Chrome orange

Last updated
Chrome orange
Chromorange 2.jpg
Names
Other names
  • Basic chromium lead oxide
  • Chromium dilead pentaoxide
  • Chromium lead oxide
  • Dilead chromate oxide
  • Lead chromate oxide
  • Lead chromate(VI) oxide
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.038.476 OOjs UI icon edit-ltr-progressive.svg
EC Number
  • 242-339-9
PubChem CID
  • InChI=1S/Cr.5O.2Pb/q;;;;2*-1;;+2
    Key: BXVHGCHMBBNRBU-UHFFFAOYSA-N
  • [O-][Cr](=O)(=O)[O-].O=[Pb].[Pb+2]
Properties [1]
CrO5Pb2
Molar mass 546.4 g·mol−1
Appearancered solid
Density 6.63 g/cm3
Melting point 920 °C (1,690 °F; 1,190 K)
insoluble
Solubility soluble in acids, alkalis
Structure [2]
monoclinic
c2/m
a = 14.018 Å, b = 5.683 Å, c = 7.143 Å
α = 90°, β = 115.23°, γ = 90°
514.8 Å3
4 units per cell
Thermochemistry [3]
-1161.3 kJ/mol
Hazards
GHS labelling: [1]
GHS-pictogram-exclam.svg GHS-pictogram-silhouette.svg GHS-pictogram-pollu.svg
Danger
H302, H332, H360, H373, H410
P203, P260, P264, P270, P271, P273, P280, P301+P317, P304+P340, P317, P318, P319, P330, P391, P405, P501
0.0002 mg/m3, 0.0005 mg/m3 (STEL)
NIOSH (US health exposure limits): [1]
IDLH (Immediate danger)
100.0 mg/m3
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Chrome orange is a mixed oxide with the chemical formula Pb2CrO5. It has found use as a pigment.

Contents

Properties

Visible light activity up to 550 nanometers has been recorded. [4]

Synthesis

Pb2CrO5 can be made by treating a lead(II) salt with an alkaline solution of a chromate or by treating chrome yellow (PbCrO4) with strongly basic solution. [5]

It can also be synthesized using a gas-liquid precipitation process. [6] Changing the pH controls whether PbCrO4 or Pb2CrO5 is created. [6]

Nanomaterial

Orthorhombic nanocrystals can be selectively synthesized by a room temperature solution reaction. [7]

Using a microwave-assisted ionic liquid (MAIL) method, bundle and rod-like nanocrystals of Pb2CrO5 are formed. [8] In basic solution, single-crystalline Pb2CrO5 could be formed by heating lead acetate and potassium dichromate with microwave radiation for only 10 minutes at 90 °C. [8] The MAIL process is simple, fast, and does not employ surfactants. [8] The presence of hydroxide changes the phase that is formed. Using NaOH, monoclinic Pb2CrO5 is formed. [8] The bundle and rod-shaped structures are sensitive to electron beam irradiation, which will turn them into many small particles. [8]

Pigment

In a catalog published c. 1835, Winsor and Newton paint company identify ten synthetic pathways for producing chrome orange, also called deep yellow. [9] Chrome orange is made of PbCrO4 mixed with basic lead chromate (Pb2CrO5). [9] It has been described as a "yellowish red or sometimes a beautiful deep red" in alkaline conditions. [9] A deep yellow can be created using PbCrO4 and lead sulfate. [9] There are ten synthetic methods for preparing deep chrome yellow (that made with Pb2CrO5), which require a chromate source, a basic lead source, additives, and a sulfate source. [9] Controlling the pH was Winsor and Newton's method for creating pigments from the pale yellow to the deep chrome orange. [9] The resulting product has a high stability to light, which is always coveted by artists and collectors. [9]

Use as a pigment

Chrome orange was used extensively in Frederic Leighton's Flaming June (1895; Museo de Arte de Ponce). Flaming June, by Frederic Lord Leighton (1830-1896).jpg
Chrome orange was used extensively in Frederic Leighton's Flaming June (1895; Museo de Arte de Ponce).
Chrome Orange
 
Information icon4.svg    Color coordinates
Hex triplet #E73501
sRGB B (r, g, b)(231, 53, 1)
HSV (h, s, v)(14°, 100%, 91%)
CIELChuv (L, C, h)(51, 147, 16°)
SourceColourLex [11]
B: Normalized to [0–255] (byte)

