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Updated: Jun 10, 2026

Isolating Free Carbenes, their Mixed Dimers and Organic Radicals
Published on: April 19, 2019
A carbene-carbene complex equilibrium
Robert A Moss1, Lei Wang, Christina M Odorisio
1Department of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey, New Brunswick, New Jersey 08903, USA. moss@rutchem.rutgers.edu
Abstract:
Phenylchlorocarbene, generated by laser flash photolysis of phenylchlorodiazirine, formed highly stable pi-type complexes with 1,3,5-trimethoxybenzene in pentane. The carbene and carbene complexes were in equilibrium. We measured the equilibrium constant (K = 1264 M(-1) at 294 K) and, from its temperature dependence, extracted the associated thermodynamic parameters: DeltaH(o) = -7.1 kcal/mol, DeltaS(o) = -10.2 eu, and DeltaG(o) = -4.1 kcal/mol. The carbene complexes were characterized by UV-vis spectroscopy and computational analysis.
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