Dear Hüseyin gümüş,

It depends on the type or chemical reaction. It depends on the price of your catalyst or reactives.

I don´t know what kind of reaction are you going to do. For example you can maybe work mixing reactives with your catalyst in an autoclave under the adequate inert or reactive gas/es, temperature, pressure, etc. And it can be OK if then you can separate the catalyst well from the products+reactive.

Or you can use your clay-catalyst in a continuous flow reactor but maybe your product is a solid (without solvent) and you can blocke the system.

My only answer is that I need more information from your process.

Regards

What it means solvent-free in your case (details of your reaction)? We have performed enzymatic reactions with excellent enantioselectivity (> 200) in a solvent-free system, by mixing the racemic crytalline substrate with the immobilized enzyme (see Forro and Fulop, Tetrahedron: Asymmetry 2008; 19:1005-1009).The conditions of a reaction are important not only from economical point of view, but nowadays iit is also extremly important to develop environmentally friendly routes to the desired products.

The selection of solvent depends upon the reaction u have chosen.

If both the reactant are in liquid phase and product of the reaction is also in liquid phase the use of solvent is not so effective in such case try to do reactions without solvent

When one of your reactant or product formed is the solid form then its better to use the solvent for well dispersion of catalyst in reaction media

No w days , scientist are looking to avoid the use of solvent bcoz of their high volatility if u do without solvent its best and good if not also its ok there is no much of Problem.

U initially try one reaction with solvent and without solvent and then see which gives you promising result based ion that u further proceed.

While choosing one has too think of its boiling point, dielectric constant , its acceptor number and donor number

Al the best

regards

vijay

To homogenize the medium solvents would be better option.

If you are using the solid catalyst, then you have to consider some of the point below

1. Most of the active sites in the solid catalyst is situated in the bulk. Thus, you need to facilitate the reactants to access the active sites and after the reaction products being formed, you need to transport it out.

2. This the pore opening and surface area of you clay are important.

3. make sure the pore opening is large enough for your reactant penetrate in to access the active sites.

You should not have the fear of the solvent absorbing your catalysts. If the catalyst dissolves in solvent then it only turn the catalysis from heterogeneous to homogeneous.

The solvent need to have low affinity to the active sites, if not the solvent will poison the catalyst.

I

I always try both as I often find solvent-less to give higher yields (see ChemSusChem, 2009, 1025-1027). It is important that you fully describe what you mean by solvent-less as different people have different views (e.g. an esterification whereby the alcohol is in excess and no additional solvent added, is that solvent-less or not?). As a green chemist I always also highlight to people that solvent-less isn't always greener as you will still require solvent for the work-up, and this likely being the greater amount of waste.

Hope that helps,

Tom

I would agree with Tom Farmers answer. Doing a reaction solvent free can be beneficial, although if you then use a load of solvent to recover your product and catalyst, then its not solvent free, and you may be better off using solvent from the start. For clay type catalysts, you may need solvent to open up the layers where many of the sites are to be found, so this may be an additional consideration.

Yes, Agree with Thomas Farmer. You need need to furbish us with more detail of the reaction in order for us to further analyze your situation and made suggestion.

I think you can go for use of CO2 under supercritical condition, if possible.

Solvent-free reaction is advantageous actually otherwise the reaction should be carried out in aqueous medium. This is also preferred.

Solvent-free reaction seems to be better, however, we can not use solvent-free method in all reactions.

Solvent free is really better in ideal situation, because you have less waste to manage, less side reactions, in some cases faster.

Your question is incorrect.

No common answer exists.