Rosocyanine

Last updated
Rosocyanine
Rosocyanine.svg
Names
IUPAC name
2-methoxy-4-[(E)-2-[2,4,10-tris[(E)-2-(4-hydroxy-3-methoxyphenyl)ethenyl]-1,5,7,11-tetraoxa-6-boroniaspiro[5.5]undecan-8-yl]ethenyl]phenol;chloride
Other names
Rosocyanine
Identifiers
3D model (JSmol)
ChemSpider
PubChem CID
  • InChI=1S/C42H44BO12.ClH/c1-48-39-21-27(9-17-35(39)44)5-13-31-25-32(14-6-28-10-18-36(45)40(22-28)49-2)53-43(52-31)54-33(15-7-29-11-19-37(46)41(23-29)50-3)26-34(55-43)16-8-30-12-20-38(47)42(24-30)51-4;/h5-24,31-34,44-47H,25-26H2,1-4H3;1H/q+1;/p-1/b13-5+,14-6+,15-7+,16-8+; Yes check.svgY
    Key: XZWTYNUGOWPDCM-JWMINOHISA-M Yes check.svgY
  • InChI=1S/C42H44BO12.ClH/c1-48-39-21-27(9-17-35(39)44)5-13-31-25-32(14-6-28-10-18-36(45)40(22-28)49-2)53-43(52-31)54-33(15-7-29-11-19-37(46)41(23-29)50-3)26-34(55-43)16-8-30-12-20-38(47)42(24-30)51-4;/h5-24,31-34,44-47H,25-26H2,1-4H3;1H/q+1;/p-1/b13-5+,14-6+,15-7+,16-8+;
  • Key: XZWTYNUGOWPDCM-JWMINOHISA-M
  • [Cl-].Oc1ccc(cc1OC)/C=C/C5CC(O[B@+]3(OC(CC(/C=C/c2ccc(O)c(OC)c2)O3)/C=C/c4ccc(O)c(OC)c4)O5)/C=C/c6ccc(O)c(OC)c6
Properties
[B(C21H19O6)2]Cl (as chloride)
Molar mass 781.013 g/mol
Appearancedark-green colored solid
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Yes check.svgY  verify  (what is  Yes check.svgYX mark.svgN ?)

Rosocyanine and rubrocurcumin are two red colored materials, which are formed by the reaction between curcumin and borates.

Contents

Application

The color reaction between borates and curcumin is used for the spectrophotometric determination and quantification of boron present in food or materials. Curcumin is a yellow coloring natural pigment found in the root stocks of some Curcuma species, especially Curcuma longa (turmeric), in concentrations up to 3%. In the so-called curcumin method for boron quantification it serves as reaction partner for boric acid. The reaction is very sensitive and so the smallest quantities of boron can be detected. The maximum absorbance at 540 nm for rosocyanine is used in this colorimetric method. The formation of rosocyanine depends on the reaction conditions. The reaction is carried out preferentially in acidic solutions containing hydrochloric or sulfuric acid. The color reaction also takes place under different conditions; however, in alkaline solution, gradual decomposition is observed. The reaction might be disturbed at higher pH values, interfering with other compounds.[ citation needed ]

Space filling model Rosocyanine-3D-vdW.png
Space filling model

Rosocyanine is formed as a 2:1 complex from curcumin and boric acid in acidic solutions. The boron complexes formed with rosocyanine are dioxaborines (here a 1,3,2-dioxaborine). Curcumin possesses a 1,3-diketone structure and can therefore be considered as a chelating agent. Unlike the simpler 1,3-diketonecontaining compound acetylacetone (which forms acetylacetonate complexes with metals), the entire skeleton of curcumin is in resonance with the 1,3-dicarbonyl section, making the backbone an extended conjugated system. Investigations of the structure have shown that the positive charge is distributed throughout the molecule. In rosocyanine, the two curcumin moieties are not coplanar but rather perpendicular relative to one another (as seen in the 3D model), as a result of the tetrahedral geometry of tetracoordinate boron. The same applies to rubrocurcumin.

