Do intramolecular bonds vibrate in solids ?

In summary, the conversation discusses whether intramolecular bonds vibrate in solids and if these vibrations are similar to those in gas and liquid phases. It is mentioned that while intermolecular vibrations are well-known, the existence of intramolecular vibrations in solids, known as "optical phonons", is also confirmed. It is also noted that the energy gaps between different vibrational states in solids may be different from those in gases and liquids due to interactions between molecules.
  • #1
ns_phonon
47
0
Do intramolecular bonds vibrate in solids...?

In case of molecular solids does the Intramolecular bonds(bonds within atoms of a molecule) vibrate as they do vibrate in gas and liquid phases.

We are familiar that motion of molecules in solids is in form of vibrations. But when we talk of that we are normally speaking about inter-molecular vibrations(phonons)

Now, we know that intermolecular bonds are held together by weak forces like Van Der Walls' forces,London Dispersive forces,etc. While the intra-molecular forces are generally strong forces like covalent bonding,dipole-dipole forces,etc.

"Also when we heat a solid(of molecular nature), it is easy to envisage that intermolecular vibrations increases. But on heating does intra-molecular vibrational transtions to higher vibrational energy states also takes place as on heating a gas comprised of molecules."


"Also does the energy gap between various intramolecular vibrational states(If they exist) in solids , remains the same as the energy gap between different vibrational levels in gases and liquids.?"


"Thanks For Reading and Paying Attention"​
 
Physics news on Phys.org
  • #2
Yes, they are called "optical phonons" in solids. Due to their interaction they no longer occur at sharp frequencies but are broardened out into bands.
 

1. Do intramolecular bonds vibrate in solids?

Yes, intramolecular bonds do vibrate in solids. This is because the atoms in a solid are still connected by covalent bonds, which have a certain amount of flexibility and can vibrate at different frequencies.

2. How does the vibration of intramolecular bonds affect the properties of solids?

The vibration of intramolecular bonds can affect the properties of solids in various ways. It can influence the density, thermal conductivity, and melting point of a solid, among other things. It can also contribute to the mechanical strength and stiffness of a material.

3. Are all intramolecular bonds in a solid vibrating at the same frequency?

No, not all intramolecular bonds in a solid vibrate at the same frequency. The frequency of vibration depends on factors such as the strength of the bond, the mass of the atoms involved, and the temperature of the solid.

4. Can intramolecular bonds in a solid stop vibrating?

Yes, intramolecular bonds in a solid can stop vibrating if the temperature of the solid is reduced to absolute zero (0 Kelvin). At this temperature, the atoms are motionless, and there is no thermal energy to sustain the vibration of the bonds.

5. How do scientists study the vibration of intramolecular bonds in solids?

Scientists use various techniques to study the vibration of intramolecular bonds in solids. One common method is infrared spectroscopy, which measures the absorption of infrared light by the bonds. Other techniques include Raman spectroscopy, neutron scattering, and X-ray diffraction.

Similar threads

  • Atomic and Condensed Matter
Replies
9
Views
2K
  • Atomic and Condensed Matter
3
Replies
83
Views
4K
  • High Energy, Nuclear, Particle Physics
Replies
12
Views
1K
  • Atomic and Condensed Matter
Replies
5
Views
2K
  • Thermodynamics
Replies
3
Views
748
  • Atomic and Condensed Matter
Replies
2
Views
1K
  • Mechanics
Replies
2
Views
1K
  • Atomic and Condensed Matter
Replies
9
Views
2K
Back
Top