When we tried to prepare P(CL-co-MBL) copolymer by coordination−insertion ring-opening copolymerization of α-methylene-γ-butyrolactone (MBL) and ε-caprolactone (ε-CL) by using Tris[N,N bis(trimethylsilyl)amide]lanthanum(III) [La(N(Si(CH3)3)2)3] catalyst in toluene we had a problem in dissolving this catalyst in toluene even by using ultrasonic or by warming the catalyst however we have just purchased this catalyst .
So, I will be thankful if you told me how you dissolved this catalyst in toluene.
Dear Islam,
thank you for sharing this very interesting technical question with the RG community. We have more than 30 years of experience in organolanthanide chemistry. During that time we also frequently worked with the silylamide derivatives Ln[N(SiMe3)2]3. The main problem with these compounds is that they are very sensitive to air and particularly to moisture. Thus they must always be handled under nitrogen or argon using a Schlenk line or in a dry-box. Once you open a bottle in air you will have immediate decomposition and hydrolysis. Another problem is that even commercially available samples can already be partially hydrolyzed.
The best way to purify these compounds and make them completely soluble in toluene is vacuum sublimation. For this you need a good vacuum and temperatures around 200 °C. Alternatively you can try to extract the compound with hot toluene, filter under N2 or argon and evaporate the toluene extract to dryness.
Good luck and best wishes, Frank Edelmann
- Badges
- Science topic
- Similar topics
- Philosophy
- Esthetics
- Interpretation