dark gray odorless solid that is practically insoluble in water and ethanol. Tin (II) oxide (hydrated or non-hydrated) dissolves both in acids and in alkaline solutions , so it shows amphoteric character (formation of tin (II) salts or stannates (II) ("stannites").

The literature describes three modifications of tin monoxide (SnO).

The generally known form is the black-blue SnO which crystallizes in the tetragonal PbO form. It is isotypic to α- lead (II) oxide and has the space group P 4 / nmm (space group no. 129) with the lattice parameters a = 3.800 Å and c = 4.836 Å and two formula units per unit cell . If the coarsely crystalline black-blue SnO is ground in a mortar, the color changes to brown.Template: room group / 129

Under normal conditions there is a metastable red modification with an orthorhombic structure up to 270 ° C. It has the space group Cmc 2 ₁ (No. 36) , the lattice parameters a = 5.005 Å, b = 5.746 Å, c = 11.05 Å and eight formula units per unit cell. This structure can be converted into the first modification by mechanical pressure or contact with SnO with an α-PbO structure.Template: room group / 36

Another red modification with an unknown structure is also described in the literature.

Tin monoxide: coarsely crystalline and ground.

use

Tin (II) oxide is used as a reducing agent , soft abrasive and in the manufacture of tin salts. It is also used in the manufacture of copper ruby glass and in lighting with UV light.

Individual evidence

↑ ^a ^b ^c ^d ^e ^f ^g ^h data sheet Tin (II) oxide, 99.9% (metals basis) from AlfaAesar, accessed on December 7, 2019 ( PDF )(JavaScript required) .
↑ G. Murken, M. Trömel: About the tin oxide, Sn2O3, formed during the disproportionation of SnO. In: Journal of Inorganic and General Chemistry. 397, 1973, p. 117, doi : 10.1002 / zaac.19733970204 .
↑ Georg Brauer (Ed.), With the collaboration of Marianne Baudler a . a .: Handbook of Preparative Inorganic Chemistry. 3rd, revised edition. Volume I, Ferdinand Enke, Stuttgart 1975, ISBN 3-432-02328-6 , p. 759.
^ ^A ^b Arnold F. Holleman, Nils Wiberg: Basics and main group elements . Walter de Gruyter GmbH & Co KG, 2016, ISBN 978-3-11-049585-0 , p. 1182 ( limited preview in Google Book search).
^ J. Köhler, J. Tong, R. Dinnebier, A. Simon: Crystal Structure and Electronic Structure of Red SnO. In: Journal for inorganic and general chemistry , 638, 2012, pp. 1970–1975, doi: 10.1002 / zaac.201200263 .

[alfa-1] ↑ ^a ^b ^c ^d ^e ^f ^g ^h data sheet Tin (II) oxide, 99.9% (metals basis) from AlfaAesar, accessed on December 7, 2019 ( PDF )(JavaScript required) .

[DOI10.1002/zaac.19733970204-2] G. Murken, M. Trömel: About the tin oxide, Sn2O3, formed during the disproportionation of SnO. In: Journal of Inorganic and General Chemistry. 397, 1973, p. 117, doi : 10.1002 / zaac.19733970204 .

[brauer-3] Georg Brauer (Ed.), With the collaboration of Marianne Baudler a . a .: Handbook of Preparative Inorganic Chemistry. 3rd, revised edition. Volume I, Ferdinand Enke, Stuttgart 1975, ISBN 3-432-02328-6 , p. 759.

[Arnold_F._Holleman,_Nils_Wiberg-4] A ^b Arnold F. Holleman, Nils Wiberg: Basics and main group elements . Walter de Gruyter GmbH & Co KG, 2016, ISBN 978-3-11-049585-0 , p. 1182 ( limited preview in Google Book search).

[5] J. Köhler, J. Tong, R. Dinnebier, A. Simon: Crystal Structure and Electronic Structure of Red SnO. In: Journal for inorganic and general chemistry , 638, 2012, pp. 1970–1975, doi: 10.1002 / zaac.201200263 .