Cross-conjugated enediynes cannot follow the Bergman cycloaromatization as it involves a methylenediyne moiety with only five pi e(-), insufficient for aromatization. Under reductive conditions the cyclization is made feasible by generating a product with a Hückel number of pi electrons. We illustrate this principle and demonstrate for the first time an anionic cyclization of a cross-conjugated...

Since the pioneering works on the first double-layer thin-film Organic electroluminescence (EL) devices (OLEDs) by C. W. Tang and co-workers in the Kodak Company in 1987 (Tang  Vanslyke, 1987), OLEDs have attracted enormous attentions in the scientific community due to their high technological potential toward the next generation of full-color-flat-panel displays (Hung  Chen, 2002; Wu et al.,...

The title compound, C(29)H(24)Cl(2)O(2), a fluorene derivative, features a C atom that is connected to four phenyl-ene rings, two of which are almost coplanar (r.m.s. deviation = 0.035 Å) as they belong to the fluorene system. The other two rings are aligned at angles of 67.5 (5) and 85.5 (5)° with respect to the pair. The O and Cl atoms of the -OCH(2)CH(2)Cl- units adopt a gauche conformation ...

The present paper considers the possibility to obtain a magnetic ordering of the proton spins in molecular crystals of fluorene using dynamic nuclear polarization (DNP) followed by adibatic demagnetization in the rotating frame (ADRF). It is found that such an ordering is most easily reached for T < 0 and 80 II c-axis. Then a polarization of only 26% needs to be reached by DNP in order to obtai...

In this work a lipopeptide biosurfactant, obtained from an agro industrial residue, was used as washing agent to remove fluorene from soil. Soil extraction carried out with biosurfactants is more environmental friendly tan those extraction based on volatile solvents or chemical surfactants. Thus, in order to find the best operational conditions, the effect of soil loading and pH during batch so...

In the title compound, C(20)H(15)N, the fluorene unit is essentially planar [r.m.s. deviation 0.0334 Å] and the benzene ring bound to the imine N atom bears a methyl group which is nearly coplanar [dihedral angle 0.5 (1)°]. The dihedral angle between the substituent benzene ring and the 9H-fluoren-9-imine unit is 71.1 (3)°. Inter-molecular π-π inter-actions between the benzene rings of adjacent...

The stereodynamic processes and conformational preferences of two classes of aryl fluorenyl ketones have been investigated by means of dynamic NMR spectroscopy, DFT calculations and X-ray diffraction. When the aryl substituent has two hydrogens in the ortho positions, its rotation is independent of that of the fluorene ring. In contrast, if the two ortho hydrogens are replaced by the bulkier me...

Oxidation of m- and p-substituted benzylidene fluorenes to antiaromatic dications was attempted by electrochemical and chemical means. Electrochemical oxidation to dications was successful for benzylidene fluorenes with p-methoxy, p-methyl, p-fluoro, and unsubstituted phenyl rings in the 3-position; attempts to oxidize the m-substituted derivatives via electrochemistry were unsuccessful. Chemic...