Triphenylmethanol

Last updated
Triphenylmethanol
Triphenylmethanol.png
Triphenylmethanol crystals.jpg
Names
Preferred IUPAC name
Triphenylmethanol
Other names
Triphenylcarbinol
Tritanol
Identifiers
3D model (JSmol)
ChEMBL
ChemSpider
ECHA InfoCard 100.000.899 OOjs UI icon edit-ltr-progressive.svg
PubChem CID
UNII
  • InChI=1S/C19H16O/c20-19(16-10-4-1-5-11-16,17-12-6-2-7-13-17)18-14-8-3-9-15-18/h1-15,20H Yes check.svgY
    Key: LZTRCELOJRDYMQ-UHFFFAOYSA-N Yes check.svgY
  • InChI=1/C19H16O/c20-19(16-10-4-1-5-11-16,17-12-6-2-7-13-17)18-14-8-3-9-15-18/h1-15,20H
    Key: LZTRCELOJRDYMQ-UHFFFAOYAJ
  • OC(c1ccccc1)(c2ccccc2)c3ccccc3
Properties
C19H16O
Molar mass 260.33 g/mol
AppearanceWhite crystalline solid
Density 1.199 g/cm3
Melting point 160 to 163 °C (320 to 325 °F; 433 to 436 K)
Boiling point 360 to 380 °C (680 to 716 °F; 633 to 653 K)
-175.7·10−6 cm3/mol
Hazards
Safety data sheet (SDS) External MSDS
Related compounds
Related compounds
Triphenylmethane, Tricyclohexylmethanol
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 ?)

Triphenylmethanol (also known as triphenylcarbinol and TrOH) is an organic compound. It is a white crystalline solid that is insoluble in water and petroleum ether, but well soluble in ethanol, diethyl ether, and benzene. In strongly acidic solutions, it produces an intensely yellow color, due to the formation of a stable "trityl" carbocation. Many derivatives of triphenylmethanol are important dyes. [1]

Contents

History

After the German chemist August Kekulé and his Belgian student Antoine Paul Nicolas Franchimont (1844–1919) first synthesized triphenylmethane in 1872, [2] the Russian doctoral student Walerius Hemilian (1851–1914) first synthesized triphenylmethanol in 1874 by reacting triphenylmethyl bromide with water as well as by oxidizing triphenylmethane. [3]

Structure and properties

Triphenylmethanol features three phenyl (Ph) rings and an alcohol group bound to a central tetrahedral carbon atom. All three C–Ph bonds are typical of sp3-sp2 carbon-carbon bonds with lengths of approximately 1.47 Å, while the C–O bond length is approximately 1.42 Å. [4]

The presence of three adjacent phenyl groups confers special properties manifested in the reactivity of the alcohol. For example it reacts with acetyl chloride, not to give the ester, but triphenylmethyl chloride: [5]

Ph3COH + MeCOCl → Ph3CCl + MeCO2H

The three phenyl groups also offer steric protection. Reaction with hydrogen peroxide gives an unusually stable hydroperoxide, Ph3COOH. [6]

Acid-base properties

As a derivative of methanol, triphenylmethanol is expected to have a pKa in the range of 16-19. Typical of alcohols, resonance offers no stabilization of the conjugate base due to being bonded to a saturated carbon atom. Stabilization of the anion by solvation forces is largely ineffective due to the steric influence of the three phenyl groups.

The basicity of triphenylmethanol is enhanced due to the formation of a resonance-stabilized carbocation upon breaking of the C–O bond. After protonation of the oxygen under strongly acidic conditions, triphenylmethanol loses water to form the triphenylmethyl ("trityl") cation:

Ph3COH + H+ → Ph3C+ + H2O

The trityl cation is one of the easiest carbocations to isolate, although it quickly reacts with water.

Synthesis

The preparation of triphenylmethanol from methyl benzoate or benzophenone and phenylmagnesium bromide is a common laboratory experiment for illustrating the Grignard reaction. [7] An alternative starting material is diethyl carbonate. [8]

Synthesis of triphenylmethanol.png

Applications

Although not of major industrial importance, triphenylmethanol is a useful reagent in the research laboratory. Substituted derivatives of triphenylmethanol are intermediates in the production of the commercially useful triarylmethane dyes. [1]

Related Research Articles

<span class="mw-page-title-main">Ether</span> Organic compounds made of alkyl/aryl groups bound to oxygen (R–O–R)

In organic chemistry, ethers are a class of compounds that contain an ether group—an oxygen atom connected to two alkyl or aryl groups. They have the general formula R−O−R′, where R and R′ represent the alkyl or aryl groups. Ethers can again be classified into two varieties: if the alkyl or aryl groups are the same on both sides of the oxygen atom, then it is a simple or symmetrical ether, whereas if they are different, the ethers are called mixed or unsymmetrical ethers. A typical example of the first group is the solvent and anaesthetic diethyl ether, commonly referred to simply as "ether". Ethers are common in organic chemistry and even more prevalent in biochemistry, as they are common linkages in carbohydrates and lignin.

