Fluorenone

About: Fluorenone is a research topic. Over the lifetime, 1067 publications have been published within this topic receiving 17162 citations. The topic is also known as: Diphenylene ketone & 9-Oxofluorene.

Zur Bildung von Xylol-tricarbonylchrom (Dimethylbenchrotrenen) aus Di-n-butylether und Hexacarbonylchrom

Abstract: The reaction of fluorenone ethyleneketal (9), diphenic anhydride as well as of biphenyls such as4 with Cr(CO)6 in refluxing di-n-butylether (BE) gives dimethylbenchrotrenes [xylene-Cr(CO)3,7] which are also formed by refluxing pureBE with Cr(CO)6—although with much lower yields. Similarily, from di-n-pentylether and Cr(CO)6 isobutyl- and 1-methyl-3-propyl-benchrotrene (13 and14) were obtained, whilst from di-n-propyl- and-hexylether, resp., and Cr(CO)6 no benchrotrenes could be isolated.

Synthesis of 2,7-Fluorenone Bisglycidyl Ether and related compounds as potential cytostatics

Abstract: The syntheses of fluorenone derivatives having one to three glycidyl groups and related compounds are reported. Their activity against experimental tumors in vitro in relation to the molecular structure is discussed.

Fluorenone imidazolium salts as novel de Vries materials

Abstract: In ionic liquid crystals (ILCs) tilted mesophases such as SmC required for electro-optic devices are quite rare. We report a design concept that induced the SmC phase and enabled de Vries-like behaviour in ILCs. For this purpose, we synthesized and characterized a library of ILC derivatives ImR(On,Ym)X which consist of a rigid central fluorenone core containing an alkoxy or thioether side chain and connected via a flexible spacer to an imidazolium head group. The mesomorphic properties were studied by differential scanning calorimetry (DSC), polarizing optical microscopy (POM) and X-ray diffraction (XRD). Temperature-dependent measurements of smectic layer spacing d by small-angle X-ray scattering (SAXS) and of optical tilt angles by POM demonstrate that ILCs ImR(On,Ym)X undergo SmA–SmC phase transitions with maximum layer contraction values between 0.4% and 2.1%. The lowest reduction factor R of 0.2 at the reduced temperature T − TAC = −10 K was calculated for Im(O12,S14)Br. Electron density calculations indicated a bilayer structure. Furthermore, temperature dependent emission studies show that self-assembling has a strong influence on the emission intensity of these ILCs.

Proton nuclear magnetic resonance studies of protonated cyclopentadithiophenones and cyclopentadithiophens

Abstract: The 1H n.m.r. spectra of protonated fluorenone, cyclopentadithiophenones (FSO3H–SbF5–SO2 at –60°), and cyclopentadithiophens (CF3CO2H at –15°) are discussed. Di- and mono (carbonyl)-protonation occurred. Cyclopenta[1, 2-c : 3, 4-c′]dithiophen-7-one and fluorenone are found to be protonated first at the carbonyl group. PPP Calculations show that carbonyl protonated ketones having a cyclopentadiene carbocyclic ring are energetically less favourable than those having a cyclopentane or cyclopentene carbocyclic ring. From the values of the chemical shift of the OH protons it is concluded that the C–O bond remains largely a double bond. Three cyclopentadithiophens are easily protonated in CF3CO2H at –15° at corresponding positions in the b-annulated thiophen ring. The absorption frequencies in the electronic absorption spectra of these protonated cyclopentadithiophens are in good agreement with transition energies calculated by PPP methods.