Catenation nitrogen

A density functional procedure has been used to compute the gas-phase heat of formation of the triazolooxadiazole 17, and the calculated value of Ai/f° at 202 kcal moP (903 cal is more than 4 times greater than that of a leading military explosive, l,3,5-trinitrohexahydro-l,3,5-triazine (RDX), 18 (206cal g ), which supports the hypothesis that a high energy content is associated with nitrogen catenation <1995JST(358)63>. 

As with nitrogen, catenation occurs only to a very limited extent. In peroxides and superoxides there are two consecutive oxygen atoms. Only in 03, Oj, and the few Rf03Rf molecules are there well-established chains of three oxygen atoms. There is a four-atom chain in 04F2. 

Figure 14.2 Electrochemically induced molecular rearrangements undergone by the copper catenate 12+/ +. In the text, the subscript 4 or 5 indicates the number of nitrogen atoms coordinated to the metal. This number is explicitly shown on the figure.

CATENATED NITROGEN LIGANDS PART II.1 TRANSITION METAL DERIVATIVES OF TRIAZOLES, TETRAZOLES, PENTAZOLES, AND HEXAZINE... 

This review, which complements an earlier one (Part I) dealing with transition metal complexes of triazenes, tetrazenes, tetraazadienes, and pentaazadienes, examines the coordination chemistry of related cyclic catenated nitrogen ligands. Six-membered rings containing three, four, or five adjacent nitrogen atoms — 1,2,3-triazines, 1,2,3,4-tetrazines, and pentazines, respectively — are either unknown or are relatively unstable species whose coordination chemistry has yet to be explored. 

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