Angular momentum quenching

Optical recording systems, 6, 126 Optical resolution amine metal complexes, 2,25 Oral contraceptives iron deficiency, 6, 764 Orbital angular momentum quenching, 1,262 /-Orbital systems... 

This is known as the spin-only formula. Many ions which in the free state have orbital angular momentum L 0), lose it, completely or partially, when incorporated into a complex. This phenomenon is called orbital angular momentum quenching. It can be shown that for A states the quenching is complete and that for T and E states it is incomplete. Because of this, the spin-only formula applies to more situations than might have been expected. 

Orbital angular momentum quenching, 262 /-Orbital systems... 

Because of the spin-space geminal-space isomorphism found in the simple model, consideration of the behavior of the energies and the wave functions runs along completely parallel tracks in the two cases. This includes the identification of conditions under which the lowest two states are degenerate, of particular interest for photochemistry. Phenomena such as "sudden polarization" and "orbital angular momentum quenching" all fit into a single picture. 

Now take the case for an octahedral vanadium(iii) ion. For d, the ground term is Tig. The spatial degeneracy of a 7 term is three-fold and we describe this with Leff = 1. Using (5.10) we find eff = VlO. So for this Tig term, the crystal field has quenched some, but not all, of the angular momentum of the parent free ion F term. 

This chapter presents a physical description of the interaction of flames with fluids in rotating vessels. It covers the interplay of the flame with viscous boundary layers, secondary flows, vorticity, and angular momentum and focuses on the changes in the flame speed and quenching. There is also a short discussion of issues requiring further studies, in particular Coriolis acceleration effects, which remain a totally unknown territory on the map of flame studies. 

The result of this lower symmetry of the environment is the quenching of the orbital angular momentum of the electron the orbital angular momentum is no longer a good quantum number and has an average value of zero. Some contribution of the orbital motion however remains, and this causes a positive or negative deviation of the g-factor from the free spin value of 2.0023. 

There is an odd electron partially distributed between the dyz and dzx orbitals, which still retain their degeneracy and their rotational properties with respect to the 2-axis. The orbital angular momentum is thus not quenched by the ligand-field, and values of the magnetic moment as high as 4.1 B.M. are possible. The moment should be temperature dependent, and at low temperatures should drop rapidly towards zero, as the lowest state due to spin-orbit coupling is in fact nonmagnetic (74, 75). 

The magnetic moments for solid silver(II) N-heterocyclic complexes are generally close to 1.8 BM suggesting quenched orbital angular momentum and spin-only paramagnetism (Table... 

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