Copper benzoate

Copper benzoate
Names
	IUPAC name copper dibenzoate
	Other names cupric benzoate
Identifiers
CAS Number	533-01-7 ;
3D model (JSmol)	Interactive image; Chinese lantern structure: Interactive image;
ChemSpider	144339 ;
ECHA InfoCard	100.007.776
PubChem CID	164650;
UNII	1M9U62M4WK ;
CompTox Dashboard (EPA)	DTXSID20890501 ;
	InChI InChI=1S/2C7H6O2.Cu/c28-7(9)6-4-2-1-3-5-6;/h21-5H,(H,8,9);/q;;+2/p-2 Key: YEOCHZFPBYUXMC-UHFFFAOYSA-L ; InChI=1/2C7H6O2.Cu/c28-7(9)6-4-2-1-3-5-6;/h21-5H,(H,8,9);/q;;+2/p-2 Key: YEOCHZFPBYUXMC-NUQVWONBAX;
	SMILES [Cu+2].[O-]C(=O)c1ccccc1.[O-]C(=O)c1ccccc1; Chinese lantern structure: c0ccccc0[C-](O[Cu+2]123)O[Cu+2](O[C-](O1)c0ccccc0)(O[C-](O2)c0ccccc0)O[C-](O3)c0ccccc0;
Properties
Chemical formula	C14H10CuO4
Molar mass	305.7728 g/mol
Appearance	blue solid
Density	1.197g/cm3
Hazards
Flash point	111.4 °C (232.5 °F; 384.5 K)
	NIOSH (US health exposure limits):
PEL (Permissible)	TWA 1 mg/m3 (as Cu)
REL (Recommended)	TWA 1 mg/m3 (as Cu)
IDLH (Immediate danger)	TWA 100 mg/m3 (as Cu)
Related compounds
Other cations	sodium benzoate
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). verify (what is ?) Infobox references

Copper benzoate is the chemical compounds with the formula Cu(C₆H₅CO₂)₂(H₂O)_x. These coordination complexes are derived from the cupric ion and the conjugate base of benzoic acid. Many derivatives are known with diverse ancillary ligands. This compound has found some use as a source of blue light in fireworks.

Preparation

In laboratory, copper benzoate can be made by combining aqueous solutions of potassium benzoate with copper sulfate. Hydrated copper benzoate precipitates as a pale blue solid:

4 C₆H₅CO₂K + 2 CuSO₄·5H₂O → Cu₂(C₆H₅CO₂)₄(H₂O)₂ + 2 K₂SO₄ + 8 H₂O

The primary use of this compound is in the production of a blue flame in fireworks. Copper benzoate made from sodium benzoate for use in fireworks may result in strong yellow dilution of the flame unless the precipitate is carefully washed to remove sodium ions (which emit bright yellow). Emission from potassium does not complicate the emission spectrum.^[2]

Structure

Copper(II) benzoate exists in at least two structural forms, depending on the degree of hydration. As in copper(II) acetate, one form of copper benzoate adopts a "Chinese lantern" structure,^[3] wherein a pair of copper centers are linked by four bridging carboxylate ligands. Typically, one site on each copper center is occupied by water, which can be replaced by other ligands.^[4] A hydrated form is also known, wherein each Cu(II) centre is bound to four water ligands and a bidentate O,O-benzoate.^[5]

Related compounds

References

^ ^a ^b ^c NIOSH Pocket Guide to Chemical Hazards. "#0150". National Institute for Occupational Safety and Health (NIOSH).
^ "Wouter's Practical Pyrotechnics page". Archived from the original on 2007-01-07.
^ Wells, A.F. (1984) Structural Inorganic Chemistry, Oxford: Clarendon Press. ISBN 0-19-855370-6.
^ T. Kawata, H. Uekusa, S. Ohba, T. Furukawa, T. Tokii, Y. Muto, M. Kato "Magneto-structural correlation in dimeric copper(II) benzoates" Acta Crystallogr. 1992, vol. B48, pp. 253-261. doi:10.1107/S0108768191012697
^ Koizumi, Hideo; Osaki, Kenji; Watanabé, Tokunosuké (1963). "Crystal Structure of Cupric Benzoate Trihydrate Cu(C₆H₅COO)₂3H₂O". Journal of the Physical Society of Japan. 18 (1): 117–124. Bibcode:1963JPSJ...18..117K. doi:10.1143/JPSJ.18.117.

[PGCH-1] NIOSH Pocket Guide to Chemical Hazards. "#0150". National Institute for Occupational Safety and Health (NIOSH).

[2] "Wouter's Practical Pyrotechnics page". Archived from the original on 2007-01-07.

[3] Wells, A.F. (1984) Structural Inorganic Chemistry, Oxford: Clarendon Press. ISBN 0-19-855370-6.

[4] T. Kawata, H. Uekusa, S. Ohba, T. Furukawa, T. Tokii, Y. Muto, M. Kato "Magneto-structural correlation in dimeric copper(II) benzoates" Acta Crystallogr. 1992, vol. B48, pp. 253-261. doi:10.1107/S0108768191012697

[5] Koizumi, Hideo; Osaki, Kenji; Watanabé, Tokunosuké (1963). "Crystal Structure of Cupric Benzoate Trihydrate Cu(C₆H₅COO)₂3H₂O". Journal of the Physical Society of Japan. 18 (1): 117–124. Bibcode:1963JPSJ...18..117K. doi:10.1143/JPSJ.18.117.

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