43 / 2023-08-13 17:53:19

3a,6a-Diaza-1,4-diphosphapentalenes : a new class of organophosphorus π - donors

Diazadiphosphapentalenes; charge transfer complexes, tetracyanobenzene

New Technologies in Phosphorus Chemistry > 1) New reagents and methods in organophosphorus Chemistry

Diazadiphosphapentalenes (DDP) are a young class of organophosphorus heterocycles, showing the dualism of chemical properties due to an unusual electronic structure. On the one hand, they are able to form a structure similar to singlet phosphinidenes, on the other hand, they demonstrate formation of a 10πе aromatic system¹ (Fig. 1) :Diazadiphosphapentalenes (DDP) are a young class of organophosphorus heterocycles, showing the dualism of chemical properties due to an unusual electronic structure. On the one hand, they are able to form a structure similar to singlet phosphinidenes, on the other hand, they demonstrate formation of a 10πе aromatic system¹ (Fig. 1) . 



High π – donor ability of DDP allows carrying out reactions with organic acceptors, particularly with tetracyanobenzene (TCNB)². This work discusses the synthesis of complexes of 1,2,4,5-tetracyanobenzene with new diazadiphosphapentalenes containing alkyl and aromatic  substituents (I – V) in the peripheral environment (Fig.2).



According to the CV data, the new diazadiphosphapentalenes are strong electron donors showing oxidation peak potentials (0.1 – 0.5 V vs Ag/AgCl). Synthesized complexes have well-defined stoichiometry and contain molecular chains that form donor and acceptor layers.