Info om benzenheksakarboksylsyre (mellittsyre)

[Πεισιθάνατος]

Noen som vet noe om denne bindingen? Hvor den forekommer, kjemisk formel, etc.?

 

Jeg skulle anta at den kjemiske formelen ser ut som noe slikt

C6(CO2H)6 men jeg er ikke helt sikker. Jeg kan ikke finne noe særlig info om dette på nettet. Noen som kan hjelpe?

Endret 30. januar 2006 av -Knuð

[endrebjo]

En karboksylsyre (organisk syre) har vel alltid en -COOH-hale, eller?

[Πεισιθάνατος]

En karboksylsyre (organisk syre) har vel alltid en -COOH-hale, eller?

5525019[/snapback]

Benzenheksakarboksylsyre. Altså seks CO2H-haler eller, mer presist og som du skriver, COOH-haler. Husk at det er seks karboksyler, så parentes i formelen er vesentlig.

 

Jeg fant for øvrig noe på wikipedia:

 

Mellitic acid, also called graphitic acid and benzene hexacarboxylic acid, C6(CO2H)6, is an acid first discovered in 1799 by M. H. Klaproth in the mineral honey stone, which is the aluminium salt of the acid. The acid may be prepared by warming honeystone with ammonium carbonate, boiling off the excess of the ammonium salt and adding ammonia to the solution. The precipitated alumina is filtered off, the filtrate evaporated and the ammonium salt of the acid purified by recrystallization. The ammonium salt is then converted into the lead salt by precipitation with lead acetate and the lead salt decomposed by sulfuretted hydrogen. The acid may also be prepared by the oxidation of pure carbon, or of hexamethyl benzene, in the cold, by alkaline potassium permanganate. It crystallizes in fine silky needles and is soluble in water and alcohol. It is a very stable compound, chlorine, concentrated nitric acid and hydriodic acid having no action upon it. It is decomposed, on dry distillation, into carbon dioxide and pyromellitic acid, C10H6O3; when distilled with lime it gives carbon dioxide and benzene. Long digestion of the acid with excess of phosphorus pentachloride results in the formation of the acid chloride, which crystallizes in needles, melting at 190° C. By heating the ammonium salt of the acid to 150-160° C as long as ammonia is evolved, a mixture of paramide (mellimide), C6(CO > NH)3, and ammonium euchroate is obtained. The mixture may be separated by dissolving out the ammonium euchroate with water. Paramide is a white amorphous powder, insoluble in water and alcohol.

 

Formelen min var altså riktig.

 

...men jeg ser også etter litt mer informasjon, som ikke er for tungt formulert.

 

EDIT: Sitatkaos

Endret 31. januar 2006 av -Knuð

[endrebjo]

Argh... jeg var litt trøtt så jeg så ikke at CO2H stod for COOH.