Chrome orange can range in color from light to deep orange and is no longer in production as a pigment. [12] It has also been known as Derby red, Persian red, and Victoria red. [12] It was first recorded as a pigment in 1809 and was perfect for some impressionist painters in the nineteenth century. The yellow-orange pigment of the boat in Renoir's 1879 painting, The Seine at Asnières (The Skiff) at the National Gallery, London. [12] Chrome orange was used extensively in Frederic Leighton's Flaming June (1895; Museo de Arte de Ponce). [10]

History

The natural mineral crocoite was discovered in 1797 by Louis Vauquelin and chrome orange was synthesized as a pigment for the first time in 1809. [12] Pb2CrO5 is found in mineral form as phoenicochroite, which is a monoclinic, red, translucent mineral found in various places across the world, including Russia, the US, and Chile. [13]

See also

References

  1. 1 2 3 PubChem. "Lead chromate oxide". pubchem.ncbi.nlm.nih.gov. Retrieved 2026-02-11.
  2. ↑ Morita, Shinichi; Toda, Kohji (1984-04-01). "Determination of the crystal structure of Pb2CrO5". Journal of Applied Physics. 55 (7): 2733–2737. doi:10.1063/1.333271. ISSN   0021-8979.
  3. ↑ Sahu, Sulata Kumari; Ganesan, Rajesh; Gnanasekaran, T. (2010-01-01). "Standard molar Gibbs free energy of formation of Pb5CrO8(s), Pb2CrO5(s), and PbCrO4(s)" . The Journal of Chemical Thermodynamics. 42 (1): 1–7. doi:10.1016/j.jct.2009.06.026. ISSN   0021-9614. S2CID   55549520.
  4. ↑ Lee, Heung Chan; Cho, Sung Ki; Park, Hyun S.; Nam, Ki Min; Bard, Allen J. (2017-08-24). "Visible Light Photoelectrochemical Properties of PbCrO 4, Pb 2 CrO 5, and Pb 5 CrO 8" . The Journal of Physical Chemistry C. 121 (33): 17561–17568. doi:10.1021/acs.jpcc.7b03230. ISSN   1932-7447.
  5. ↑ Völz, Hans G.; et al. (2006). "Pigments, Inorganic". Ullmann's Encyclopedia of Industrial Chemistry. Wiley-VCH. doi:10.1002/14356007.a20_243.pub2. ISBN   3527306730..
  6. 1 2 Gu, LiNa; Meng, GuangYao (2007-09-05). "Synthesis and characterization of two PbO-chromium oxides" . Powder Technology. 178 (1): 1–4. doi:10.1016/j.powtec.2007.01.017. ISSN   0032-5910.
  7. ↑ Ma, Ming-Guo; Zhu, Ying-Jie; Li, Shu-Hong (2009-02-04). "A simple route to the synthesis of BaCrO4 microstructures at room temperature" . Materials Research Bulletin. 44 (2): 288–293. doi:10.1016/j.materresbull.2008.06.003. ISSN   0025-5408.
  8. 1 2 3 4 5 Wang, Wei-Wei; Zhu, Ying-Jie (2005-03-01). "Synthesis of PbCrO 4 and Pb 2 CrO 5 Rods via a Microwave-Assisted Ionic Liquid Method" . Crystal Growth & Design. 5 (2): 505–507. doi:10.1021/cg0497546. ISSN   1528-7483.
  9. 1 2 3 4 5 6 7 Otero, Vanessa; Pinto, Joana V.; Carlyle, Leslie; Vilarigues, Márcia; Cotte, Marine; João Melo, Maria (2017). "Nineteenth Century Chrome Yellow and Chrome Deep from Winsor & Newton". Studies in Conservation. 62 (3): 123–149. doi:10.1080/00393630.2015.1131478. S2CID   138176187.
  10. 1 2 Color in the Making. London: Black Dog Publishing. 2013. p. 104. ISBN   9781907317958.
  11. ↑ "Chrome orange – ColourLex". ColourLex. Retrieved 22 December 2022.
  12. 1 2 3 4 "Pigments through the Ages – Overview – Chrome orange". webexhibits.org. Retrieved 2022-05-11.
  13. ↑ "Phoenicochroite". mindat.org. Retrieved 2022-05-11.

Further reading

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