Introduction to the structural formula of adipic acid

Introduction to the structural formula of adipic acid: The structural formula of adipic acid is HOOC (CH ₂) ₄ COOH, which is an organic dicarboxylic acid. The carboxyl groups (- COOH) at both ends give it acidity, and the methylene chain in the middle gives it a certain degree of flexibility and stability.
From a chemical bond perspective, the carbon oxygen double bond (C=O) in the carboxyl group of adipic acid has a length of approximately 0.120nm, while the carbon oxygen single bond (C-O) has a length of approximately 0.134nm. The presence of carboxyl groups allows adipic acid to participate in various reactions such as esterification and salt formation.
The methylene (- CH ₂ -) chain of adipic acid has a carbon carbon single bond (C-C) length of about 0.154nm and a bond angle of about 109.5 °. This structure makes the molecular arrangement of adipic acid relatively regular in the solid state. According to relevant literature, the structural formula of adipic acid determines its physical properties, with a melting point of 152 ℃, which is related to the hydrogen bonding between molecules and the interaction of methylene chains. The carboxyl group in the structural formula of adipic acid has a strong electron withdrawing induction effect, which makes the hydrogen atoms on adjacent methylene groups active and capable of undergoing reactions such as halogenation. In terms of spatial structure, the adipic acid molecule is approximately linear as a whole, with carboxyl groups located at both ends and methylene chains in the middle. This structure is conducive to its blending or copolymerization with some long-chain molecules.
Adipic acid has a certain solubility in water because the carboxyl group in its structural formula can form hydrogen bonds with water molecules. At 25 ℃, approximately 1.5g of adipic acid can be dissolved per 100g of water. The structural formula of adipic acid gives it a certain acidity, with a pKa ₁ of about 4.43 and a pKa ₂ of about 5.41. It can form different salts step by step when reacting with bases. The methylene chain in the structural formula of adipic acid can provide a certain degree of flexibility, which can improve the elasticity and toughness of some polymer materials when synthesized. When adipic acid is heated, the carboxyl group in its structural formula undergoes some thermal decomposition reactions, which may result in decarboxylation of products such as cyclopentanone at high temperatures.
The structural formula of adipic acid affects its solubility in organic solvents, with better solubility in ethanol. At 20 ℃, approximately 160g of adipic acid can be dissolved per 100g of ethanol.