Influence of N-heterocyclic carbenes (NHCs) on the hydrolysis of a diphosphene. Issue 4 (8th January 2020)

• Record Type: Journal Article
• Authors: Dhara, Debabrata; Das, Shubhajit; Kalita, Pankaj; Maiti, Avijit; Pati, Swapan K.; Scheschkewitz, David; Chandrasekhar, Vadapalli; Jana, Anukul
• Is Part Of: Dalton transactions. Volume 49:Issue 4(2019)
• Page Start: 993
• Page End: 997
• Publication Date: 2020-01-08
• Subjects: Chemistry, Inorganic -- Periodicals; Chemistry, Physical and theoretical -- Periodicals; Chemistry, Inorganic -- Periodicals; 546.05
• DOI: 10.1039/c9dt04690a
• Languages: English
• ISSNs: 1477-9226

Abstract

Abstract : Irrespective of reversible coordination or non-coordination of NHC to the diphosphene; the presence of it in a stoichiometric or even in catalytic leads to the hydrolysis of diphosphene. Abstract : We report the influence of N-heterocyclic carbenes (NHCs) on the hydrolysis of a diphosphene TerPPTer (1 ; Ter = 2, 6-Mes2 C6 H3 ; Mes = 2, 4, 6-Me3 C6 H2 ), a phosphorus-analogue of an alkene. The diphosphene 1 itself is completely inert towards water. However, NHCs have been found to activate 1 towards ready hydrolysis. While sterically less-encumbered NHCs react with 1 affording NHC-adducts which are in equilibrium with 1 in solution, sterically encumbered NHCs do not bind to 1 at all. Interestingly, in both of these situations hydrolysis of the PP motif proceeds efficiently. At low temperatures, sterically less-encumbered NHCs are catalytic while the sterically encumbered NHCs play a catalytic role at room temperature. To gain insight on this striking influence of NHCs on the hydrolysis of diphosphene detailed low-temperature 31 P-NMR studies along with theoretical calculations have been carried out. In addition, systematic hydrolysis studies of all the NHCs used in this study have also been performed.