Pyrazolium-sulfonates. Mesomeric betaines possessing iminium-sulfonate partial structures

作者：Dreger Andrij; Muenster Niels; Nieto Ortega Belen; Javier Ramirez Francisco; Gjikaj Mimoza; Schmidt Andreas^*

来源：ARKIVOC, 2012, 20-37.

• N-Heterocyclic carbene
• IR spectroscopy
• pyrazol-3-ylidene
• pyrazol-4-ylidene
• SO3 adducts

Pyrazolium-3-sulfonates and pyrazolium-4-sulfonates possessing the iminiomethanesulfonate and the 3-iminio-pro-1-ene-2-sulfonate partial structure are prepared. Formally, they represent sulfur analogs of cross-conjugated (CCMB) and pseudo-cross-conjugated heterocyclic mesomeric betaines (PCCMB) and sulfur trioxide adducts of abnormal N-heterocyclic carbenes (aNHC) and N-heterocyclic carbenes (NHC), respectively. The theoretical as well as experimental vibrational spectra of these two classes are compared. Results of calculations of HOMO/LUMO profiles and an X-ray single crystal structure analysis are presented.

• 出版日期2012