Structural Variability of R2C Adducts of 3a,6a‐Diaza‐1,4‐diphosphapentalene: Tuning the N→P Bonding |
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| Authors: | Alexander N Kornev Vadim E Galperin Yulia S Panova Alla V Arapova Evgenii V Baranov Georgy K Fukin Gleb A Abakumov |
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| Affiliation: | G. A. Razuvaev Institute of Organometalic Chemistry, Russian Academy of Sciences, Nizhny Novgorod, Russia |
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| Abstract: | 3a,6a‐Diaza‐1,4‐diphosphapentalene (DDP) reacts with hexachlorocyclopentadiene to form a stable adduct (ClC)4C=DDP ( 4 ). The phosphorus atom involved into coordination has a pyramidal arrangement but retains partial double bonding with carbon 1.752(3) Å]. At the same time, the P–N bond remains covalent 1.824(3) Å]. The adduct 4 is better described as a zwitterionic compound with strongly delocalized positive and negative charges. A similar zwitterionic adduct DDP=C(CN)2 was prepared by the reactions of dichloro‐DDP ( 7 ) with malononitrile in the presence of Et3N. DFT calculations showed that related structures are formed in the case of the substituents (ClC)4C=, (HC)4C=, (NC)2C=, and (MeCO)2C=, possessing electron‐delocalizing properties. Compounds with other R2C groups (R = Ph, Me, C6F5, Cl), possessing electronegative properties as well, but insufficient e‐delocalization, demonstrate the noncovalent P–N bonding and a little shorter R2C–P bond lengths (ca. 1.70 Å). |
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| Keywords: | Azaphospholes Phosphorus ylides Hypervalent phosphorus X‐ray diffraction Addition reaction |
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