Violuric acid

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Violuric acid
Violursaure.svg
Violuric acid monohydrate.jpg
Names
IUPAC name
6-Hydroxy-5-nitroso-1H-pyrimidine-2,4-dione
Other names
2,4,5,6(1H,3H)-Pyrimidinetetrone 5-oxime
5-Hydroxyiminobarbituric acid
5-Isonitrosobarbituric acid
Alloxan 5-oxime
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.001.584 OOjs UI icon edit-ltr-progressive.svg
EC Number
  • 201-741-4
PubChem CID
UNII
  • InChI=1S/C4H3N3O4/c8-2-1(7-11)3(9)6-4(10)5-2/h(H3,5,6,8,9,10)
    Key: HRRVLSKRYVIEPR-UHFFFAOYSA-N
  • C1(=C(NC(=O)NC1=O)O)N=O
Properties
C4H3N3O4 (anhydrous)
C4H3N3O4·H2O (monohydrate)
Molar mass 157.08 g/mol (anhydrous)
175.10 g/mol (monohydrate)
AppearanceOff-white yellow or yellow cream solid
Odor Odorless
Melting point 247 °C (477 °F; 520 K) (decomposes)
Boiling point Decomposes
0.704 g/100 mL (20 °C) [1]
Solubility Soluble in alcohols
Vapor pressure ~0 mmHg
Acidity (pKa)4.7
Hazards
Occupational safety and health (OHS/OSH):
Main hazards
Irritant
GHS labelling:
GHS-pictogram-exclam.svg
Warning
H315, H319, H335
P261, P305+P351+P338
Related compounds
Related compounds
Barbituric acid
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Violuric acid is an organic compound with the formula HON=C(CONH)2CO. It crystallizes as white or off-white monohydrate. The compound has attracted attention because its salts are deeply colored. [2]

Contents

Reactions

It readily deprotonated to give salts of the anion [ON=C(CONH)2CO], which are often deeply colored. [3] [4]

Preparation

It was prepared by Adolf Baeyer by reaction of barbituric acid with nitrous acid. [5] It can also be produced by condensation of alloxan with hydroxylamine. [4] [6] as typical for forming the oxime of other carbonyl compounds.

Analytical reagents

Structure of the ferrous complex with three violurate ligands. FeV3anion.svg
Structure of the ferrous complex with three violurate ligands.

Violuric acid and many of its derivatives, such as thiovioluric acid, 1,3-dimethylvioluric acid, and diphenylthiovioluric acid, have historically been used as analytical reagents for spectrophotometric determination and titration of various metals and metal-ions. [8] It was also used as a novel staining/spraying agent for inorganic paper chromatography to identify and separate metals based on color. [9] Most derivatives of violuric acid will also typically form brightly colored salts with most metals and nitrogen bases. [10]

Because of the characteristic and diverse colors that violuric acid forms with alkali metals, it has been used photometrically to determine the amount of sodium in blood serum. [11]

Related Research Articles

<span class="mw-page-title-main">Perchloric acid</span> Chemical compound

Perchloric acid is a mineral acid with the formula HClO4. Usually found as an aqueous solution, this colorless compound is a stronger acid than sulfuric acid, nitric acid and hydrochloric acid. It is a powerful oxidizer when hot, but aqueous solutions up to approximately 70% by weight at room temperature are generally safe, only showing strong acid features and no oxidizing properties. Perchloric acid is useful for preparing perchlorate salts, especially ammonium perchlorate, an important rocket fuel component. Perchloric acid is dangerously corrosive and readily forms potentially explosive mixtures.

<span class="mw-page-title-main">Sodium carbonate</span> Chemical compound

Sodium carbonate is the inorganic compound with the formula Na2CO3 and its various hydrates. All forms are white, odourless, water-soluble salts that yield alkaline solutions in water. Historically, it was extracted from the ashes of plants grown in sodium-rich soils, and because the ashes of these sodium-rich plants were noticeably different from ashes of wood, sodium carbonate became known as "soda ash". It is produced in large quantities from sodium chloride and limestone by the Solvay process, as well as by carbonating sodium hydroxide which is made using the Chlor-alkali process.