In order to exclude the presence of other materials during the boron quantification using the curcumin method, a variant of the process was developed. In this process, 2,2-dimethyl-1,3-hexanediol or 2-ethyl-1,3-hexanediol are added, in addition to curcumin, to a neutral solution of the boron-containing solution. The complex formed between boron and the 1,3-hexanediol derivative is removed from the aqueous solution by extraction in an organic solvent. Acidification of the organic phase yields rubrocyanine, which can be detected by colorimetric methods. The reaction of curcumin with borates in presence of oxalic acid produces the coloring compound rubrocurcumin.

Characteristics

Rosocyanine is a dark green solid with a glossy, metallic shine that forms red colored solutions. It is almost insoluble in water and some organic solvents, very slightly soluble (up to 0.01%) in ethanol, and somewhat soluble (approximately 1%) in pyridine, sulfuric acid, and acetic acid. An alcoholic solution of rosocyanine temporarily turns deeply blue on treatment with alkali.

In rubrocurcumin one molecule of curcumin is replaced with oxalic acid. Rubrocurcumin produces a similar red colored solution. Rosocyanine is an ionic compound, while rubrocurcumin is a neutral complex.

See also

Related Research Articles

<span class="mw-page-title-main">Boron</span> Chemical element, symbol B and atomic number 5

Boron is a chemical element; it has symbol B and atomic number 5. In its crystalline form it is a brittle, dark, lustrous metalloid; in its amorphous form it is a brown powder. As the lightest element of the boron group it has three valence electrons for forming covalent bonds, resulting in many compounds such as boric acid, the mineral sodium borate, and the ultra-hard crystals of boron carbide and boron nitride.

<span class="mw-page-title-main">Boric acid</span> Weak acid with formula B(OH)₃

Boric acid, more specifically orthoboric acid, is a compound of boron, oxygen, and hydrogen with formula B(OH)3. It may also be called hydrogen orthoborate, trihydroxidoboron or boracic acid. It is usually encountered as colorless crystals or a white powder, that dissolves in water, and occurs in nature as the mineral sassolite. It is a weak acid that yields various borate anions and salts, and can react with alcohols to form borate esters.

A borate is any of a range of boron oxyanions, anions containing boron and oxygen, such as orthoborate BO3−3, metaborate BO−2, or tetraborate B4O2−7; or any salt of such anions, such as sodium metaborate, Na+[BO2] and borax (Na+)2[B4O7]2−. The name also refers to esters of such anions, such as trimethyl borate B(OCH3)3 but they are alkoxides.

<span class="mw-page-title-main">Borax</span> Boron compound, a salt of boric acid

Borax (also referred to as sodium borate, tincal and tincar ) is a salt (ionic compound), a hydrated or anhydrous borate of sodium, with the chemical formula Na2H20B4O17 (also written as Na2B4O7·10H2O).

<span class="mw-page-title-main">Dicarbonyl</span> Molecule containing two adjacent C=O groups

In organic chemistry, a dicarbonyl is a molecule containing two carbonyl groups. Although this term could refer to any organic compound containing two carbonyl groups, it is used more specifically to describe molecules in which both carbonyls are in close enough proximity that their reactivity is changed, such as 1,2-, 1,3-, and 1,4-dicarbonyls. Their properties often differ from those of monocarbonyls, and so they are usually considered functional groups of their own. These compounds can have symmetrical or unsymmetrical substituents on each carbonyl, and may also be functionally symmetrical or unsymmetrical.

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

Acetylacetone is an organic compound with the chemical formula CH3−C(=O)−CH2−C(=O)−CH3. It is classified as a 1,3-diketone. It exists in equilibrium with a tautomer CH3−C(=O)−CH=C(−OH)−CH3. The mixture is a colorless liquid. These tautomers interconvert so rapidly under most conditions that they are treated as a single compound in most applications. Acetylacetone is a building block for the synthesis of many coordination complexes as well as heterocyclic compounds.

<span class="mw-page-title-main">Organoboron chemistry</span> Study of compounds containing a boron-carbon bond

Organoboron chemistry or organoborane chemistry studies organoboron compounds, also called organoboranes. These chemical compounds combine boron and carbon; typically, they are organic derivatives of borane (BH3), as in the trialkyl boranes.

