Reactions Of Complexes 15 Flashcards
Associative or dissociative mechanism kis basis pr kahe gye hai
Jab intermediate ka CN. Increase Hota Hai to us mechanism ko associative Kahte hai aur jab decrease Hota Hai to dissociative Kahne hai
Explain steps of dissociative mechanism
- Removal of ligand and form intermediate of low CN.
2, addition of ligand
Geometry of intermediate in dissociative mechanism
CN. Is 5 so geometry could be TBP,Square pyramidal
But mostly square pyramidal
Dissociative mechanism favoured by
High CN. Complexes like octahedral complexes
Rate of dissociative mechanism
Rate = depends on substrate
So order of rxn is 1
SN1 limiting rxn
Associative mechanism steps
Addition of ligand to substrate forming intermediate of high CN.
Removal of ligand
The geometry of intermediate in associative mechanism
TBP
Rate of associative mechanism
Substrate as well as incoming ligand
Order is 2
SN2 limiting
Steps of interchange mechanism
Single step rxn like SN2
No intermediate formation only TS. Formation
Types of interchange meachanism
Two
IA,ld
Factors affecting rate of dissociative mechanism dissociative mechanism
Rate inversely proportional to the metal and leaving group bond strength
So ,it depends on Zeff of metal ,HSAB ,JTD
CFSE,TRANS EFFECT ………..(STERIC EFFECT)
In dissociative mechanism and associative rate relation with the pı donates ligamdd
- Directly proportional
- Inversely proportional….dirctlyproportional with pi accepted ligand
Dissociative and associative relation with steric crowding
- Directly proportional
2.inversly proportional
In non transition metal how can we determine the rate of reaction
For non transition metal rate is inversely proportional to zeff [ OS, size ]
For transition metal complex how can we determine labilenes
1, high JTD
2. Low CFSE
3. Weak MX bond