Related Experiment Video
Updated: Jul 3, 2026

Construction and Systematical Symmetric Studies of a Series of Supramolecular Clusters with Binary or Ternary Ammonium Triphenylacetates
Published on: February 15, 2016
Hydrogen-bonding interactions in (3,4-dimethoxyphenyl)acetic acid monohydrate
Barbara Hachuła1, Maria Nowak, Joachim Kusz
1Institute of Chemistry, University of Silesia, 14th Bankowa Street, 40-006 Katowice, Poland. bhachula@o2.pl
Abstract:
The crystal structure of the title compound, C(10)H(12)O(4).H(2)O, consists of (3,4-dimethoxyphenyl)acetic acid and water molecules linked by O-H...O hydrogen bonds to form cyclic structures with graph-set motifs R(1)(2)(5) and R(4)(4)(12). These hydrogen-bond patterns result in a three-dimensional network with graph-set motifs R(4)(4)(20) and R(4)(4)(22), and the formation of larger macrocycles, respectively. The C-C bond lengths and the endocyclic angles of the benzene ring show a noticeable asymmetry, which is connected with the charge-transfer interaction of the carboxyl or methoxy groups and the benzene ring. The title compound is one of the simple carboxylic acid systems that form hydrates. Thus, the significance of this study lies in the analysis of the interactions in this structure and the aggregations occurring via hydrogen bonds in two crystalline forms of (3,4-dimethoxyphenyl)acetic acid, namely the present hydrate and the anhydrous form [Chopra, Choudhury & Guru Row (2003). Acta Cryst. E59, o433-o434]. The correlation between the IR spectrum of this compound and its structural data are also discussed.
Related Concept Videos
Hydrogen Bonds
Hydrogen Bonds
Physical Properties of Carboxylic Acids
Structures of Carboxylic Acid Derivatives
Carboxylic acid derivatives contain an acyl group attached to a heteroatom such as chlorine, oxygen, or nitrogen. The carbonyl carbon and oxygen are both sp2-hybridized with an unhybridized p orbital.
The three sp2 orbitals of the carbonyl carbon form three σ bonds, one each with the carbonyl oxygen, the α carbon, and the heteroatom, whereas the other two sp2 orbitals of the carbonyl oxygen are occupied by the lone pairs. Further, the unhybridized p...
Regioselectivity and Stereochemistry of Acid-Catalyzed Hydration
Acid Strength and Molecular Structure
In the absence of any leveling effect, the acid strength of binary compounds of hydrogen with nonmetals (A) increases as the H-A bond strength decreases down a group in the periodic table. For group 17, the order of increasing acidity is HF < HCl < HBr < HI. Likewise, for group 16, the order of increasing acid strength is H2O < H2S < H2Se < H2Te. Across a row in the periodic table, the acid strength of binary hydrogen compounds increases with increasing...