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

N,N-Dimethylaniline (DMA) is an organic chemical compound, a substituted derivative of aniline. It consists of a tertiary amine, featuring dimethylamino group attached to a phenyl group. This oily liquid is colourless when pure, but commercial samples are often yellow. It is an important precursor to dyes such as crystal violet.

The Friedel–Crafts reactions are a set of reactions developed by Charles Friedel and James Crafts in 1877 to attach substituents to an aromatic ring. Friedel–Crafts reactions are of two main types: alkylation reactions and acylation reactions. Both proceed by electrophilic aromatic substitution.

In organic chemistry, a carbanion is an anion in which carbon is trivalent and bears a formal negative charge.

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

Triphenylmethane, or triphenyl methane, is the hydrocarbon with the formula (C6H5)3CH. This colorless solid is soluble in nonpolar organic solvents and not in water. Triphenylmethane is the basic skeleton of many synthetic dyes called triarylmethane dyes, many of them are pH indicators, and some display fluorescence. A trityl group in organic chemistry is a triphenylmethyl group Ph3C, e.g. triphenylmethyl chloride (trityl chloride) and the triphenylmethyl radical (trityl radical).

In organic chemistry, the Michael reaction or Michael addition is a reaction between a Michael donor and a Michael acceptor to produce a Michael adduct by creating a carbon-carbon bond at the acceptor's β-carbon. It belongs to the larger class of conjugate additions and is widely used for the mild formation of carbon-carbon bonds.

The Claisen condensation is a carbon–carbon bond forming reaction that occurs between two esters or one ester and another carbonyl compound in the presence of a strong base, resulting in a β-keto ester or a β-diketone. It is named after Rainer Ludwig Claisen, who first published his work on the reaction in 1887.

<i>tert</i>-Butyl alcohol Chemical compound

tert-Butyl alcohol is the simplest tertiary alcohol, with a formula of (CH3)3COH (sometimes represented as t-BuOH). Its isomers are 1-butanol, isobutanol, and butan-2-ol. tert-Butyl alcohol is a colorless solid, which melts near room temperature and has a camphor-like odor. It is miscible with water, ethanol and diethyl ether.

(<i>E</i>)-Stilbene Chemical compound

(E)-Stilbene, commonly known as trans-stilbene, is an organic compound represented by the condensed structural formula C6H5CH=CHC6H5. Classified as a diarylethene, it features a central ethylene moiety with one phenyl group substituent on each end of the carbon–carbon double bond. It has an (E) stereochemistry, meaning that the phenyl groups are located on opposite sides of the double bond, the opposite of its geometric isomer, cis-stilbene. Trans-stilbene occurs as a white crystalline solid at room temperature and is highly soluble in organic solvents. It can be converted to cis-stilbene photochemically, and further reacted to produce phenanthrene.

<span class="mw-page-title-main">Carbenium ion</span> Class of ions

A carbenium ion is a positive ion with the structure RR′R″C+, that is, a chemical species with a trivalent carbon that bears a +1 formal charge.

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

The triphenylmethyl radical (often shorted to trityl radical) is an organic compound with the formula (C6H5)3C. It is a persistent radical. It was the first radical ever to be described in organic chemistry. Because of its accessibility, the trityl radical has been heavily exploited.

<span class="mw-page-title-main">Grignard reagent</span> Organometallic compounds used in organic synthesis

A Grignard reagent or Grignard compound is a chemical compound with the general formula R−Mg−X, where X is a halogen and R is an organic group, normally an alkyl or aryl. Two typical examples are methylmagnesium chloride Cl−Mg−CH3 and phenylmagnesium bromide (C6H5)−Mg−Br. They are a subclass of the organomagnesium compounds.

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

Methyllithium is the simplest organolithium reagent with the empirical formula CH3Li. This s-block organometallic compound adopts an oligomeric structure both in solution and in the solid state. This highly reactive compound, invariably used in solution with an ether as the solvent, is a reagent in organic synthesis as well as organometallic chemistry. Operations involving methyllithium require anhydrous conditions, because the compound is highly reactive toward water. Oxygen and carbon dioxide are also incompatible with MeLi. Methyllithium is usually not prepared, but purchased as a solution in various ethers.

