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The thermally unstable, primary perfluoroalcohols, CF3OH, C2F5OH, and nC3F7OH, were conveniently prepared from the corresponding carbonyl compounds in anhydrous HF solution. Experimental values for the reaction enthalpies and entropies were derived from the temperature dependence of the RfCOF+HF⇄RfCF2OH (Rf=F, CF3, CF3CF2) equilibria by NMR spectroscopy. Electronic structure calculations of the gas‐phase and solution reaction energies, gas‐phase acidities and heats of formation were carried out at the G3MP2 level, showing that these compounds are strong acids. Protonation of these alcohols in HF/SbF5 produced the perfluoroalkyl oxonium salts RfCF2OH2+SbF6−. Highly acidic alcohols: The thermally unstable primary perfluorinated alcohols, CF3OH, C2F5OH, and nC3F7OH, and their oxonium salts were prepared from the corresponding carbonyl compounds in anhydrous HF and superacidic HF/SbF5 solutions. NMR spectroscopy allowed for the determination of experimental energy values obtained from the temperature dependence of the equilibria. Theoretical calculation of energetics, gas‐phase acidities and heats of formation at the G3MP2 level showed the strong acidic nature of these alcohols. [ABSTRACT FROM AUTHOR]

The thermally unstable α-fluoroalcohol undecafluorocyclohexanol (c-C6F11OH) was prepared by addition of hydrogen fluoride to the corresponding ketone. c-C6F10(CF3)OH was obtained by protonation of its alkoxide [NMe4]+[C7F13O]−. Decafluorocyclohexane-1,1-diol (c-C6F10(OH)2) was prepared by acidic workup of the corresponding alkoxide [NMe4]+[C6F11O]− with sulfuric acid, which yielded (c-C6F10(OH)2) and fluorosulfonic acid. The structures of c-C6F10(CF3)OH·2H2O and of (c-C6F10(OH)2) were elucidated by single-crystal X-ray and gas-phase electron-diffraction studies. [ABSTRACT FROM AUTHOR]

Abstract: The first X‐ray crystal structure of an α‐fluoroalcohol is reported. Heptafluorocyclobutanol was obtained in quantitative yield from hexafluorocyclobutanone by HF addition in anhydrous hydrogen fluoride. The compound was characterized by its X‐ray single crystal structure. Heptafluorocyclobutanol readily undergoes hydrolysis to hexafluorocyclobutane‐1,1‐diol, which was also structurally characterized by X‐ray diffraction. [ABSTRACT FROM AUTHOR]

Abstract: The first X‐ray crystal structure of an α‐fluoroalcohol is reported. Heptafluorocyclobutanol was obtained in quantitative yield from hexafluorocyclobutanone by HF addition in anhydrous hydrogen fluoride. The compound was characterized by its X‐ray single crystal structure. Heptafluorocyclobutanol readily undergoes hydrolysis to hexafluorocyclobutane‐1,1‐diol, which was also structurally characterized by X‐ray diffraction. [ABSTRACT FROM AUTHOR]

This study presents the synthesis and characterization of two spirobifluorenyl derivatives substituted with either triphenylmethyl (SB-C) or triphenylsilyl (SB-Si) moieties for use as host materials in phosphorescent organic light-emitting diodes (PHOLED). Both molecules have similar high triplet energies and large energy gaps. Blue Ir(tpz)3 and green Ir(ppy)3 phosphorescent devices were fabricated using these materials as hosts. Surprisingly, SB-Si demonstrated superior charge-transporting ability compared to SB-C, despite having similar energies for their valence orbitals. In particular, SB-Si proved to be a highly effective host for both blue and green devices, resulting in maximum efficiencies of 12.6% for the Ir(tpz)3 device and 9.6% for the Ir(ppy)3 device. These results highlight the benefits of appending the triphenylsilyl moiety onto host materials and underscore the importance of considering the morphology of hosts in the design of efficient PHOLEDs. [ABSTRACT FROM AUTHOR]

