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N ‐Heterocyclic Vinylidene‐Stabilized Phosphorus Biradicaloid
Author(s) -
Rottschäfer Dennis,
Neumann Beate,
Stammler HansGeorg,
Ghadwal Rajendra S.
Publication year - 2017
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201702433
Subject(s) - chemistry , ring (chemistry) , singlet state , diamagnetism , crystallography , medicinal chemistry , stereochemistry , organic chemistry , physics , quantum mechanics , magnetic field , nuclear physics , excited state
Abstract Four‐membered biradicaloid compounds containing a N 2 E 2 (E=main group element) framework have been thoroughly investigated; however, the synthesis of stable analogues with a C 2 P 2 skeleton remains a challenge. Base‐mediated double C−H functionalization of IPr=CH 2 ( 1 ) (IPr=C[N(2,6‐ i Pr 2 ‐C 6 H 3 )CH] 2 ) with PCl 3 affords [{(IPr)CP} 2 Cl]Cl ( 2 ) as a royal blue solid. Treatment of 2 with KC 8 yields the stable phosphorus biradicaloid [(IPr)CP] 2 ( 3 ) featuring a four‐membered C 2 P 2 ring. Compound 3 is diamagnetic and shows sharp and temperature‐independent NMR resonances, revealing its singlet biradicaloid nature. The stability of 3 is attributed to the σ‐ and π‐electron‐donating property of the N ‐heterocyclic vinylidene [(IPr)C] group.