Structure nitrogen fluorides

All nitrogen fluorides are very reactive, often dangerous species, generally powerful oxidizers. Such compounds as NF3 (5F = +143) and N2F4 would virtually never be encountered in an organic synthesis laboratory, and no NMR data have even been reported for the latter compound. NF3 has a pyramidal structure, with F—N—F bond angles of -102°. 

In the latter formulae the octets of the halogen atoms are not marked. Recently a second nitrogen fluoride, N2F2, has been prepared the only possible structure is... 

Contents Trifluoromethyl Aromatic Compounds (R. Filler) Aliphatic Fluoro-amino Acids (F. Loncrini and R. Filler) Fluoro-alcohols (S. K. De and S. R. Palit) Polyfluoroaromatic Derivatives of Metals and Metalloids (S. C. Cohen and A. G. Massey) The Chemistry of Organic Nitrogen Fluorides (J. P. Freeman) Fluorine Compounds of lenium and Tellurium (B. Cohen and R. D. Peacock) Madelung Constants as a New Guide in the Structural Chemistry of Solids (R. Hoppe). 

The fluoride SF4 forms when a mixture of fluorine and nitrogen gases is passed over a film of sulfur at 275°C in the absence of oxygen and moisture. Write the Lewis structure of sulfur retrafluoride and give the number of electrons in the expanded valence shell. 

Nitrile sulfides (37) have some, admittedly slight, structural affinity with the other nitrogen-sulfur reagents discussed in Section IV. They are unstable reactive intermediates that can be generated by the thermolysis of 1,3,4-oxathiazol-2-ones (38) or of 1,3,4-oxathiazoles (39).41 42 An alternative preparation is by the elimination of 2 moles of hydrogen fluoride from imini-sulfur difluorides (Scheme 5).43 Nitrile sulfides (37) are capable of undergoing... 

The high reactivity of di- and trinitrophenyl fluorides towards nucleophiles has been used for the arylation of various N-nucleophiles. A method was developed for the determination of N-terminal amino acids in peptides. Thus, nucleophilic attack of the amino acid nitrogen at Sanger s reagent (2,4-dinitrophenyl fluoride, 4), hydrolysis and subsequent analysis of the N-(2,4-dinitrophenyl)amino acid allows determination of the amino acid.162,163 Although this method has been replaced by more efficient procedures, it marked a milestone in the elucidation of peptide structures (Nobel Prize 1958). A variety of N-nuclcophilcs (no amino acids) which have been used in the nucleophilic substitution of 2,4-dinitrophcnyl fluoride is listed. 

Electropositive fluorinating agents are categorized in distinct classes as (1) fluoroxy reagents, in which the fluorine is bound to an oxygen atom (for reviews, see references 1,2, 3, 4, 5, and 6) (2) fluoraza reagents, in which the fluorine atom is bound to the nitrogen atom of either an amide or ammonium ion structure (for a partial review, see reference 6), (3) xenon difluoride, in which the fluorine atoms are bound to xenon (for reviews, see references 5, 7, 8, and 114) and (4) perchloryl fluoride, in which the fluorine atom is bound to the chlorine atom of the perchloryl function (for a review, see reference 9). 

As the inner salts are generally unstable and insoluble, they cannot be manipulated and their structures were therefore inferred from those of the more stable nitrogen analogues. The inner oxonium salt from boron fluoride, when examined at low temperatures, was found to contain a molecule of ether of crystallization which was held very tenaciously and was involved in the complex decomposition of the salt at higher temperatures. The salt from antimony pentachloride did not contain this molecule of ether and decomposed to ethyl chloride and a mixture of alkoxy antimony tetrachlorides. The stannic chloride decomposed in at least two ways,... 

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