<span class="mw-page-title-main">Barium hydroxide</span> Chemical compound

Barium hydroxide is a chemical compound with the chemical formula Ba(OH)2. The monohydrate (x = 1), known as baryta or baryta-water, is one of the principal compounds of barium. This white granular monohydrate is the usual commercial form.

<span class="mw-page-title-main">Sulfamic acid</span> Chemical compound

Sulfamic acid, also known as amidosulfonic acid, amidosulfuric acid, aminosulfonic acid, sulphamic acid and sulfamidic acid, is a molecular compound with the formula H3NSO3. This colourless, water-soluble compound finds many applications. Sulfamic acid melts at 205 °C before decomposing at higher temperatures to water, sulfur trioxide, sulfur dioxide and nitrogen.

<span class="mw-page-title-main">Murexide</span> Chemical compound

Murexide (NH4C8H4N5O6, or C8H5N5O6·NH3), also called ammonium purpurate or MX, is the ammonium salt of purpuric acid. It is a purple solid that is soluble in water. The compound was once used as an indicator reagent. Aqueous solutions are yellow at low pH, reddish-purple in weakly acidic solutions, and blue-purple in alkaline solutions.

<span class="mw-page-title-main">Iron(III) nitrate</span> Chemical compound

Iron(III) nitrate, or ferric nitrate, is the name used for a series of inorganic compounds with the formula Fe(NO3)3.(H2O)n. Most common is the nonahydrate Fe(NO3)3.(H2O)9. The hydrates are all pale colored, water-soluble paramagnetic salts.

<span class="mw-page-title-main">Manganese(II) sulfate</span> Chemical compound

Manganese(II) sulfate usually refers to the inorganic compound with the formula MnSO4·H2O. This pale pink deliquescent solid is a commercially significant manganese(II) salt. Approximately 260,000 tonnes of manganese(II) sulfate were produced worldwide in 2005. It is the precursor to manganese metal and many other chemical compounds. Manganese-deficient soil is remediated with this salt.

<span class="mw-page-title-main">Ammonium tetrathiomolybdate</span> Chemical compound

Ammonium tetrathiomolybdate is the chemical compound with the formula (NH4)2MoS4. This bright red ammonium salt is an important reagent in the chemistry of molybdenum and has been used as a building block in bioinorganic chemistry. The thiometallate (see metallate) anion has the distinctive property of undergoing oxidation at the sulfur centers concomitant with reduction of the metal from Mo(VI) to Mo(IV).

<span class="mw-page-title-main">Hexafluorophosphate</span> Anion with the chemical formula PF6–

Hexafluorophosphate is an anion with chemical formula of [PF6]. It is an octahedral species that imparts no color to its salts. [PF6] is isoelectronic with sulfur hexafluoride, SF6, and the hexafluorosilicate dianion, [SiF6]2−, and hexafluoroantimonate [SbF6]. In this anion, phosphorus has a valence of 5. Being poorly nucleophilic, hexafluorophosphate is classified as a non-coordinating anion.

<span class="mw-page-title-main">Fluoroboric acid</span> Chemical compound

Fluoroboric acid or tetrafluoroboric acid is an inorganic compound with the simplified chemical formula H+[BF4]. Solvent-free tetrafluoroboric acid has not been reported. The term "fluoroboric acid" usually refers to a range of compounds including hydronium tetrafluoroborate, which are available as solutions. The ethyl ether solvate is also commercially available, where the fluoroboric acid can be represented by the formula [H( 2O)n]+[BF4], where n is 2.

