The chemistry of fluorine containing phosphaalkenes, arsaalkenes and selenocarbonyls

1,4-Bis(trifluoromethyl)benzene as a new acceptor for the design and synthesis of emitters exhibiting efficient thermally activated delayed fluorescence and electroluminescence: experimental and computational guidance

“…A closer inspection indicates that the Sigma-bond of C–F is hyperconjugated with the π bonds of the benzene rings while the lone pairs of fluorine atoms interact with the hyperconjugated carbon, resulting in resonance/electron delocalization that extends from the benzene π-electrons to the fluorine lone pair of electrons. 25,26…”

“…A closer inspection indicates that the Sigma-bond of C-F is hyperconjugated with the p bonds of the benzene rings while the lone pairs of fluorine atoms interact with the hyperconjugated carbon, resulting in resonance/electron delocalization that extends from the benzene pelectrons to the fluorine lone pair of electrons. 25,26 The HOMO energies of 2PO-2CF 3 Ph, 2PS-2CF 3 Ph, and 2AC-2CF 3 Ph were found to be 5.84 eV, À6.04 eV, and À6.06 eV, respectively, while the LUMO energies were À1.76 eV, À1.53 eV and À1.53 eV, respectively. The HOMO and LUMO of 2PO-2CF 3 Ph are deeper than those of the other compounds studied since the oxygen atom in PO enhances the pull-push electron effect of 2PO-2CF 3 Ph.…”

“…It is expected that these lone pairs of electrons can participate in pconjugation and hence increase the extent of electron delocalization of the acceptor. 25,26 The electron-accepting and red-shifting abilities are beneficial for obtaining a small singlet-triplet splitting and promoting reverse intersystem crossing. Highly efficient TADF was observed for molecules containing acceptors with abilities to form intramolecular C-HÁ Á ÁF hydrogen bonds.…”

Phosphines and Related Tervalent Phosphorus Systems

“…653 The chemistry of fluorine-containg phospha-and arsa-alkenes has also been reviewed. 654 Among new contributions from the theoretical chemistry community are a quantum chemical study and vibrational analysis of compounds containing carbon-phosphorus multiple bonds, 655 an investigation of one-bond phosphorus-phosphorus indirect nuclear spin-spin coupling tensors using density functional theory, 656 and estimates of the E¼C s-and p-bond energies for E¼C, Si, Ge and P. 657 Density functional theory has been applied to gain an understanding of the gas-phase formation of the p p -bonded, neutral hexaphosphorus species P 6 , from Cp* 2 P 6 . 658 The use of bulky groups for the kinetic stabilisation of diphosphenes and phosphaalkenes has seen further development, examples of new stable systems including the metacyclophanes (216), 659 the diphosphenes (217), 660 (218), 661 (219), 662 (220) 663 and (221), together with related phosphaalkenes.…”

Facile synthesis of luminescent benzo-1,2-dihydrophosphinines from a phosphaalkene

“…The reaction between phosphaalkenes and alkynes has not been well studied: most examples reported in the literature concern the reactivity of specialized phosphaalkenes and electron rich alkynes, for example the addition of electron rich alkynes to metallophosphaalkenes, 8 phosphoranes, 9 metal-coordinated phosphaalkenes, 10 1,2-thiaphospholes, 11 or fluorinated phosphaalkenes (Scheme 2) 12 has been examined. We were interested in studying the reactivity of a prototypical organo-substituted phosphaalkene with a range of terminal alkynes.…”