87969-92-4

Upstream product

• 52719-91-2 bis(2,4,6-trimethylphenyl)methyl chloride 
• 21127-91-3 Bis-(2,4,6-trimethyl-phenyl)-methanol 
• 67-56-1 methanol 
• 61080-14-6 dimesityl diazomethane 
• 409322-39-0 N-Nitroso-dimesityl-ketimin 
• 49633-78-5 2,4,6,2',4',6'-hexamethylbenzophenoneimine 
• 74-88-4 methyl iodide 
• 55394-82-6 acetic acid-(2,4,6,2',4',6'-hexamethyl-benzhydryl ester) 

Relevant academic research and scientific papers

Conformational studies by dynamic NMR. 83.1 Correlated enantiomerization pathways for the stereolabile propeller antipodes of dimesityl substituted ethanol and ethers

Below -100 °c, the Nmr spectra of dimesityl derivatives of ethanol and of various ethers reveal how these molecules exist asM and P propeller-like stereolabile enantiomers, owing to the restricted rotation about the Ar-C bond. Single-crystal X-ray diffraction of one such derivative confirmed the existence of a two-blade propeller structure. Computer analysis of the NMR line shape allowed the barriers for the enantiomerization process to be determined. Theoretical modeling (Molecular Mechanics) of the interconversion circuit produced good agreement between the computed and experimental barrier for a correlated dynamic process where a disrotatory one-ring flip pathway reverses the helicity of the conformational enantiomers. Introduction of a configurationally stable chiral center allowed two distinct NMR spectra to be detected at appropriate low temperature for two stereolabile diastereoisomers.

Polymethylated and poly(tert)butylated diphenylcarbenes. Generation, reactions, kinetics, and deuterium isotope effects of sterically congested triplet carbenes

Dimesitylcarbene (2a) was shown to decay by undergoing dimerization and to have a half-life of 160 ms, some 5 orders of magnitude longer-lived than diphenylcarbene. Didurylcarbene (2b) was twice as long-lived as 2a, while decamethyldiphenylcarbene (2c) de

Singlet and Triplet Dimesitylcarbene

The triplet states of essentially all diarylcarbenes react with substrates such as methanol or their parent diazo compounds both of which are thought to be specific quenchers for the singlet state.To rationalize these results, investigators have proposed that the singlet and triplet states of these carbenes are linked by efficient equilibria.In this kinetic study we have found that the singlet and triplet states of dimesitylcarbene exhibit quite distinct chemistries.The singlet state alone reacts with methanol, 1-propanol, and 1,3-cyclohexadiene, while the triplet carbene dimerizes to give olefin or, for example, reacts with oxygen.No evidence was found for reaction of the triplet carbene via the singlet manifold.Arguments are presented to explain the enhanced free energy difference between the spin states of this carbene and the relative persistence if its triplet.

Dimesitylcarbene: The Distinct Chemistries of its Singlet and Triplet States

Dimesitylcarbene is unique amongst the diarylcarbenes thus far investigated since its triplet state cannot readily convert into the singlet state.