Related Experiment Video
Updated: Oct 2, 2025
09:04
A Direct, Early Stage Guanidinylation Protocol for the Synthesis of Complex Aminoguanidine-containing Natural Products
Published on: September 9, 2016
10.8K
Guanidinium solvents with exceptional hydrogen bond donating abilities
Navneet K Brar1,2, Roland T Brown1,2, Kaveh Shahbaz3
1School of Chemical Sciences, University of Auckland, Auckland, New Zealand. cameron.weber@auckland.ac.nz.
Chemical Communications (Cambridge, England)
|February 23, 2022
Summary
New guanidinium chloride solvents, created using deep eutectic solvent methods, exhibit strong hydrogen-bond donating capabilities. These findings advance our understanding of novel solvent properties and applications.
Area of Science:
- Chemistry
- Materials Science
Background:
- Deep eutectic solvents (DES) offer tunable properties.
- Guanidinium salts are known for their hydrogen-bonding potential.
Purpose of the Study:
- To prepare and characterize guanidinium chloride-based solvents using DES principles.
- To investigate the hydrogen-bond donating abilities and physical properties of these novel solvents.
Main Methods:
- Solvent preparation via deep eutectic solvent methodology.
- Assessment of solvent polarity using various techniques.
- Utilizing a novel 31P NMR chemical shift method to quantify hydrogen-bond donating strength.
Main Results:
- Successfully prepared guanidinium chloride-based solvents.
- Established strong hydrogen-bond donating abilities through multiple polarity measures.
- Demonstrated the utility of a novel 31P NMR method for evaluating solvent polarity.
Conclusions:
- Guanidinium chloride-based solvents possess significant hydrogen-bond donating capabilities.
- These solvents represent a promising new class of materials for various chemical applications.
- The study provides insights into the fundamental properties governing these DES.
Related Concept Videos
01:04Hydrogen Bonds
10.9K
A hydrogen bond is formed when a weakly positive hydrogen atom already bonded to one electronegative atom (for example, the oxygen in the water molecule) is attracted to another electronegative atom from another polar molecule, such as water (H2O), hydrogen fluoride (HF), or ammonia (NH3). The huge electronegativity difference between the H atom (2.1) and the atom to which it is bonded (4.0 for an F atom, 3.5 for an O atom, or 3.0 for an N atom), combined with the very small size of an H atom...
10.9K
01:16Titration in Nonaqueous Solvents
1.0K
Most acid-base titrations are performed in an aqueous medium. In aqueous titrations, water competes with weaker acids or bases for proton donation or acceptance, leading to ambiguous endpoints in the titration curve. Water also affects the partial ionization of weak acids or bases. For example, water accepts a proton from acetic acid to form hydronium and acetate ions. The hydronium ion formed is a stronger acid than acetic acid, and the acetate ion is a stronger base than water. As a result,...
1.0K
01:19Diazonium Group Substitution: –OH and –H
2.9K
Nitrous acid, a weak acid, is prepared in situ via the reaction of sodium nitrite with a strong acid under cold conditions. This nitrous acid prepared in situ reacts with primary arylamines to form arenediazonium salts. Such reactions are known as diazotization reactions. As shown in Figure 1, the formation of arenediazonium salts begins with the decomposition of nitrous acid in an acidic solution to give nitrosonium ions.
2.9K
01:25Basicity of Heterocyclic Aromatic Amines
6.3K
Heterocyclic amines, where the N atom is a part of an alicyclic system, are similar in basicity to alkylamines. Interestingly, the heterocyclic amine having a nitrogen atom as part of an aromatic ring has much less basicity than its corresponding alicyclic counterpart. For this reason, as presented in Figure 1, piperidine (pKb = 2.8) is significantly more basic than pyridine (pKb = 8.8).
6.3K
01:32Aldehydes and Ketones with HCN: Cyanohydrin Formation Overview
3.2K
Cyanohydrins are compounds that contain –CN and –OH groups on the same carbon atom. They are formed by the nucleophilic addition of the cyanide ions to the carbonyl group. Cyanide ions are highly basic and nucleophilic and can be generated from HCN under aqueous conditions. However, since HCN is a weak acid, the number of cyanide ions generated is very small. Hence, a small amount of base or KCN/NaCN is added to HCN to increase the concentration of the cyanide ions in the reaction...
3.2K
01:12Solvents
67.7K
A solvent is a substance, most often a liquid, that can dissolve other substances. Here, the substance being dissolved is called a solute. When a solvent and a solute combine, they form a solution - a homogenous mixture of both the solvent and the solute. Water is a universal biological solvent. Its polar structure allows it to dissolve many other polar compounds. The ability of water to dissolve is governed by a balance between water molecules binding to each other and binding to the solute.
A...
A...
67.7K