Related Experiment Video
Updated: Aug 7, 2026
13:21
Preparation, Purification, and Characterization of Lanthanide Complexes for Use as Contrast Agents for Magnetic Resonance Imaging
Published on: July 21, 2011
(Nitrato-kappa2O,O')bis(triethanolamine-kappa4N,O,O',O'')lanthanum(III) dinitrate
Adrian Fowkes1, William T A Harrison
1Department of Chemistry, University of Aberdeen, Meston Walk, Aberdeen AB24 3UE, Scotland.
Summary
This study describes the crystal structure of a lanthanum-triethanolamine compound. The structure features one-dimensional chains, and the ligand
Area of Science:
- Inorganic Chemistry
- Crystallography
- Materials Science
Background:
- Lanthanum (La) complexes with organic ligands are of interest for various applications.
- Triethanolamine (TEA) is a versatile ligand capable of coordinating with different metal ions.
Purpose of the Study:
- To elucidate the crystal structure of the lanthanum nitrate complex with triethanolamine.
- To investigate the coordination behavior of triethanolamine with lanthanum.
Main Methods:
- Single-crystal X-ray diffraction analysis.
- Characterization of the crystal structure and bonding interactions.
Main Results:
- The title compound, [La(NO3)(C6H15NO3)2](NO3)2, was synthesized and characterized.
- The crystal structure reveals a network of [La(NO3)(C6H15NO3)2]2+ cations and nitrate counter-ions.
- Cation-anion hydrogen bonds (O-H...O) lead to a one-dimensional structural motif.
- The lanthanum atom is ten-coordinate, and a nitrate anion exhibits site symmetry 2.
Conclusions:
- Triethanolamine can coordinate with diverse metal cations like Li+ and La3+.
- This broad binding capability of triethanolamine may limit its use in applications requiring selective metal ion binding.
Related Concept Videos
01:261° Amines to Diazonium or Aryldiazonium Salts: Diazotization with NaNO2 Overview
Nitrous acid and nitric acids are two types of acids containing nitrogen, among which nitrous acid is weaker than nitric acid. Nitrous acid with a pKa value of 3.37 ionizes in water to give a nitrite ion and the hydronium ion.
The nitrous acid is unstable. Hence, it is formed in situ from a solution of sodium nitrite and cold aqueous acids such as hydrochloric or sulfuric acid. In an acidic solution, the –OH group of nitrous acid undergoes protonation to give oxonium ion, followed by water loss...
The nitrous acid is unstable. Hence, it is formed in situ from a solution of sodium nitrite and cold aqueous acids such as hydrochloric or sulfuric acid. In an acidic solution, the –OH group of nitrous acid undergoes protonation to give oxonium ion, followed by water loss...
01:202° Amines to N-Nitrosamines: Reaction with NaNO2
Secondary amines react with nitrous acid to form N-nitrosamines, as depicted in Figure 1. Nitrous acid, a weak and unstable acid, is formed in situ from an aqueous solution of sodium nitrite and strong acids, such as hydrochloric acid or sulfuric acid, in cold conditions. In the presence of an acid, the nitrous acid gets protonated. The subsequent loss of water results in the formation of the electrophile known as nitrosonium ion.
00:43Complexometric Titration: Ligands
Different monodentate and polydentate ligands are used as complexing agents in complexometric titration reactions. The formation of complexes by mono- and bidentate ligands involves two or more intermediate steps, limiting their use as complexing agents. In comparison, polydentate ligands can form complexes with metal ions in a single-step process, facilitating sharper end points. This means polydentate ligands, such as amino carboxylic acid derivatives, are most commonly employed in...
03:46Qualitative Analysis
For solutions containing mixtures of different cations, the identity of each cation can be determined by qualitative analysis. This technique involves a series of selective precipitations with different chemical reagents, each reaction producing a characteristic precipitate for a specific group of cations. Metal ions within a group are further separated by varying the pH, heating the mixture to redissolve a precipitate, or adding other reagents to form complex ions.
For instance, group IV...
For instance, group IV...
01:22EDTA: Chemistry and Properties
Polydentate ligands are most widely used in complexometric titrations because they form more stable complexes with the metal ions than mono- or bidentate ligands due to the chelate effect. Examples of polydentate ligands are ethylenediaminetetraacetic acid (EDTA), crown ethers, and cryptands. The most important feature of optimal polydentate ligands is the ability to form 1:1 complexes in a single-step process. Amino carboxylic acid derivatives are frequently used as complexing agents. EDTA is...
01:371° Amines to Diazonium or Aryldiazonium Salts: Diazotization with NaNO2 Mechanism
Nitrous acid is a relatively weak and unstable acid prepared in situ by the reaction of sodium nitrite and cold, dilute hydrochloric acid. In an acidic solution, the nitrous acid undergoes protonation when it loses water to form a nitrosonium ion—an electrophile. Nitrous acid reacts with primary amines to give diazonium salts. The reaction is called diazotization of primary amines.