Related Experiment Video
Updated: Mar 19, 2026
06:07
Studying Large Amplitude Oscillatory Shear Response of Soft Materials
Published on: April 25, 2019
13.8K
Stereodynamics in NO(X) + Ar inelastic collisions
M Brouard1, H Chadwick1, S D S Gordon1
1The Department of Chemistry, University of Oxford, The Chemistry Research Laboratory, 12 Mansfield Road, Oxford, OX1 3TA, United Kingdom.
The Journal of Chemical Physics
|June 17, 2016
Summary
Investigating the orientation of nitric oxide (NO) molecules before collisions with argon (Ar) revealed insights into molecular interactions. Quantum mechanics accurately predicted scattering behavior, highlighting interference effects.
Area of Science:
- Chemical Physics
- Molecular Dynamics
- Scattering Theory
Background:
- Understanding molecular orientation effects in collisions is crucial for controlling chemical reactions.
- Previous studies on nitric oxide (NO) collisions with rare gases observed parity pairs.
Purpose of the Study:
- To investigate the influence of NO bond axis orientation on rotationally inelastic collisions with Argon (Ar).
- To compare experimental measurements with quantum mechanical calculations for bond-orientation-resolved differential cross sections.
Main Methods:
- Modified velocity-map imaging ion optics for hexapole state-selected NO orientation.
- Experimental measurement of bond orientation resolved differential cross sections.
- Quantum mechanical and classical theoretical calculations.
Main Results:
- Good agreement between experimental and theoretical results for spin-orbit conserving transitions.
- Absence of parity pairs due to coherent superposition of Λ-doublet levels in the orienting field.
- Differential steric effect depends mainly on the final rotational state, not the Λ-doublet level.
Conclusions:
- Quantum interference, dominated by the repulsive potential region, explains the observed steric asymmetry.
- Classical mechanics cannot quantitatively predict the observed steric asymmetry in NO + Ar collisions.
Related Concept Videos
01:00Elastic Collisions: Introduction
15.4K
An elastic collision is one that conserves both internal kinetic energy and momentum. Internal kinetic energy is the sum of the kinetic energies of the objects in a system. Truly elastic collisions can only be achieved with subatomic particles, such as electrons striking nuclei. Macroscopic collisions can be very nearly, but not quite, elastic, as some kinetic energy is always converted into other forms of energy such as heat transfer due to friction and sound. An example of a nearly...
15.4K
01:15Elastic Collisions: Case Study
21.0K
Elastic collision of a system demands conservation of both momentum and kinetic energy. To solve problems involving one-dimensional elastic collisions between two objects, the equations for conservation of momentum and conservation of internal kinetic energy can be used. For the two objects, the sum of momentum before the collision equals the total momentum after the collision. An elastic collision conserves internal kinetic energy, and so the sum of kinetic energies before the collision equals...
21.0K
01:19Types of Collisions - II
10.4K
When two or more objects collide with each other, they can stick together to form one single composite object (after collision). The total mass of the object after the collision is the sum of the masses of the original objects, and it moves with a velocity dictated by the conservation of momentum. Although the system's total momentum remains constant, the kinetic energy decreases, and thus such a collision is an inelastic collision. Most of the collisions between objects in daily life are...
10.4K
01:05Collisions in Multiple Dimensions: Introduction
7.2K
It is far more common for collisions to occur in two dimensions; that is, the initial velocity vectors are neither parallel nor antiparallel to each other. Let's see what complications arise from this. The first idea is that momentum is a vector. Like all vectors, it can be expressed as a sum of perpendicular components (usually, though not always, an x-component and a y-component, and a z-component if necessary). Thus, when the statement of conservation of momentum is written for a...
7.2K
01:04Types Of Collisions - I
9.7K
When two objects come in direct contact with each other, it is called a collision. During a collision, two or more objects exert forces on each other in a relatively short amount of time. A collision can be categorized as either an elastic or inelastic collision. If two or more objects approach each other, collide and then bounce off, moving away from each other with the same relative speed at which they approached each other, the total kinetic energy of the system is said to be conserved. This...
9.7K
01:06Collisions in Multiple Dimensions: Problem Solving
5.6K
In multiple dimensions, the conservation of momentum applies in each direction independently. Hence, to solve collisions in multiple dimensions, we should write down the momentum conservation in each direction separately. To help understand collisions in multiple dimensions, consider an example.
A small car of mass 1,200 kg traveling east at 60 km/h collides at an intersection with a truck of mass 3,000 kg traveling due north at 40 km/h. The two vehicles are locked together. What is the...
A small car of mass 1,200 kg traveling east at 60 km/h collides at an intersection with a truck of mass 3,000 kg traveling due north at 40 km/h. The two vehicles are locked together. What is the...
5.6K