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[Display omitted] 1-Alkylsulfanyl-4-X-2,3,5,6-tetrafluorobenzenes (X = CF 3 , H; alkyl = Me, Bn, CHF 2) upon reactions with nitromethane in the presence of DBU undergo replacement of 2 or 3-positioned fluorine atoms by a nitromethyl group to afford the corresponding (nitromethyl)trifluoroarenes. The calculations of the transition states using the DFT method correctly predict the ratios of reaction products. In the cases of relative sulfones, only 2-positioned fluorine atom undergoes substitution; however, the sulfonyl group can also be displaced by a nitromethyl moiety. [ABSTRACT FROM AUTHOR]

We demonstrate that a series of perfluorinated para-oligophenylenes C6F5-(C6F4)n-C6F5 (n = 1–3) produce exciplexes with N,N-dimethylaniline (DMA) in degassed X-irradiated n-dodecane solutions. The optical characterization of the compounds shows that their short fluorescence lifetimes (ca. 1.2 ns) and UV-Vis absorption spectra, overlapping with the spectrum of DMA with molar absorption coefficients of 2.7–4.6 × 104 M−1cm−1, preclude the standard photochemical exciplex formation pathway via selective optical generation of the local excited state of the donor and its bulk quenching by the acceptor. However, under X-rays, the efficient assembly of such exciplexes proceeds via the recombination of radical ion pairs, which delivers the two partners close to each other and ensures a sufficient energy deposition. The exciplex emission is completely quenched by the equilibration of the solution with air, providing a lower bound of exciplex emission lifetime of ca. 200 ns. The recombination nature of the exciplexes is confirmed by the magnetic field sensitivity of the exciplex emission band inherited from the magnetic field sensitivity from the recombination of spin-correlated radical ion pairs. Exciplex formation in such systems is further supported by DFT calculations. These first exciplexes from fully fluorinated compounds show the largest known red shift of the exciplex emission from the local emission band, suggesting the potential of perfluoro compounds for optimizing optical emitters. [ABSTRACT FROM AUTHOR]

A series of six novel cluster complexes [M6I8(SArf)6]2− (M=Mo or W; SArf=p‐SC6F4‐C6F5, p‐SC6F4Cl, or p‐SC6F4CF3) was prepared by exchange reactions between [Mo6I14]2− or [W6I14]2− and silver salts of the corresponding thiols and characterized by X‐ray single‐crystal diffraction and elemental analysis, NMR, ESI‐MS, and CV techniques. In the crystal structures all the thiolate ligands adopt an idiosyncratic orientation along one of the idealized three‐fold axes passing through two opposite μ3‐I ligands and the centers of two opposite faces of the M6 octahedra. This leads to shortened intramolecular C⋅⋅⋅I distances inside the cluster below 3.5 Å. The clusters exhibit red photoluminescence with relatively high quantum yield, up to 0.42 in the case of (Bu4N)2[W6I8(SC6F4CF3)6]. Moreover, all the compounds exhibit X‐ray luminescence; the close values of the maxima in the photo‐ and X‐ray induced emission spectra indicate that the luminescence is cluster‐centered. [ABSTRACT FROM AUTHOR]

The synthesis of new Pt(II) diimine complexes bearing perfluorinated thiolate ligands, Pt(II)(NN)(4-X-C(6)F(4)-S)(2), where NN = 2,2'-bipyridine or 1,10-phenanthroline and X = F or CN, is reported, together with an investigation of the nature and dynamics of their lowest excited states. A combined UV-vis, (spectro)electrochemical, resonance Raman, and time-resolved infrared (TRIR) study has suggested that the HOMO is mainly composed of thiolate(pi)/S(p)/Pt(d) orbitals and that the LUMO is largely localized on the pi*(diimine) orbital, thus revealing the [charge-transfer-to-diimine] nature of the lowest excited state. An enhancement of the thiolate ring vibrations, C-F vibrations, and the vibration of the CN-substituent on the thiolate moiety was observed in the resonance Raman spectra, whereas no such enhancement was seen for the nonfluorinated analogues. Thus, the introduction of fluorine substituents on the thiolate moiety probably leads to a more pronounced contribution of the intrathiolate modes to the HOMO compared to the analogous complexes with nonfluorinated thiolates. Furthermore, the introduction of the p-CN group into the thiolate moiety has allowed the dynamics of the lowest excited state of Pt(bpy)(4-CN-C(6)F(4)-S)(2) to be monitored by picosecond TRIR spectroscopy. The dynamics of the lowest [charge-transfer-to-diimine] excited state are governed by ca. 2-ps vibrational cooling and 35-ps back electron transfer.