Related Experiment Video
Updated: Jun 27, 2026
Hyperspectral Imaging as a Tool to Study Optical Anisotropy in Lanthanide-Based Molecular Single Crystals
Published on: April 14, 2020
Molecular construction, characterization, and photophysical properties of supramolecular lanthanide-calix[4]arene
Bing Yan1, Qian-Ming Wang, Dong-Jie Ma
1Department of Chemistry, Tongji University, Siping Road 1239 Shanghai 200092, China. byan@tongji.edu.cn
Abstract:
Hydroxyl groups of the macrocyclic compound p-tert-butylcalix[4]arene have been converted into urethanesil (-NH(C=O)O-)-grafted bridges through a hydrogen transfer nucleophilic addition reaction. Subsequently, the modified macrocyclic derivative can coordinate to lanthanide ions (Tb, Eu) effectively and form a hybrid framework after the cohydrolysis and copolycondensation process through the triethoxysilane components. The above sol-gel-derived inorganic-organic supramolecular hybrids are analyzed under infrared spectroscopy, ultraviolet absorption, and luminescence spectroscopy for interpretation of their photophysical properties. Spectroscopic data point out that the modified calix[4]arene could sensitize diverse lanthanide ions to exhibit attractive green and red luminescence. It is noted that the triplet energy level of this particular macrocyclic bridged ligand is more suitable for the emissive energy level of Tb(3+) ions than the Eu(3+) ions. The luminescent lifetimes and quantum yields of europium hybrids are discussed, and the number of water molecules coordinated to Eu(3+) is estimated.
Related Concept Videos
02:42Valence Bond Theory
03:02Colors and Magnetism
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human eye.
01:27¹H NMR: Long-Range Coupling
In alkenes, spin information is communicated via σ–π overlap, as seen in allylic (four-bond) and homoallylic (five-bond) couplings. These coupling interactions are stronger when the σ bond is parallel to the alkene π orbitals.
![[4+2] Cycloaddition of Conjugated Dienes: Diels–Alder Reaction](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2Ffiles%2Fmedia%2Fscience-education%2Fscience-education-thumbs%2F12417.jpg&w=3840&q=75)
01:16[4+2] Cycloaddition of Conjugated Dienes: Diels–Alder Reaction
02:34Structural Isomerism
Isomers are different chemical species that have the same chemical formula. Structural isomerism of coordination compounds can be divided into two subcategories, the linkage isomers and coordination-sphere isomers.
Linkage isomers occur when the coordination compound contains a ligand that can bind to the transition metal center through two different atoms. For example, the CN− ligand can bind through the carbon atom or through the nitrogen atom. Similarly, SCN− can be...
02:52Stereoisomerism
Isomers are different chemical species that have the same chemical formula.
Transition metal complexes often exist as geometric isomers, in which the same atoms are connected through the same types of bonds but with differences in their orientation in space. Coordination complexes with two different ligands in the cis and trans positions from a ligand of interest form isomers. For example, the octahedral [Co(NH3)4Cl2]+ ion has two isomers (Figure 1) In the cis...