Related Experiment Video
Updated: Aug 2, 2026

The Synthesis, Characterization and Reactivity of a Series of Ruthenium N-triphosPh Complexes
Published on: April 10, 2015
2,9-Di-(2'-pyridyl)-1,10-phenanthroline: a tetradentate ligand for Ru(II)
Ruifa Zong1, Randolph P Thummel
1Department of Chemistry, University of Houston, Houston, TX 77204-5003, USA.
Abstract:
The tetradentate ligand 2,9-di-(2'-pyridyl)-1,10-phenanthroline is synthesized in 62% yield by the Stille coupling of 2,9-dichloro-1,10-phenanthroline and 2-(tri-n-butylstannyl)pyridine. Treatment of this ligand with RuCl3.3H2O and a 4-substituted pyridine results in the formation of a complex in which the tetradentate ligand occupies the equatorial plane and two pyridines are bound axially. The interior N-Ru-N angles vary from 76.1 degrees to 125.6 degrees , showing considerable distortion from the 90 degrees ideal. The lowest energy electronic transition is sensitive to the electronegativity of the 4-substituent on the axial pyridines, varying from 516 nm for the CF3 group to 580 nm for the NMe2. The oxidation potentials mirror this trend, spanning a range of 1.36-1.03 V, while the reduction potentials show less variation (-0.97 to -1.08 V). The complexes are nonemissive, presumably due to competitive nonradiative processes caused by distortion of the system.
More Related Videos
Related Concept Videos
Metal-Ligand Bonds
In these complexes, transition metals form coordinate covalent bonds, a kind of Lewis acid-base interaction in which both of the electrons in the bond are contributed by a donor (Lewis base) to an electron acceptor (Lewis acid). The Lewis acid in...
Coordination Number and Geometry
Valence Bond Theory
Crystal 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...
Crystal 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,...
Aromatic Hydrocarbon Cations: Structural Overview
Removing one hydrogen from the intervening CH2 group with both...

