Pd(dppf)Cl2-CH2Cl2 and Pd(PPh3)4 what is differance between these palladium bases and which one where can i use any specific rule are there or not?
It's a general difference between Pd(2) and Pd(0) catalists; depends on the reaction type you plan to use in...
You may get information from this article
DOI: 10.1021/ar300014f
Before you take up any catalytic work, first read about two important reactions: i) what is Oxidative addition and ii) what is Reductive elimination, and their importance in catalysis and how these two properties are related with respect to the activation of bonds to begin with and then coupling of two entities to form products.
While reading about these aspects, try to understand the influence of: i) nature of the metal atom or ion, ii) its oxidation state(s), iii) coordination number, iv) electronic configuration, v) what is coordinative saturation, vi) role of a base in the activation of a catalyst to generate an active catalytic species, vii) nature of C-Cl, C-Br and C-I bonds and relative bond strengths viii) types of oxidative additions, ix) electron count /18 electron rule, x) importance of 18 e rule in catalysis, xi) stability of a metal complex, xii) the role of thermodynamics in identifying a good catalyst, xiii) microscopic reversibility, the list continues. After understanding these terms, try to compare those two palladium species you have. You will get the answer.
Balakrishna
As far as I know it doesnt matter: they are the same palladium source with same ligands.
Ravindra,
you can clearly see from the very different answers that you need to ask more specifically!
Especially, what do you mean by "i need clearfines on DCM or without DCM"?
Dear R. Kashinath,
Pd(dppf)Cl2-CH2Cl2 and Pd(PPh3)4 are the familiar palladium catalysts which differ in the oxidation state of metal. Not all the times, but most of the times, the C-C bond formations are particular depending on the substrate sensitivity and requires a specific catalyst. Pd(dppf)Cl2-CH2Cl2 is a DCM complex which is comparatively stable and efficient catalyst for many C-C bond formation reactions.
Please, dear colleagues use the correct description for this compound, it should be:
[Pd(dppf)Cl2].CH2Cl2. Dichloromethane is co-crystallised with the complex [Pd(dppf)Cl2]. Co-crystallisates are indicated by a dot, the complex entity by [ ].
Concerning catalysis: the CH2Cl2 is not bound to Pd(II) and it basically does not play any role in catalysis using this catalyst. After dissolving the complex, the CH2Cl2 will be a solvent molecule amongst other solvent molecules.
I can only think about the reaction of CH2Cl2 with a Pd(0) species (intermediate) in an oxidative addition yielding a [Cl-Pd-CH2Cl] species.
This could e.g. happen when you try this catalyst in a Kumada coupling. The Grignard reagent might react with CH2Cl2 in a Wurtz-type of reaction.
To avoid CH2Cl2 you can dissolve the commercially available [Pd(dppf)Cl2].CH2Cl2 in acetone and then pump away any volatiles under reduced pressure. This should yield an non-crystalline material with the composition [Pd(dppf)Cl2].
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