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

Triethyl borate is a colorless liquid with the formula B(OCH2CH3)3. It is an ester of boric acid and ethanol. It has few applications.

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

Trimethyl borate is the organoboron compound with the formula B(OCH3)3 and a metal alkoxide. It is a colourless liquid that burns with a green flame. It is an intermediate in the preparation of sodium borohydride and is a popular reagent in organic chemistry. It is a weak Lewis acid (AN = 23, Gutmann-Beckett method).

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

Rubrocurcumin is a red-colored dye that is formed by the reaction of curcumin and boric acid.

<span class="mw-page-title-main">Boronic acid</span> Organic compound of the form R–B(OH)2

A boronic acid is an organic compound related to boric acid in which one of the three hydroxyl groups is replaced by an alkyl or aryl group. As a compound containing a carbon–boron bond, members of this class thus belong to the larger class of organoboranes.

<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]. Unlike other strong acids like H2SO4 or HClO4, the pure tetrafluoroboric acid does not exist. The term "fluoroboric acid" refers to a range of chemical compounds, depending on the solvent. The H+ in the simplified formula of fluoroboric acid represents the solvated proton. The solvent can be any suitable Lewis base. For instance, if the solvent is water, fluoroboric acid can be represented by the formula [H3O]+[BF4], although more realistically, several water molecules solvate the proton: [H(H2O)n]+[BF4]. 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 most likely 2.

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

Disodium octaborate is a borate of sodium, a chemical compound of sodium, boron, and oxygen — a salt with elemental formula Na2B8O13 or (Na+)2[B8O13]2−, also written as Na2O·4B2O3. It is a colorless crystalline solid, soluble in water.

<span class="mw-page-title-main">Lithium tetrakis(pentafluorophenyl)borate</span> Chemical compound

Lithium tetrakis(pentafluorophenyl)borate is the lithium salt of the weakly coordinating anion (B(C6F5)4). Because of its weakly coordinating abilities, lithium tetrakis(pentafluorophenyl)borate makes it commercially valuable in the salt form in the catalyst composition for olefin polymerization reactions and in electrochemistry. It is a water-soluble compound. Its anion is closely related to the non-coordinating anion known as BARF. The tetrakis(pentafluorophenyl)borates have the advantage of operating on a one-to-one stoichiometric basis with Group IV transition metal polyolefin catalysts, unlike methylaluminoxane (MAO) which may be used in large excess.

<span class="mw-page-title-main">Borate esters</span> Organic compounds of the form B(OR)₃ or B₃O₃(OR)₃

In organic chemistry, borate esters are organoboron compounds which are conveniently prepared by the stoichiometric condensation reaction of boric acid with alcohols. There are two main classes of borate esters: orthoborates, B(OR)3 and metaborates, B3O3(OR)3. Metaborates contain 6-membered boroxine rings.

Boron phosphate is an inorganic compound with the chemical formula BPO4. The simplest way of producing it is the reaction of phosphoric acid and boric acid. It is a white infusible solid that evaporates above 1450 °C.

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

Cadmium tetrafluoroborate is an ionic, chemical compound with the formula Cd(BF4)2. It is a crystalline solid, which is colorless and odorless. Cadmium tetrafluoroborate is most frequently used in the industrial production of high-strength steels, its purpose being to prevent hydrogen absorption, a source of post-production cracking of the metal, in the treated steels. Another application of the chemistry of cadmium tetrafluoroborate is fine tuning of the size of cadmium telluride nanomaterials.

<span class="mw-page-title-main">Tris(2,2,2-trifluoroethyl) borate</span> Chemical compound

Tris(2,2,2-trifluoroethyl) borate, also commonly referred to as the Sheppard amidation reagent, is a chemical compound with the formula B(OCH2CF3)3. This borate ester reagent is used in organic synthesis.

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

In inorganic chemistry, an orthoborate is a polyatomic anion with formula [BO3]3− or a salt containing the anion; such as trisodium orthoborate (Na+)3[BO3]3−. It is one of several boron oxyanions, or borates.

Trisodium borate is a chemical compound of sodium, boron, and oxygen, with formula Na3BO3, or (Na+)3[BO3]3−. It is a sodium salt of the orthoboric acid B(OH)3.

References