Related Experiment Video
Updated: Jun 6, 2026
05:41
Photochemical Oxidative Growth of Iridium Oxide Nanoparticles on CdSe@CdS Nanorods
Published on: February 11, 2016
A theoretical study on small iridium clusters: structural evolution, electronic and magnetic properties, and
Jiguang Du1, Xiyuan Sun, Jun Chen
1Institute of Atomic and Molecular Physics, Sichuang University, Chengdu, Sichuan 610065, China.
The Journal of Physical Chemistry. A
|November 20, 2010
Summary
This study reveals new stable iridium cluster structures and their electronic properties. Even-sized iridium clusters are more stable, with specific atoms showing high reactivity for chemical reactions.
Area of Science:
- Computational chemistry
- Materials science
- Condensed matter physics
Background:
- Understanding the properties of transition metal clusters is crucial for catalysis and materials design.
- Iridium clusters exhibit complex structural, electronic, and magnetic behaviors that are size-dependent.
Purpose of the Study:
- To investigate the structural, electronic, and magnetic properties of iridium clusters (Ir(n), n=2-15).
- To identify novel, more stable isomers for specific iridium cluster sizes.
- To analyze the reactive site selectivity of these clusters.
Main Methods:
- Generalized Gradient Approximation (GGA) of Density Functional Theory (DFT) for electronic structure calculations.
- Analysis of structural evolution patterns, stability, and magnetic moments.
- Application of condensed Fukui functions to determine reactive site selectivity.
Main Results:
- A simple cube evolution pattern was observed for Ir(2-15) clusters.
- New, more stable isomers were discovered for Ir(10) and Ir(11) clusters.
- Even-sized iridium clusters demonstrated higher stability than odd-sized ones.
- Covalent character was identified in Ir-Ir bonds of cubic Ir(8) and Ir(12) clusters.
- Magnetic moments decreased sharply from n=8, showing 5d character.
- Specific capped atoms in Ir(9), Ir(10), Ir(11), and Ir(13) exhibited high reactivity for both nucleophilic and electrophilic attacks.
Conclusions:
- The study provides insights into the structural preferences and electronic properties of iridium clusters.
- Novel stable isomers and reactive sites were identified, offering potential for targeted applications.
- The findings contribute to the fundamental understanding of transition metal cluster behavior.
More Related Videos
09:45Accessing Valuable Ligand Supports for Transition Metals: A Modified, Intermediate Scale Preparation of 1,2,3,4,5-Pentamethylcyclopentadiene
Published on: March 20, 2017
10:22In Situ SIMS and IR Spectroscopy of Well-defined Surfaces Prepared by Soft Landing of Mass-selected Ions
Published on: June 16, 2014
Related Concept Videos
02:54Trends in Lattice Energy: Ion Size and Charge
An ionic compound is stable because of the electrostatic attraction between its positive and negative ions. The lattice energy of a compound is a measure of the strength of this attraction. The lattice energy (ΔHlattice) of an ionic compound is defined as the energy required to separate one mole of the solid into its component gaseous ions. For the ionic solid sodium chloride, the lattice energy is the enthalpy change of the process:
02:58Crystal Field Theory - Octahedral Complexes
Crystal Field Theory
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...
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...
02:46Electron Configurations
Electron configurations and orbital diagrams can be determined by applying the Aufbau principle (each added electron occupies the subshell of lowest energy available), Pauli exclusion principle (no two electrons can have the same set of four quantum numbers), and Hund’s rule of maximum multiplicity (whenever possible, electrons retain unpaired spins in degenerate orbitals).
The relative energies of the subshells determine the order in which atomic orbitals are filled (1s, 2s, 2p, 3s, 3p, 4s,...
The relative energies of the subshells determine the order in which atomic orbitals are filled (1s, 2s, 2p, 3s, 3p, 4s,...
03:02Colors and Magnetism
Color in Coordination Complexes
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.
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.
03:10Ionic Radii
Ionic radius is the measure used to describe the size of an ion. A cation always has fewer electrons and the same number of protons as the parent atom; it is smaller than the atom from which it is derived. For example, the covalent radius of an aluminum atom (1s22s22p63s23p1) is 118 pm, whereas the ionic radius of an Al3+ (1s22s22p6) is 68 pm. As electrons are removed from the outer valence shell, the remaining core electrons occupying smaller shells experience a greater effective nuclear...
02:58Properties of Transition Metals
Transition metals are defined as those elements that have partially filled d orbitals. As shown in Figure 1, the d-block elements in groups 3–12 are transition elements. The f-block elements, also called inner transition metals (the lanthanides and actinides), also meet this criterion because the d orbital is partially occupied before the f orbitals.