Related Experiment Video
Updated: Apr 17, 2026
Synthesis and Characterization of Functionalized Metal-organic Frameworks
Published on: September 5, 2014
Synthesis, characterization and oscillator-vibrated near-infrared (NIR) luminescence of two pseudo-polymorphic
Zhao Zhang1, Heini Feng1, Lin Liu1
1School of Chemical Engineering, Shaanxi Key Laboratory of Degradable Medical Material, Northwest University, Xi'an 710069, Shaanxi, China.
Abstract:
Through the self-assembly of the (OH)2-Salophen H4L (H4L=N,N'-bis(3-hydroxylsalicylidene)benzene-1,2-diamine) with LnCl3·6H2O or Ln(NO3)3·6H2O (Ln=La, Yb or Gd) in different solvent systems MeCN-EtOH and MeCN-DMF, the mixed (L)(4-) and (H2L)(2-) coordination modes induce the formation of anion-independent while pseudo-polymorphic homoleptic linear tetranuclear complexes [Ln4(H2L)2(L)2(EtOH)2] (Ln=La, 1; Ln=Yb, 2 or Ln=Gd, 3) and [Ln4(H2L)2(L)2(DMF)2] (Ln=La, 4; Ln=Yb, 5 or Ln=Gd, 6), respectively. The result of their photophysical properties shows the characteristic NIR luminescence for both Yb(3+)-based complexes 2 and 5 with emissive lifetimes in microsecond ranges, while the difference of nearby and/or distant oscillator-based (OH and/or CH) vibrations from two coordinated EtOH or DMF molecules within the inner coordination spheres of Yb(3+) ions in the two complexes has a decisive effect on their NIR luminescent properties.
More Related Videos
13:51Synthesis of Core-shell Lanthanide-doped Upconversion Nanocrystals for Cellular Applications
Published on: November 10, 2017
12:51A 'Plug and Play' Method to Create Water-dispersible Nanoassemblies Containing an Amphiphilic Polymer, Organic Dyes and Upconverting Nanoparticles
Published on: November 14, 2015
Related Concept Videos
02:46Crystal Field Theory - Tetrahedral and Square Planar Complexes
Crystal field theory (CFT) is applicable to molecules in geometries other than octahedral. In octahedral complexes, the lobes of the dx2−y2 and dz2 orbitals point directly at the ligands. For tetrahedral complexes, the d orbitals remain in place, but with only four ligands located between the axes. None of the orbitals points directly at the tetrahedral ligands. However, the dx2−y2 and dz2 orbitals (along the Cartesian axes) overlap with the ligands less than...
02:42Valence Bond Theory
02:58Crystal Field Theory - Octahedral Complexes
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
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...
01:21Polymer Classification: Crystallinity
Crystalline domains are the regions where polymer chains are aligned in an orderly manner and held together in proximity by intermolecular forces. For example, chains in the crystalline domains of polyethylene and nylon are bound together by van der Waals...
01:26Polymer Classification: Stereospecificity