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1,2-Dinitroguanidine

“…Even in the presence of conjugation between the primary nitramine and the nitroguanyl groups, which strengthens the CÐN4 bond, this bond is the weakest CÐN bond observed (Table 1). In accordance with this fact, compound (I) and other nitrimines with electron-acceptor substituents (1methyl-1-nitroso-2-nitroguanidine, 1-methyl-1,2-dinitroguanidine, nitroguanylazide and 1-nitro-2-nitriminoimidazolidine) readily take part in nucleophilic replacement reactions, which are accompanied by the breaking of the CÐN4 bond (Astratiev et al, 2003;Astachov et al, 2003;Vasiliev et al, 2004). Nitrimines which do not contain electron-acceptor substituents have an analogous CÐN bond length not greater than 1.330 A Ê (Allen, 2002) and, consequently, an essentially diminished reaction ability in nucleophilic replacement reactions (McKay, 1951).…”

“…The formal CÐN3 single bond [1.303 (2) A Ê ], not the formal C N2 double bond [1.341 (2) A Ê ], has the shortest CÐ N bond distance in the molecule. This peculiarity of the structure, which is associated with the possibility of conjugation and redistribution of the electron density and which contradicts the representation shown in the Scheme above, has been observed in other nitrimines (Nordenson, 1981a,b;Bracuti, 1999;Astachov et al, 2002Astachov et al, , 2003Vasiliev et al, 2003Vasiliev et al, , 2004. The planar con®guration of atom N4 (sum of valence angles = 359.5 ), the almost planar geometry of the whole molecule and the average bond-length values testify to through-conjugation in the molecule of (I), i.e.…”

“…The same situation is found in other nitrimines with electronacceptor substituents, viz. 1-methyl-1-nitroso-2-nitroguanidine (Nordenson & Hvoslef, 1981;Rice et al, 1984), nitroguanylazide (Vasiliev et al, 2001), and 1-methyl-1,2dinitroguanidine and 1-nitro-2-nitriminoimidazolidine (Astachov et al, 2003;Vasiliev et al, 2004), where the lengths of the analogous CÐN bond are in the range 1.379±1.408 A Ê . Nevertheless, the CÐN4 bond in (I) is distinctly shorter in comparison with the analogous CÐNHNO 2 bond in primary alkylnitramines, viz.…”

“…On the other hand, we cannot con®dently af®rm that there is an intermolecular N3ÐH1Á Á ÁO1 H hydrogen bond, because of poor geometry parameters (Table 2). At the same time, there are no NÐHÁ Á ÁN2 hydrogen bonds in the crystal structure of (I), although these are present in nitroguanidine (Bryden et al, 1956;Choi, 1981;Bracuti, 1999) and some of its derivatives (Nordenson & Hvoslef, 1981;Nordenson, 1981a,b;Rice et al, 1984;Astachov et al, 2003;Vasiliev et al, 2003). In general, the net of hydrogen bonds in the crystal stucture of (I) is less developed than in nitroguanidine compounds.…”

Powder diffraction crystal structure analysis using derivative difference minimization: example of the potassium salt of 1-(tetrazol-5-yl)-2-nitroguanidine

“…From the structural characteristics available for the potassium salt of TetrNQ and other nitroguanidine derivatives (Nordenson, 1981;Nordenson & Hvoslev, 1981;Rice et al, 1984;Oyumi et al, 1987;Bracuti, 1999;Astachov, Vasiliev, Molokeev, Kruglyakova & Stepanov, 2002;Astachov, Vasiliev, Molokeev, Kekin, Kruglyakova & Stepanov, 2003;Vasiliev et al, 2003a,b;Allen, 2002), similar delocalizations of theelectron density in 1-(tetrazol-5-yl)-2-nitroguanidine may be expected, at least for the nitroguanyl molecular fragment.…”