Copper citrate

Copper(II) citrate

Anhydrous copper(II) citrate
Names
IUPAC name copper(II) 2-oxidopropane-1,2,3-tricarboxylate
Other names cupric citrate; dicopper citrate
Identifiers
CAS Number	866-82-0 [1] hemipentahydrate: 6020-30-0
3D model (JSmol)	Interactive image hemipentahydrate: Interactive image
ChemSpider	21171752 hemipentahydrate: 32700143
ECHA InfoCard	100.169.194
EC Number	212-752-9
PubChem CID	14454876 hemipentahydrate: 71586843
UNII	F70D117TTU hemipentahydrate: L40S1PLZ5W
CompTox Dashboard (EPA)	DTXSID00881033 DTXSID3047500, DTXSID00881033
InChI InChI=1S/C6H7O7.2Cu/c7-3(8)1-6(13,5(11)12)2-4(9)10;;/h1-2H2,(H,7,8)(H,9,10)(H,11,12);;/q-1;2*+2/p-3 Key: FWBOFUGDKHMVPI-UHFFFAOYSA-K hemipentahydrate:InChI=1S/2C6H7O7.4Cu.5H2O/c2*7-3(8)1-6(13,5(11)12)2-4(9)10;;;;;;;;;/h2*1-2H2,(H,7,8)(H,9,10)(H,11,12);;;;;5*1H2/q2*-1;4*+2;;;;;/p-6 Key: NBHBWRHMKGDJMS-UHFFFAOYSA-H
SMILES C(C(=O)[O-])C(CC(=O)[O-])(C(=O)[O-])[O-].[Cu+2].[Cu+2] hemipentahydrate:C(C(=O)[O-])C(CC(=O)[O-])(C(=O)[O-])[O-].C(C(=O)[O-])C(CC(=O)[O-])(C(=O)[O-])[O-].O.O.O.O.O.[Cu+2].[Cu+2].[Cu+2].[Cu+2]
Properties
Chemical formula	C6H4Cu2O7 (anhydrous); C6H4Cu2O7·2.5H2O (hemipentahydrate) [1]
Molar mass	315.18 g·mol-1 (anhydrous); 360.22 g·mol-1 (2.5-hydrate) [2]
Appearance	blue-green solid [2]
Density	1.667 g·cm-3 [2]
Solubility in water	slightly soluble in water; more soluble in dilute acids and in aqueous ammonia [3]
Hazards
GHS labelling:
Pictograms
Signal word	Warning
Hazard statements	H302, H410
Precautionary statements	P264, P270, P273, P301+P317, P330, P391, P501
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Copper(II) citrate is the copper(II) salt of citric acid that occurs in several hydration states. Commercial material is commonly a blue-green solid and is used as a source of copper in industrial, agricultural and some supplement applications. ^{[1] [2]}

Preparation

Copper(II) citrate can be prepared by reacting a soluble copper(II) salt such as copper(II) sulfate with trisodium citrate or tripotassium citrate; different hydrate stoichiometries may be isolated depending on conditions. ^[4]

Properties

The anhydrous powder is blue while the hydrate is a light green. ^[2]

Uses

Copper(II) citrate is used as a copper source in some agricultural micronutrient formulations and in proprietary supplement formulations. It is also used as a reagent and copper source in industrial and research contexts. ^{[5] [6]}

References

1. "Cupric citrate". PubChem. Retrieved 2025-11-17.
2. "Copper(II) Citrate 2.5-Water product data". FUJIFILM Wako. Retrieved 2025-11-17.
3. "Copper citrate - supplier data and solubility notes". Lohmann Minerals. Retrieved 2025-11-17.
4. "Cupric citrate — product information". Sigma-Aldrich / Merck. Retrieved 2025-11-17.
5. "Copper fungicides for organic and conventional disease management in vegetables". Cornell University. Retrieved 2025-11-17.
6. "Copper supplements: product example". Pure Encapsulations (product page). Retrieved 2025-11-17.