Dear Amravati Singh this is certainly an interesting and somewhat unusual technical question. It is not really clear to me what you mean by a "terrible precursor"? To me, [RhCl(CO)2]2 is a normal organometallic rhodium complex as many others. It is fairly easily accessible through reaction of RhCl3x3H2O with CO under different conditions (see e.g. G. Wilkinson, Inorg. Synth. 1966, 8, 211). The compound forms nice orange-red crystals, so what is "terrible" about it?
For more general information about the use organorhodium complexes as hydroformylation catalysts please have a look at the following useful review article:
Current State of the Art of the Solid Rh-Based Catalyzed Hydroformylation of Short-Chain Olefins
Article Current State of the Art of the Solid Rh-Based Catalyzed Hyd...
The paper has been posted as public full text on RG and can be freely downloaded as pdf file.
Best wishes for your research! 👍
Frank T. Edelmann thank you for your valuable reply sir, actually, this question was raised by the reviewer, that this precursor is terrible for use in hydroformylation. So, I want to know how it is terrible?
Dear Amravati Singh this question raised by the reviewer is very interesting indeed. I assume that the reviewer is right in that [RhCl(CO)2]2 itself is not a very good catalyst for molecular hydroformylation reactions. Quite often, effective catalysts are prepared from [RhCl(CO)2]2 e.g. by reactions with phosphines or other ligands. For a typical reference please have a look at this fairly old article entitled
Diphosphine–Rhodium Complex-Catalyzed Hydroformylation of α,β-Unsaturated Esters
Article Diphosphine–Rhodium Complex-Catalyzed Hydroformylation of α,...
(see attached pdf file)
In this study it was shown that the catalytic activity of [RhCl(CO)2]2 was very low. When chelating diphosphine ligands were added, the hydroformylation reactions became very fast and selective. Thus it may well be that [RhCl(CO)2]2 alone is not a good catalyst for this type of reactions.