<span class="mw-page-title-main">Organomercury chemistry</span> Group of chemical compounds containing mercury

Organomercury chemistry refers to the study of organometallic compounds that contain mercury. Typically the Hg–C bond is stable toward air and moisture but sensitive to light. Important organomercury compounds are the methylmercury(II) cation, CH3Hg+; ethylmercury(II) cation, C2H5Hg+; dimethylmercury, (CH3)2Hg, diethylmercury and merbromin ("Mercurochrome"). Thiomersal is used as a preservative for vaccines and intravenous drugs.

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

Phenylmagnesium bromide, with the simplified formula C
6
H
5
MgBr
, is a magnesium-containing organometallic compound. It is commercially available as a solution in diethyl ether or tetrahydrofuran (THF). Phenylmagnesium bromide is a Grignard reagent. It is often used as a synthetic equivalent for the phenyl "Ph" synthon.

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

Triphenylmethyl chloride or trityl chloride (TrCl) is a white solid with the chemical formula C19H15Cl. It is an alkyl halide, sometimes used to introduce the trityl protecting group.

Organosodium chemistry is the chemistry of organometallic compounds containing a carbon to sodium chemical bond. The application of organosodium compounds in chemistry is limited in part due to competition from organolithium compounds, which are commercially available and exhibit more convenient reactivity.

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

Triphenylmethylhexafluorophosphate is an organic salt with the formula C
19
H
15
F
6
P
or (C
6
H
5
)
3
CPF
6
, consisting of the triphenylmethyl cation [(C
6
H
5
)
3
C]+
and the hexafluorophosphate anion [PF
6
]
.

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

Phenylsodium C6H5Na is an organosodium compound. Solid phenylsodium was first isolated by Nef in 1903. Although the behavior of phenylsodium and phenyl magnesium bromide are similar, the organosodium compound is very rarely used.

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

In chemistry, triphenylcarbenium, triphenylmethyl cation, tritylium , or trityl cation is an ion with formula [C19H15]+ or (C6H5)3C+, consisting of a carbon atom with a positive charge connected to three phenyl groups. It is a charged version of the triphenylmethyl radical (C6H5)3C•. The name is often abbreviated to triphenylmethyl or trityl in salts, although these names also denote the chemical group in compounds like triphenylmethyl chloride that do not contain the cation.

References

  1. 1 2 Gessner, Thomas; Mayer, Udo (2000). "Triarylmethane and Diarylmethane Dyes". Ullmann's Encyclopedia of Industrial Chemistry . Weinheim: Wiley-VCH. doi:10.1002/14356007.a27_179.
  2. Aug. Kekulé and A. Franchimont (1872) "Ueber das Triphenylmethan" (On triphenylmethane), Berichte der deutschen chemischen Gesellschaft, 5 : 906-908.
  3. W. Hemilian (1874) "Synthese des Triphenylmethans und des Methyl-phenyl-diphenylmethans" (Synthesis of triphenylmethane and of methyl-phenyl-diphenylmethane), Berichte der deutschen chemischen Gesellschaft, 7 : 1203–1210 ; see pp. 1206–1207.
  4. Rodríguez Tzompantzi, Tomasa; Amaro Hernández, Aldo Guillermo; Meza-León, Rosa Luisa; Bernès, Sylvain (2019). "Deciphering the Hydrogen-Bonding Scheme in the Crystal Structure of Triphenylmethanol: A Tribute to George Ferguson and Co-workers". Acta Crystallographica Section C: Structural Chemistry. 75 (9): 1266–1273. doi:10.1107/S2053229619010714. PMC   6727172 . PMID   31484815.
  5. W. E. Bachmann. "Triphenylchloromethane". Organic Syntheses . 23. doi:10.15227/orgsyn.023.0100.
  6. Bryant E. Rossiter and Michael O. Frederick "Triphenylmethyl Hydroperoxide" E-EROS Encyclopedia of Reagents for Organic Synthesis, 2013. doi : 10.1002/047084289X.rt363m.pub2
  7. W. E. Bachmann and H. P. Hetzner. "Triphenylcarbinol". Organic Syntheses .; Collective Volume, vol. 3, p. 839
  8. Latimer, Devin (2007). "The GC–MS Observation of Intermediates in a Stepwise Grignard Addition Reaction". J. Chem. Educ. 84 (4): 699. Bibcode:2007JChEd..84..699L. doi:10.1021/ed084p699.