Copper benzoate
PhCO2.svg) | |
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| Names | |
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| IUPAC name
copper dibenzoate
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| Other names
cupric benzoate
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| Identifiers | |
3D model (JSmol)
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| ChemSpider | |
| ECHA InfoCard | 100.007.776 |
PubChem CID
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| UNII | |
CompTox Dashboard (EPA)
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| Properties | |
| Molar mass | |
| Appearance | blue solid |
| Density | 1.197 g/cm3 |
| Hazards | |
| GHS labelling:[1] | |
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| Warning | |
| H315, H319, H335 | |
| P261, P305+P351+P338 | |
| Flash point | 111.4 °C (232.5 °F; 384.5 K) |
| NIOSH (US health exposure limits):[3] | |
PEL (Permissible)
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TWA 1 mg/m3 (as Cu) |
REL (Recommended)
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TWA 1 mg/m3 (as Cu) |
IDLH (Immediate danger)
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TWA 100 mg/m3 (as Cu) |
| Related compounds | |
Other cations
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Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Copper benzoate is the chemical compound with the formula Cu2(C6H5CO2)4(H2O)2. These coordination complexes are derived from the cupric ion and the conjugate base of benzoic acid. Many derivatives are known with diverse ancillary ligands.[citation needed] It has found some niche use as a combination fuel and source of copper ion for blue light production in fireworks.[4]
Preparation
[edit]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:[citation needed]
- 4 K(C6H5CO2) + 2 CuSO4·5H2O → Cu2(C6H5CO2)4(H2O)2 + 2 K2SO4 + 8 H2O
Uses
[edit]It is sometimes used by hobbyists as a fuel and blue flame colorant in pyrotechnics, but it is not on the list of chemicals approved in consumer fireworks in the US.[5]
It is also used in two-part dental adhesives, in polyester resin compositions to increase thermal resistance and decrease gelation, and as a metal-based hydrogen sulfide scavenger in asphalt.[1]
Structure
[edit]4(aq)2.svg)
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,[6][page needed] 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.[7] A hydrated form is also known, wherein each Cu(II) centre is bound to four water ligands and a bidentate O,O-benzoate.[8]
Related compounds
[edit]References
[edit]- ^ a b c d "Copper Benzoate SDS" (PDF). JPharmaChem. Dr. J. Pharmachem Pvt. Ltd. Retrieved 12 July 2025.
- ^ a b Sigma-Aldrich Co., Benzoic acid, copper (II) salt dihydrate.
- ^ "NIOSH Pocket Guide to Chemical Hazards".
- ^ "Formulas For Firework Stars Using Copper Benzoate". Skylighter, Inc. Retrieved 2025-05-27.
- ^ "Approved and Prohibited Fireworks Chemicals" (PDF). www.phmsa.dot.gov. US Department of Transportation. Retrieved 12 July 2025.
- ^ Wells, A. F. (1984). Structural inorganic chemistry (5th ed.). Oxford [Oxfordshire] : New York: Clarendon Press ; Oxford University Press. ISBN 0-19-855370-6.
- ^ Kawata, T.; Uekusa, H.; Ohba, S.; Furukawa, T.; Tokii, T.; Muto, Y.; Kato, M. (1 June 1992). "Magneto-structural correlation in dimeric copper(II) benzoates". Acta Crystallographica Section B Structural Science. 48 (3): 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.