<span class="mw-page-title-main">Tetraphenylphosphonium chloride</span> Chemical compound

Tetraphenylphosphonium chloride is the chemical compound with the formula [(C6H5)4P]Cl, abbreviated Ph4PCl or PPh4Cl or [PPh4]Cl, where Ph stands for phenyl. Tetraphenylphosphonium and especially tetraphenylarsonium salts were formerly of interest in gravimetric analysis of perchlorate and related oxyanions. This colourless salt is used to generate lipophilic salts from inorganic and organometallic anions. Thus, [Ph4P]+ is useful as a phase-transfer catalyst, again because it allows inorganic anions to dissolve in organic solvents.

<span class="mw-page-title-main">Cobalt(II) sulfate</span> Inorganic compound

Cobalt(II) sulfate is any of the inorganic compounds with the formula CoSO4(H2O)x. Usually cobalt sulfate refers to the hexa- or heptahydrates CoSO4.6H2O or CoSO4.7H2O, respectively. The heptahydrate is a red solid that is soluble in water and methanol. Since cobalt(II) has an odd number of electrons, its salts are paramagnetic.

The perrhenate ion is the anion with the formula ReO
4
, or a compound containing this ion. The perrhenate anion is tetrahedral, being similar in size and shape to perchlorate and the valence isoelectronic permanganate. The perrhenate anion is stable over a broad pH range and can be precipitated from solutions with the use of organic cations. At normal pH, perrhenate exists as metaperrhenate, but at high pH mesoperrhenate forms. Perrhenate, like its conjugate acid perrhenic acid, features rhenium in the oxidation state of +7 with a d0 configuration. Solid perrhenate salts takes on the color of the cation.

<span class="mw-page-title-main">Croconic acid</span> Chemical compound

Croconic acid is a chemical compound with formula C5H2O5 or (C=O)3(COH)2. It has a cyclopentene backbone with two hydroxyl groups adjacent to the double bond and three ketone groups on the remaining carbon atoms. It is sensitive to light, soluble in water and ethanol and forms yellow crystals that decompose at 212 °C.

<span class="mw-page-title-main">Croconate violet</span>

Croconate violet or 1,3-bis(dicyanomethylene)croconate is a divalent anion with chemical formula C
11
N
4
O2−
3
or ((N≡C−)2C=)2(C5O3)2−. It is one of the pseudo-oxocarbon anions, as it can be described as a derivative of the croconate oxocarbon anion C
5
O2−
5
through the replacement of two oxygen atoms by dicyanomethylene groups =C(−C≡N)2. Its systematic name is 3,5-bis(dicyanomethylene)-1,2,4-trionate. The term croconate violet as a dye name specifically refers to the dipotassium salt K
2
C
11
N
4
O
3
.

<span class="mw-page-title-main">Ammonium carbamate</span> Chemical compound

Ammonium carbamate is a chemical compound with the formula [NH4][H2NCO2] consisting of ammonium cation NH+4 and carbamate anion NH2COO. It is a white solid that is extremely soluble in water, less so in alcohol. Ammonium carbamate can be formed by the reaction of ammonia NH3 with carbon dioxide CO2, and will slowly decompose to those gases at ordinary temperatures and pressures. It is an intermediate in the industrial synthesis of urea (NH2)2CO, an important fertilizer.

<span class="mw-page-title-main">Monofluorophosphate</span> Chemical compound

Monofluorophosphate is an anion with the formula PO3F2−, which is a phosphate group with one oxygen atom substituted with a fluoride atom. The charge of the ion is −2. The ion resembles sulfate in size, shape and charge, and can thus form compounds with the same structure as sulfates. These include Tutton's salts and langbeinites. The most well-known compound of monofluorophosphate is sodium monofluorophosphate, commonly used in toothpaste.

<span class="mw-page-title-main">Difluorophosphate</span> Chemical compound

Difluorophosphate or difluorodioxophosphate or phosphorodifluoridate is an anion with formula PO2F−2. It has a single negative charge and resembles perchlorate and monofluorosulfonate in shape and compounds. These ions are isoelectronic, along with tetrafluoroaluminate, phosphate, orthosilicate, and sulfate. It forms a series of compounds. The ion is toxic to mammals as it causes blockage to iodine uptake in the thyroid. However it is degraded in the body over several hours.

