Synthesis, structure and π-delocalization of a phosphaalkenyl based neutral PNP-pincer

Preparation, characterization and structural properties of a novel bis-phosphaalkenyl based PNP-pincer are reported. In this pincer the p-system is delocalized over all three donor sites, which was demonstrated with DFT calculations, UV-Vis measurements and structural findings. As a consequence of this extended delocalization the p-system reveals near coplanarity which is evident from the first crystal structure for an uncomplexed bisphosphaalkenyl PNP-pincer. (C) 2011 Elsevier B.V. All rights reserved.