Using photoelectron spectroscopy for the investigation of substituent effects in N‐ and P‐centered radical cations

The information concerning the peculiarities of the intramolecular interactions in the radical cations which is currently available is very sketchy. In this work, a new approach to the investigation of the substituent effects in N‐ and P‐centered radical cations has been developed. It is based on a consideration of the core‐electron binding energies E and ionization potentials I of the 15 series of the neutral molecules measured by photoelectron spectroscopy. Properties E and I obey the linear free energy relationship. By using the correlation analysis, in radical cations the inductive, resonance, and polarizability effects were first established to be in operation. The polarizability effect is caused by the charge on the radical cation centers N^?+ and P^?+. The contribution of this effect ranges from 10 to 55%. In the radical cations containing the moieties with N^?+?X and P^?+?X bonds, the standard resonance constants σ_R and σ of the substituents X are of limited utility. An understanding of the substituent effects may give a better insight into the mechanisms of both: radical ions and heterolytic reactions. Copyright © 2010 John Wiley & Sons, Ltd.     

N → C2 → C3 migration of the dichlorophosphino group in the synthesis of phosphorylated NH‐pyrroles

A successive N → C₂ → C₃ migration of the dichlorophosphino group has been found to occur in phosphorylation of unsubstituted pyrrole with phosphorus trichloride. As a result of this migration, a number of hitherto unknown C‐phosphorylated N‐unsubstituted pyrroles have been obtained. © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:671–676, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20495