Doubt from coordination compounds

#1

In the first one, NH3 is a strong ligand so light of lower wavelength (like violet) will be absorbed as the energy gap would be high and the complementary colour will be emitted (can’t find the right word)... in case of violet that would be yellow.

How is the colour blue?

#2

Please help

#3
#4

Again my usual question. But why?

I understood the explanation.

#5

In general NH3 is a SFL but with Fe+2 Mn+2 and Co+2 it will be a wFL

#6

Exactly but why?

#7

Sorry bro . Don't know the reason.. we were told that to do ratta as they are exceptions..

#8

Oh okay no worries. Ratta for inorganic is the way to go.

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#9

Colour of ligand does not depend only on the strength of ligand, even I used to think like that before. You can google the actual reasons, but it's not in syllabus.

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#10

We were told the same that some ligands are weak but behave as strong (and vice versa) with certain oxidation states of certain metals. No reason was given, when asked.

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#12

Bro,you just understand the concept of strong field and weak field ligand by using Crystal field theory.
Also,all these exception likeNH3 is a SFL but with Fe+2 Mn+2 and Co+2 it will be a WFL,are also be done with the help of CFT.