Please don't tell me what the ligand field is. I mean: what means "Dg" literally? It must be an abbreviation, but of which expression?
Vielen Dank, diese Fußnote hatte ich bisher übersehen. Aber heißt das, dass die Variable D mit dem Index q einfach so benannt wurde (sie könnte auch G mit dem Index l heißen) oder gibt es einen Hintergrund für die Bennenung?
In English: thanks for the refence (Huheey, Keiter, Keiter). Thus the variable D has been chosen together with the index q during the mathematical treatment of the electrostatic ligand-field bonding model. Therefore, the letters D and q do not "mean" anything?
Ich bin mir nicht sicher aber q könnte mit der Ladung zusammenhängen und D ist möglicherweise als griechisches Delta zu verstehen. Im Hollemann Wiberg (101. Auflage, S 1250) gibt es eine ganze Reihe Fußnoten mit Originalliteratur. Möglicherweise wird darin näher beschrieben für was D und q steht.
Ja wahrscheinlich, aber dazu habe ich keine große Lust ;-) Daher dachte ich, ich frag mal. Aber vielen Dank nochmal!
D means deci(ten) q means quanta the energy The energy difference between the set of orbitals is deciquanta means 10 quantum of energy
Hi Rejimon, that sound very plausible, THANK you. Where did you learn this?
best
AXEL
The term Dq is the product of two terms D and q and is called Differential of quanta
implying the energy. The word D has been coined from D State (L=2 ) .
D=35ze/4a5----- ----------- (a).
q= 2er4/105. ----------------- (b).
Dq= (1/6) (zer24-/a5) ------- (c).
This factor (Dq) is actually the minimum value of ∫ (±2)*V oct (±2) d t and the values the other d wave functions are the multiples of this quantity [t should be read as tau].
Here a4 – represents mean fourth power radius of d electrons of the central metal ion (Note that 4- should be read as dash on 4).
[This value was arrived as follows: Knowing values of d wave functions (Introduction to Ligand Field Theory By B.N.Figgis: Chap-2), we construct a secular determinant for calculating the effect of Voct (which results in the splitting of five d orbital on the formation of octahedral complex), on the d orbitals by putting the values of Dq (c).]
The potential Voct, may be converted into:
Voct =D(x4+y4+z4-3r4/5) ------------ (d).
by employing the expressions relating spherical polar to Cartesian coordinates
with D and q values equal to (a, b) with product being equal to (c).
you can find your answer from link given below..
http://en.citizendium.org/wiki/Crystal_field_theory
Dear Axel, one of my students ask me this question in a lecture, and embarrassingly I was not able to give a good answer, so I also tried to find out, without trying to go into to much research. I attach two papers and a link (in german) that may (or may not) hint at the origin of the term. Basically it appears that Dq derives for quantum mechanic description of the electrostatic model of crystalline fields and is connected to the radial electron density of the d-electrons, the charge of the metal and the distance of ligands and metal.
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