Related Experiment Video
Updated: Jun 24, 2026
Synthesis of Triazole and Tetrazole-Functionalized Zr-Based Metal-Organic Frameworks Through Post-Synthetic Ligand Exchange
Published on: June 23, 2023
Synthesis, characterization, and electro-optical properties of Zn(II) complexes with pi-conjugated terpyridine
Andreas Winter1, Christian Friebe, Manuela Chiper
1Laboratory of Macromolecular Chemistry and Nanoscience, Eindhoven University of Technology, P. O. Box 513, 5600 MB Eindhoven, The Netherlands.
Abstract:
A series of nine zinc(II) complexes containing substituted 4'-phenyl-2,2':6',2''-terpyridines as ligands is synthesized and fully characterized. The ground-state structures of four examples are calculated by means of DFT and their structural features are confirmed by experimental Raman spectroscopy. Special focus is placed on the degree of pi-electron delocalization between the terpyridine unit and the attached phenyl moiety. Applying Bader's quantum theory of atoms in molecules (QTAIM) and visualizing the electron-density distribution by intermolecular Deltarho plots reveals an increase in ellipticity-and therefore pi-electron delocalization-for phenylvinyl-substituted derivatives compared to phenylethynyl-substituted ones. Experimentally, this is verified by spectroscopic means, because an increase in ellipticity goes along with a pronounced decrease of the HOMO-LUMO energy band gap. Overall, the lateral pi-conjugated substituents are found to strongly influence the electro-optical properties of the complexes. In solution, the color of emission can be modulated from violet to cyan (425-487 nm) and high quantum yields (Phi(PL) up to 0.60) are observed. Thin solid films of the complexes in a matrix of poly(methyl methacrylate) have been inkjet-printed, and their photophysical behavior (bright emission, Phi(PL) up to 0.30) reveals their potential as new emissive materials for applications in light-emitting devices.
More Related Videos
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 the dxy,...
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...
02:42Valence Bond Theory
01:26Photochemical Electrocyclic Reactions: Stereochemistry
Selection Rules: Photochemical Activation
01:17Thermal Electrocyclic Reactions: Stereochemistry
Selection Rules: Thermal Activation
Conjugated systems containing an even number of π-electron pairs undergo a conrotatory ring closure. For example, thermal electrocyclization of (2E,4E)-2,4-hexadiene, a conjugated diene containing two π-electron pairs, gives trans-3,4-dimethylcyclobutene.
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...