Glycol modified siloxane

[Caffeinated Chemist]

I have synthesized a glycol modified silane from the starting materials of 1,2-propane diol and methyl trimethoxysilane. The structure of the product can be found below.

 

The process involves removal of methanol by distillation under an inert atmosphere at a high temperature (140 degrees C for 16 hours).

 

My question involves the following. My product smells like old gym socks marinated in rubbing alcohol then left to ferment under a leaking sink for a year. I have made dozens of variations on this compound and none of them smell like this. The 1H and 13C NMR on this compound look clean. Can anyone suggest why my compound smells so terrible?

 

My current theorys include contamination by an oxidized version of the product and/or degradation of the product into an ether. What do you all think?

[Enthalpy]

What if you put a drop, say, on a sheet of paper you place outside, and wait? Maybe most of your material stays and the odour vanishes or diminishes? This would be a first hint that a minor product makes the smell.

[John Cuthber]

Looking at the structure of that molecule I'd expect it to have a very low vapour pressure so I'd be surprised if it smells at all.

[Caffeinated Chemist]

What if you put a drop, say, on a sheet of paper you place outside, and wait? Maybe most of your material stays and the odour vanishes or diminishes? This would be a first hint that a minor product makes the smell.

I might just try that. If it works it might even be worth trying to stir the bulk product in an open container to get rid of the smell. It is seriously like a punch in the face.

 

Looking at the structure of that molecule I'd expect it to have a very low vapour pressure so I'd be surprised if it smells at all.

Agreed. It must be some contaminant.