<span class="mw-page-title-main">Caesium oxalate</span> Chemical compound

Caesium oxalate, or dicesium oxalate, or cesium oxalate is a chemical compound with the chemical formula Cs2C2O4. It is a caesium salt of oxalic acid. It consists of caesium cations Cs+ and oxalate anions C2O2−4.

<span class="mw-page-title-main">Yttrium oxalate</span> Chemical compound

Yttrium oxalate is an inorganic compound, a salt of yttrium and oxalic acid with the chemical formula Y2(C2O4)3. The compound does not dissolve in water and forms crystalline hydrates—colorless crystals.

References

  1. "Registration Dossier - ECHA".
  2. Guille, Kathy; Harrington, Ross W.; Clegg, William (2007). "Violuric acid monohydrate: A second polymorph with more extensive hydrogen bonding". Acta Crystallographica Section C Crystal Structure Communications. 63 (6): o327–o329. Bibcode:2007AcCrC..63O.327G. doi:10.1107/S010827010701743X. PMID   17551193.
  3. Nichol, Gary S.; Clegg, William (2007). "Ammonium Violurate: A Compact Structure with Extensive Hydrogen Bonding in Three Dimensions". Acta Crystallographica Section C Crystal Structure Communications. 63 (10): o609–o612. Bibcode:2007AcCrC..63O.609N. doi:10.1107/S0108270107044241. PMID   17917236.
  4. 1 2 Liebing, Phil; Stein, Franziska; Hilfert, Liane; Lorenz, Volker; Oliynyk, Karyna; Edelmann, Frank T. (2019). "Synthesis and Structural Investigation of Brightly Colored Organoammonium Violurates". Zeitschrift für Anorganische und Allgemeine Chemie. 645: 36–43. doi:10.1002/zaac.201800439. S2CID   104376844.
  5. Baeyer, Adolf (1863). "Untersuchungen über die Harnsäuregruppe". Annalen der Chemie und Pharmacie. 127 (2): 199–236. doi:10.1002/jlac.18631270214.
  6. Guinchard, J. (1899). "Ueber die farbigen Salze aus Violursäure und anderen ringförmigen Oximidoketonen". Berichte der Deutschen Chemischen Gesellschaft. 32 (2): 1723–1741. doi:10.1002/cber.18990320260.
  7. Raston, Colin L.; White, Allan H. (1976). "Salts of the Tris(violurato)ferrate(II) Ion: Crystal Structure of Ammonium Tris(violurato)ferrate(II) Hydrate". Journal of the Chemical Society, Dalton Transactions (19): 1915. doi:10.1039/DT9760001915.
  8. Taylor, M. E.; Robinson, R. J. (1962-04-01). "The Use of 1,3-Dimethylvioluric Acid in Spectrophotometric Titrations of Alkali and Alkaline Earth Salts". Analytical Chemistry. 34 (4): 533–536. doi:10.1021/ac60184a026. ISSN   0003-2700.
  9. Singh, A. K.; Katyal, Mohan; Singh, R. P. (1976). "Violuric Acids as Analytical Reagents". Current Science. 45 (11): 405–408. ISSN   0011-3891. JSTOR   24079761.
  10. Lorenz, Volker; Liebing, Phil; Engelhardt, Felix; Stein, Franziska; Kühling, Marcel; Schröder, Lea; Edelmann, Frank T. (2019-01-02). "Review: the multicolored coordination chemistry of violurate anions". Journal of Coordination Chemistry. 72 (1): 1–34. doi:10.1080/00958972.2018.1560431. ISSN   0095-8972. S2CID   104419386.
  11. Muraca, R.F. (1955). "Photometric determination of sodium in blood serum with violuric acid" . Chemist Analyst. 44: 38–42 via CAB Direct.