Urea phosphate

Urea phosphate
Names
	IUPAC name phosphoric acid;urea
Identifiers
CAS Number	4401-74-5; 4861-19-2;
3D model (JSmol)	Interactive image;
ChemSpider	19748;
ECHA InfoCard	100.023.149
EC Number	225-464-3;
PubChem CID	20994;
UNII	TJR09610O7;
CompTox Dashboard (EPA)	DTXSID3063627 ;
	InChI InChI=1S/CH4N2O.H3O4P/c2-1(3)4;1-5(2,3)4/h(H4,2,3,4);(H3,1,2,3,4) Key: DZHMRSPXDUUJER-UHFFFAOYSA-N;
	SMILES C(=O)(N)N.OP(=O)(O)O;
Properties
Chemical formula	CH7N2O5P
Molar mass	158.050 g·mol−1
Hazards
	GHS labelling:
Pictograms
Signal word	Danger
Hazard statements	H314
Precautionary statements	P260, P264, P280, P301+P330+P331, P303+P361+P353, P304+P340, P305+P351+P338, P310, P321, P363, P405, P501
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Urea phosphate is a 1:1 combination of urea and phosphoric acid that is used as a fertilizer. It has an NPK formula of 17-44-0,^[1] and is soluble in water, producing a strongly acidic solution.

Urea phosphate is available in fertilizer vendor bags that carry a UP signet on the packaging. It is sometimes added to blends which contain calcium nitrate, magnesium nitrate and potassium nitrate to produce water-soluble formulas such as 15-5-15 and 13-2-20. The acidity of urea phosphate allows Ca, Mg and P to co-exist in solution. Under less acidic conditions, there would be precipitation of Ca–Mg phosphates. Urea phosphate is often used in drip irrigation to clean pipe systems.^[2]^[3]

The phosphoric acid and urea molecules in the urea phosphate crystal structure form a complex hydrogen-bonding network,^[4] with the hydrogen atoms bonding more strongly to urea molecules.^[5] It freely dissociates when dissolved in water.

Urea phosphate is produced as a non-ionic adduct of urea and phosphoric acid,^[6] with the typical 17-44-0 grade of fertilizer produced using wet process phosphoric acid at concentrations that vary from 54%^[1] to 90%:^[7]

H₃PO₄(aq) + (NH₂)₂CO(s) → (NH₂)₂CO · H₃PO₄(s)

References

^ ^a ^b Stinson, John M. (1977). Purified Liquid Fertilizers from Wet-process Acid Via Solid Urea Phosphate. National Fertilizer Development Center, Tennessee Valley Authority. p. 3.
^ Ramachandrula, Venkata Ramamohan; Kasa, Ramamohan Reddy (2022-10-01). "Prevention and treatment of drip emitter clogging: a review of various innovative methods". Water Practice and Technology. 17 (10): 2059–2070. doi:10.2166/wpt.2022.115. ISSN 1751-231X.
^ Stroehlein, J. L.; Rubeiz, I. G.; Oebker, N. F. (April 1986). "Urea Phosphate Applied by Subsurface Drip Irrigation Increases Availability of Soil Nitrogen and Phosphorus". Vegetable Report. hdl:10150/214135.
^ Sundera-Rao, R. V. G.; Turley, J. W.; Pepinsky, R. (1957). "The crystal structure of urea phosphate". Acta Crystallogr. 10 (6): 435–436. Bibcode:1957AcCry..10..435S. doi:10.1107/S0365110X57001425.
^ Rodrigues, Bernardo Lages; Tellgren, Roland; Fernandes, Nelson G. (2001-06-01). "Experimental electron density of urea–phosphoric acid (1/1) at 100 K". Acta Crystallographica Section B Structural Science. 57 (3): 353–358. doi:10.1107/S0108768101004359. ISSN 0108-7681.
^ Lagier, Claudia M.; Zuriaga, Mariano; Monti, Gustavo; Olivieri, Alejandro C. (September 1996). "Urea-phosphoric acid complex studied by variable temperature 31P NMR spectroscopy and semiempirical calculations". Journal of Physics and Chemistry of Solids. 57 (9): 1183–1190. Bibcode:1996JPCS...57.1183L. doi:10.1016/0022-3697(95)00294-4.
^ Jančaitienė, Kristina; Medekšaitė, Agnė; Šlinkšienė, Rasa (2023-11-14). "Influence of the Process Parameters on the Synthesis of Urea Phosphate and the Properties of the Obtained Product". Crystals. 13 (11): 1584. doi:10.3390/cryst13111584. ISSN 2073-4352.

[:0-1] Stinson, John M. (1977). Purified Liquid Fertilizers from Wet-process Acid Via Solid Urea Phosphate. National Fertilizer Development Center, Tennessee Valley Authority. p. 3.

[2] Ramachandrula, Venkata Ramamohan; Kasa, Ramamohan Reddy (2022-10-01). "Prevention and treatment of drip emitter clogging: a review of various innovative methods". Water Practice and Technology. 17 (10): 2059–2070. doi:10.2166/wpt.2022.115. ISSN 1751-231X.

[3] Stroehlein, J. L.; Rubeiz, I. G.; Oebker, N. F. (April 1986). "Urea Phosphate Applied by Subsurface Drip Irrigation Increases Availability of Soil Nitrogen and Phosphorus". Vegetable Report. hdl:10150/214135.

[4] Sundera-Rao, R. V. G.; Turley, J. W.; Pepinsky, R. (1957). "The crystal structure of urea phosphate". Acta Crystallogr. 10 (6): 435–436. Bibcode:1957AcCry..10..435S. doi:10.1107/S0365110X57001425.

[5] Rodrigues, Bernardo Lages; Tellgren, Roland; Fernandes, Nelson G. (2001-06-01). "Experimental electron density of urea–phosphoric acid (1/1) at 100 K". Acta Crystallographica Section B Structural Science. 57 (3): 353–358. doi:10.1107/S0108768101004359. ISSN 0108-7681.

[6] Lagier, Claudia M.; Zuriaga, Mariano; Monti, Gustavo; Olivieri, Alejandro C. (September 1996). "Urea-phosphoric acid complex studied by variable temperature 31P NMR spectroscopy and semiempirical calculations". Journal of Physics and Chemistry of Solids. 57 (9): 1183–1190. Bibcode:1996JPCS...57.1183L. doi:10.1016/0022-3697(95)00294-4.

[7] Jančaitienė, Kristina; Medekšaitė, Agnė; Šlinkšienė, Rasa (2023-11-14). "Influence of the Process Parameters on the Synthesis of Urea Phosphate and the Properties of the Obtained Product". Crystals. 13 (11): 1584. doi:10.3390/cryst13111584. ISSN 2073-4352.

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