Dear Deepan,

There are a number of factors affecting volatility, and then there are various considerations in evaporation to consider.

Factors affecting volatility:

Overall MW of the allene - the lower the MW the more volatile it's likely to be.

Nature of the allene - side groups will affect MW but also how the molecule interracts with solvent(s) and the other moelcules. The more branched and the more interractive groups you have, the less volatile the molecule - generally.

Factors in Evaporation:

Solvent choice - and how volatile it is compared to the allene. If your solvent is less volatile than your sample ...

Assuming you have a solvent less volatile than your sample, then while it wet, the pressure in the system controls the boiling point and temperature of your sample, so the allene is not so likely to evaporate while in solvent.

The issue with rotary evaporator is that you create a thin film which flash dries - useful for things that are difficult to dry but a headache for volatile samples. careful control of vacuum level (i.e. get the pressure right so you just boil off the solvent) will help, but will make the drying time longer

Alternative, invest if you can, and buy a centrifugal concentrator as these tend to keep the sample in solution until dry, helps here, but can cause a headache with difficult to dry samples.

Kind regards,

Rob