Two‐coordinate carbene Cu(Ι) amide complexes with sterically bulky groups such as the diisopropyl phenyl (dipp) on the carbenes have been shown to have comparable performance to the phosphorescent emitters bearing heavy atoms such as iridium and platinum. These bulky groups enforce a coplanar molecular structure and suppress the nonradiative decay rates. Here, three different two‐coordinate Cu(Ι) complexes were investigated that bear a common thiazole carbene, 3‐(2,6‐diisopropylphenyl)‐4,5‐dimethylthiazol‐2‐ylidene, with only a single dipp group, and carbazolyl ligands with substituents of varying steric bulk ortho to N. These substituents have a negligible impact on luminescence energies of the complexes but serve to modulate the rotation barriers along the metal–ligand coordinate bond. The geometric arrangement of ligands (syn‐ or anti‐conformer) in complexes with alkyl substituents were found to differ, being syn in the solid state versus anti in solution as revealed by crystallographic analysis and nuclear magnetic resonance spectroscopy. In addition, calculations were performed to determine potential energy surfaces for different conformations of the three complexes to provide a theoretical evaluation of rotation barriers around the metal–ligand bond axis. The relationship between rotation barriers and photophysical properties demonstrate that rates for nonradiative decay decrease with increasing bulk of the substituents on the carbazolyl ligand. [ABSTRACT FROM AUTHOR]

Invited for the cover of this issue is Karl O. Christe and co‐workers at the University of Southern California, Los Angeles, CA. and The University of Alabama, Tuscaloosa, AL. The image depicts a group of people enjoying alcohol at the Oktoberfest, but this includes a warning that perfluoroalcohols are strong acids, unsuitable for human consumption. Read the full text of the article at 10.1002/chem.201804306. "These alcohols do not have properties usually associated with conventional alcohols but are actually stronger acids than HF and ortho‐phosphoric acid." Read more about the story behind the cover in the Cover Profile and about the research itself on page 16737 ff. (DOI: 10.1002/chem.201804306). [ABSTRACT FROM AUTHOR]

Perfluoroalcohols: Although thermally unstable, these alcohols can be readily accessed through equilibria of the corresponding acyl fluorides with HF in anhydrous HF solution. These equilibria can be shifted to the side of the alcohols by trapping them as oxonium salts, ethers or alkoxides, thus making these reactions synthetically useful. More information can be found in the Communication by K. O. Christe et al. on page 16742. [ABSTRACT FROM AUTHOR]

• Organometallic iridium complexes, (C^N) 2 Ir(BOX), are reported with chiral bis-oxazoline (BOX) ancillary ligands. • (C^N) 2 Ir(BOX) complexes display highly efficient phosphorescence across the visible spectrum. • Δ and Λ diastereomers with cyclometallated phenyl-pyridine ligands, (ppy) 2 Ir(BOX), complex were isolated and characterized. • Diastereomers have identical properties, except for circular dichroism (CD) and circularly polarized emission (CPL) spectra. • An unprecedented match/mismatch effect between ligand chirality and the CPL magnitude is observed in these diastereomers. Organometallic iridium complexes with two cyclometalated ligands (C^N) and one bis-oxazoline derived ancillary ligand (L^X), i.e. (C^N) 2 Ir(L^X), are reported. The C^N ligands are 1-phenylpyrazoline (ppz), 2-(4,6-difluorophenyl)pyridine (F 2 ppy), 2-phenylpyridine (ppy), 1-phenylisoquinoline (piq). The box ligand is (4S-+)-phenyl-α-[(4S)- phenyloxazolidin -2- ylidene ]-2-oxazoline-2-acetonitrile. The emission of these complexes span across the visible and into the near-ultraviolet region of the electromagnetic spectrum with moderate to high photoluminescence quantum yields (Φ PL = 0.45–1.0). These complexes were found to emit from a metal-ligand to ligand charge transfer (ML'LCT) state and have lifetimes (1.3–2.1 μs), radiative rates (105 s−1), and nonradiative rates (104–105 s−1) comparable to state-of-the-art iridium emitters. The (ppy) 2 Ir(BOX-CN) complexes were resolved into the Δ- and Λ- diastereomers using differences in their solubility and additionally characterized by x-ray crystallography, stability, and chiroptic studies. The high Φ PL of these isomers results in the best to date brightness for circularly polarized luminescence (CPL) from iridium complexes (7.0 M−1 cm−1), with dissymmetry factors of −0.57 × 10−3 and +1.9 × 10−3 for 3Δ and 3Λ , respectively. The significant difference in CPL magnitude between 3Δ and 3Λ likely arises from interligand interactions (edge-to-face arrangement versus strong π-π interaction) for the pendant phenyl ring of the BOX-CN ligand which differ for the two isomers. [ABSTRACT FROM AUTHOR]