Reactions of Arylcarbenes with Lewis Acids

  • ChemPubSoc Europe Logo
  • Author: Chemistry – A European Journal
  • Published Date: 18 December 2018
  • Source / Publisher: Chemistry – A European Journal/Wiley-VCH
  • Copyright: Wiley-VCH Verlag GmbH & Co. KGaA
thumbnail image: Reactions of Arylcarbenes with Lewis Acids

Related Societies

Carbenes are important intermediates in many chemical reactions. Their reactivity is governed by their spin states—either singlet or triplet. There is a growing interest in systems capable of controlling the spin state of carbenes by intra- or intermolecular interactions.


Wolfram Sander and colleagues, Ruhr-University Bochum, Germany, have explored the intermolecular reactions of three arylcarbenes which have a triplet ground state with the Lewis acids H2O, ICF3, and BF3 using a matrix isolation technique. The carbenes were generated in their ground spin state at 3 K by photolysis of the corresponding diazo precursor in an argon matrix containing 1 % of the Lewis acid. At 3 K, the diffusion of species isolated in a solid argon matrix is inhibited. Thus, the matrix was annealed at 25–30 K for several minutes to allow the team to monitor the resultant bimolecular interaction by infrared (IR), UV/Vis, and electron paramagnetic resonance (EPR) spectroscopy.


The researchers found that the singlet states of some of the tested carbenes become accessible by interaction with the Lewis acids. The singlet states are much more stabilized by hydrogen bonding, halogen bonding, and Lewis acid–base interactions than the triplet states. The strength of the interaction varies depending on the carbene and the Lewis acid used. For example, the stabilization of singlet carbenes by halogen bonding with ICF3 is larger than the stabilization by hydrogen bonding with H2O.


 

Article Views: 622

Sign in Area

Please sign in below

Additional Sign In options

Please note that to comment on an article you must be registered and logged in.
Registration is for free, you may already be registered to receive, e.g., the newsletter. When you register on this website, please ensure you view our terms and conditions. All comments are subject to moderation.

Article Comments - To add a comment please sign in

Bookmark and Share

If you would like to reuse any content, in print or online, from ChemistryViews.org, please contact us first for permission. more


CONNECT:

ChemistryViews.org on Facebook

ChemistryViews.org on Twitter ChemistryViews.org on YouTube ChemistryViews.org on LinkedIn Sign up for our free newsletter


A product of ChemPubSoc Europe (16 European Chemical Societies)and Wiley-VCH