Amination of pentafluoropyridine, 2,3,5,6 tetrafluoropyridine, 4 chlorotetrafluoropyridine, 3,5 dichlorotrifluoropyridine, octafluorotoluene, α,α,α,2,3,5,6 heptafluorotoluene, deca fluoro m xylene, decafluorobiphenyl, hexafluorobenzene, and pentafluorobenzene with liquid ammonia was investigated. Bis aminodefluorination temperatures for the majority of sub strates were shown to exceed significantly the corresponding temperatures of monoamino defluorination. The optimal conditions for selective preparation of mono and diamino polyfluoro(het)arenes were elucidated. An efficient method for isolation of particular polyfluorophenylenediamines from product mixtures formed in nonselective reactions of pentafluorobenzene and hexafluorobenzene with aqueous ammonia based on complexation with a crown ether is proposed. N. N. Vorozhtsov´s school made a considerable con tribution to the chemistry of polyfluoroaromatic com pounds: methods for the synthesis 1 and functionali zation 2,3a of base polyfluoroarenes were developed. Cur rently many polyfluoroarene derivatives are demanded for high tech processes and materials. In particular, diamino and dihydroxy(poly)fluoroarenes serve as struc tural blocks in the synthesis of polyimides used in fiber optic and thin film light guides, nanofilters, and mem branes, dielectric coatings, liquid crystalline displays, op tical diodes, laser media, etc. 4 Polyfluorinated amines of the benzene and pyridine series are used in the synthesis of biologically active compounds. 5It is known 6 that aminodehalogenation of arenes in aqueous ammonia, which is usually carried out in steel autoclaves at high temperatures (up to 250 °C), is often accompanied by competing transformations of arenes such as hydroxy and/or hydrodehalogenation involving water and the autoclave material. The version of the method of polyfluoroarene amination developed in this study im plies the use of liquid ammonia as both the reagent and the reaction medium. The possibility of aminodefluorina tion of some polyfluoroarenes with enhanced electrophi licity in liquid ammonia has been demonstrated previ ously. 7 The efficiency of liquid ammonia as a medium for aromatic nucleophilic substitution has been described in a review. 8 Note that the temperatures suitable for the work with liquid ammonia are limited by the range from -70 to 120 °C (m.p. -78 °C, critical point 133 °C). 9 It follows from analysis of published data that arene amino dehalogenation in liquid ammonia has a higher rate than that in aqueous ammonia; therefore, the processes are carried out at relatively low temperatures and the side reactions are minimized.The purpose of this study was to elucidate the condi tions for mono and diamination of polyfluorinated ben zene and pyridine derivatives in liquid ammonia, which are optimal as regards the selectivity and product yield, to develop simple and practically feasible techniques for separation of mixtures of amino compounds, and to syn thesize new high purity polyfluoroaromatic diamines de manded in high tech applic...

The reduction of Bcyanonnthracene by two equivalents of potassium in liquid ammonia was shown to yield the 9cyanoanthracene dianion, whereas 1-naphtho-and benzonitrile gave the cyanodihydroaryl anions corresponding to the protonation of nitrile dianions at a position para to the cyano group. The 9-cyanoanthracene dianion underwent the same transformation in the presence of a stronger protonating agent, methanol. According to I3C NMR spectral data of the generated species, the cyano group extracts the negative charge from the *-electronic system: ca 0.20:0*25 e in the case of the 9-cyanoanthracene dianion and ca 0-140.17 e in the case of cyanodihydroaryl anions. These estimations and the general NMR pattern of r-charge distribution in all the anionic species under investigation are in accordance with data from quantum molecular orbital calculations at the PM3 and INDO levels, being reflected by the fairly good linear relationships between the changes of ring carbon chemical shifts on going to the anionic species from the respective neutral precursors on the one hand and the calculated nsharges on the other. The para-orienting effect of the cyano group in the protonation of nitrile dinnions is discussed in terms of the r-charge distribution in the starting dianion and the tendency to form a most stable cyanodihydroaryl anion isomer. RESULTSThe reduction was performed just before recording NMR spectra by adding two equivalents of potassium 'Part5 of the series 'Reductive Alkylation of Arenes.' For Parts 1-4, see Refs 1 and 2. t Present address:

Rods (1D assemblies) formed by alternate crown ether and arylenediamine molecules are the motif of the supramolecular architecture of crystals of molecular associates of 18 crown 6 with tetrafluoro 1,4 and 1,3 phenylenediamines, hexafluoro 2,6 and 2,7 naphthylenedi amines. Molecules in the assemblies are arranged via H bond predominantly between the crown ether oxygen atoms and the polyfluoroarene amino group hydrogen atoms. Influence of the amino groups mutual arrangement and the aromatic framework size on the crystal su pramolecular architecture is characterized. Specific melting heats of the crystalline 1D assem blies of para and pseudo para arylenediamines are higher than those of meta and pseudo meta analogs; the associates having higher melting heats selectively crystallize from solutions of isomeric phenylene or naphthylenediamine mixtures.

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Relationship between the hetarylamine chemical structure, crystal packing in homo- and co-crystals, and fluorescence effects (quenching, bathochromic and hypsochromic shifts).