The system to the right is not a true simple harmonic oscillator. However, it does show oscillatory motion under certain conditions. The system to the right follows the curve of a Morse potential.
Morse potentials are used to model the interaction between two atoms in a diatomic molecule. Atoms oscillate back and forth due to the interplay of forces acting upon the atoms. There is a strong repulsive force that exists when the two atoms are close to one another. This is due to electrostatic repulsion between the two positively charged nuclei as well as the repulsion between inner-orbital electorns. The attractive force becomes the dominant force as the distance increases. If the distance is too great, there is no longer an electric field interaction between the atoms. The energy at this distance corresponds to the dissociation energy of the bond.
In this example of an oscillating system, we have two spheres which exert both a repulsive and attractive force on each other. In this proposed system, repulsive forces are stronger than attractive forces when the spheres are close to each other. The net force, shows the summation of the two forces and how this changes with the distance between the spheres.
balls and arrows
There exists within this system an equilibrium distance where the net force is equal to zero. When the system is disturbed, it will oscillate around this equilibrium position.
Try pushing the spheres together or pulling the spheres apart. Observe the relationship between the two spheres and changes to potential energy. What else do you notice? Try moving the spheres as far away from each other as possible. What happens?
You will see a brief description and will be given a chance to jump directly to that topic
This topic is not currently available.
Physical chemistry attempts to understand chemistry through the physical world and using instrumentation.
Molecular excitation refers to the promotion of an electron to an excited state. This particular pheomenon is extremely important for current scientific discovery, particularly in the biological sciences.
A simple harmonic oscillator displays a very particular type of periodic motion called simple harmonic motion. A common example of a simple harmonic oscillator is a spring that is compressed or stretched.
Morse potentials are used to model the interaction between two atoms in a diatomic molecule.
A diatomic molecule has only two atoms which are connected through a chemical bond. This particular diatomic molecule is double bonded.
The energy of a diatomic molecule can be approximated using a Morse Potential. Quantum effects are not discussed.
The vibrational state of the diatomic molecule refers to the frequency at which the atoms oscillate (ie. the bond stretches and compresses).
A single rotational mode is available to the diatomic molecule and involves rotation around an axis that is perpendicular to the bond axis. The energy of the rotational mode is directly related to its angular momentum.
Electromagnetic radiation is a form of that travels in waves. Specifically, electromagnetic energy travels in a transverse wave that oscillates at a certain frequency.
Like other dipoles, the transition dipole refers to a difference in charge from one location of a molecule to another. The transition dipole occurs when an electron is excited from the ground state to an excited state.
The Jablonski diagram is capable of showing the transition between ground states and excited states by using quantized Morse potentials.
Fluorescence begins with absorption and molecular excitation into an excited state. Once promoted, the electron will fall to the lowest vibrational energy within that excited state.