Tetraphenylmethane

Tetraphenylmethane

Names

Preferred IUPAC name

1,1′,1′′,1′′′-Methanetetrayltetrabenzene

Identifiers

CAS Number

630-76-2^Y

3D model (JSmol)

Interactive image

ChemSpider

11917^Y

ECHA InfoCard

100.010.132

EC Number

211-144-0

PubChem CID

12424

UNII

CM2Q9C446P^Y

CompTox Dashboard (EPA)

DTXSID30212215

InChI

InChI=1S/C25H20/c1-5-13-21(14-6-1)25(22-15-7-2-8-16-22,23-17-9-3-10-18-23)24-19-11-4-12-20-24/h1-20H^Y
Key: PEQHIRFAKIASBK-UHFFFAOYSA-N^Y
InChI=1/C25H20/c1-5-13-21(14-6-1)25(22-15-7-2-8-16-22,23-17-9-3-10-18-23)24-19-11-4-12-20-24/h1-20H
Key: PEQHIRFAKIASBK-UHFFFAOYAS

SMILES

c1ccccc1C(c2ccccc2)(c3ccccc3)c4ccccc4

Properties

Chemical formula

C₂₅H₂₀

Molar mass

320.44 g/mol

Melting point

282 °C (540 °F; 555 K)

Boiling point

431 °C

Structure^[1]

tetragonal

P42₁c, No. 114

S₄

a = 10.896 Å, c = 7.280 Å

(20 °C)

Formula units (Z)

Hazards

GHS labelling:

Pictograms

Signal word

Danger

Hazard statements

H350

Precautionary statements

P201, P202, P281, P308+P313, P405, P501

Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

verify (what is ^YN ?)

Infobox references

Tetraphenylmethane is an organic compound consisting of a methane core with four phenyl substituents. It was first synthesized by Moses Gomberg in 1898.

YouTube Encyclopedic

1/3
Views:
727
51 881
3 718

Transcription

Synthesis

Gomberg's classical organic synthesis shown below starts by reacting triphenylmethyl bromide 1 with phenylhydrazine 2 to the hydrazine 3. Oxidation with nitrous acid then produces the azo compound 4 from which on heating above the melting point, nitrogen gas evolves with formation of tetraphenylmethane 5.^[2]

Gomberg was able to distinguish this compound from triphenylmethane (elemental analysis was not an option given the small differences in the hydrogen fractions of 6.29% and 6.60%) by nitration of 5 with nitric acid to 6. A strong base would be able to abstract the methine proton of the nitrated triphenylmethyl compound if present, forming a strongly colored compound.

He obtained further evidence for the formation of tetraphenylmethane by reducing the nitro groups to amino groups with zinc dust in acetic acid to the leuco dye 7, which on exposure to hydrochloric acid eliminates aniline to the known compound pararosaniline 8.

Gomberg's success in synthesizing tetraphenylmethane set him on the attempt to prepare the next homologue hexaphenylethane, which led him to the discovery of the triphenylmethyl radical.

References

^ Robbins, A.; Jeffrey, G. A.; Chesick, J. P.; Donohue, J.; Cotton, F. A.; Frenz, B. A.; Murillo, C. A. (1975-10-01). "A refinement of the crystal structure of tetraphenylmethane: three independent redeterminations". Acta Crystallographica Section B: Structural Crystallography and Crystal Chemistry. 31 (10): 2395–2399. Bibcode:1975AcCrB..31.2395R. doi:10.1107/S0567740875007686. ISSN 0567-7408.
^ Gomberg, M. (1898). "On tetraphenylmethane". J. Am. Chem. Soc. 20 (10): 773–780. doi:10.1021/ja02072a009.

This page was last edited on 11 February 2024, at 04:43

From Wikipedia, the free encyclopedia

YouTube Encyclopedic

Transcription

Synthesis

See also

References