Diols and dicarboxylic acids are versatile building blocks in the chemical industry for synthesising a wide array of functional organic materials and condensation polymers.
Butane-1,4-diol, HO(CH2)4OH\text{HO(CH}_2)_4\text{OH}HO(CH2)4OH, can be oxidised to form butanedioic acid, HOOC(CH2)2COOH\text{HOOC(CH}_2)_2\text{COOH}HOOC(CH2)2COOH.
State the reagents and conditions required for this oxidation reaction and write a balanced equation for the reaction. In your equation, represent the oxidising agent as [O][\text{O}][O].
Butanedioic acid is highly soluble in water. Explain, with reference to the key intermolecular interactions shown in the diagram below, why butanedioic acid is soluble in water.
Butanedioic acid, HOOC(CH2)2COOH\text{HOOC(CH}_2)_2\text{COOH}HOOC(CH2)2COOH, can react with hexane-1,6-diamine, H2N(CH2)6NH2\text{H}_2\text{N(CH}_2)_6\text{NH}_2H2N(CH2)6NH2, to form the condensation polymer G.
Draw the structure of one repeat unit of polymer G. The amide functional group should be clearly displayed. Show open bonds at both ends of the repeating unit.
Suggest why polymer G is able to biodegrade.
In industrial synthesis, a much higher yield of polymer G is obtained by reacting a diacyl dichloride with hexane-1,6-diamine. The required diacyl dichloride is prepared by reacting butanedioic acid with phosphorus(V) chloride, PCl5\text{PCl}_5PCl5.
Complete the balanced equation for this preparation of the diacyl dichloride:
HOOC(CH2)2COOH+2PCl5→………\text{HOOC(CH}_2)_2\text{COOH} + 2\text{PCl}_5 \rightarrow \dots\dots\dotsHOOC(CH2)2COOH+2PCl5→………