177-1,2,4-Triazole, crystal structure

The crystal structure analysis of the parent 1,2,3-triazole in the solid state unambiguously demonstrated that it crystallizes as a 1 1 molecular complex of both possible tautomers 24a and 24b, linked by a N-H - N hydrogen bond [97AX(C)1846]. 

An interesting Mossbauer study has been reported on the dinuclear SCO complex [Fe2 (PMAT)2](BF4)4-DMF (PMAT 4-amino-3,5-bis [(2-pyridylmethyl) amino]methyl -4H-1,2,4-triazole), where thermal ST occurs from [HS-HS] to the stable endproduct [HS-LS] [32]. The molecular structure and magnetic behavior of this complex was reported earlier by Brooker et al. [33, 34] (Fig. 8.15). At ca. 225 K, the complex undergoes a sharp half ST from the HS state, T2, to a state containing 50% HS and 50% LS, Af, isomers. The single-crystal structural analysis... 

The crystal structures of [Fe(2,6-bis(triazol-3-yl)pyridine)2](N03)2.4H20 and [Ni(2,6-bis(triazol-3-yl)pyridine)2]Cl2.3H20 revealed that the tridentate ligand coordinates to the metal(II) ion using both N-4 atoms of the two... 

The crystal structure of [Fe2(totrz)5(NCS)4]2[Fe(totrz)2(NCS)2(H20)2]-n-H20, a compound obtained by self-assembly of 4-(p-tolyl)-l,2,4-triazole... 

In the crystal structure of [Fe3(etrz)6(H20)6](CF3S03)6 (etrz = 4-ethyl-1,2,4-triazole) the central Fe(II) ion is surrounded by six triazole ligands thus establishing an FeN6 chromophore. These triazole ligands are Nl,N2-... 

X-Ray analyses of azapentalenes have been used to determine the structure of products from reactions with ambiguous reaction sites or with concomitant rearrangements. Thus, the X-ray structure of the /3-D-[l,2,4]triazolo[4,3-3][l,2,4]triazole 2 establishes that glycosylation has occurred at the N-l position furthermore, it also shows that the compound is the ft-anomer. In addition to intermolecular hydrogen bonds in the crystal structure an intramolecular hydrogen bond is extended from OH-5 to N-7 <1984NN187>. The X-ray structure of the inner salt of compound 1 has been determined... 

Kim s group in Seoul report the application of another of the E. coli ATs, the aromatic l-AAT encoded by the tyrB gene, to enrich the D-component of racemic preparations of alanine substituted at the /3-position with pyrazole, triazole, and imidazole. They also carried out an in silico investigation based on the crystal structure (PDB 3TAT) providing a reasonable rationalization (and therefore also potentially prediction) of substrate specificities. 

The crystal structure of 3,4,5-triamino-l,2,4-triazole hydrobromide has recently been reported (Seccombe and Kennard, 1973) and shows that protonation occurs on N-2. The structure of the cation is best described by the resonance [90], although there is some spreading of charge on to N-4 as well. 

The acid-base properties of the ground and excited states of [Ru(bpy)2(im)2] and [Ru(bpy)2(l,2,4-triazole)2] have been investigated. Both complexes are stronger acids in the excited than the ground states." Representative triazoles, L or HL, have been incorporated into the complexes [Ru(bpy)2L]"" (n = 1 or 2). Electronic spectroscopic and electrochemical properties have been reported all the ligands are weaker tt acceptors than bpy." " The crystal structures of... 

The effect of the 7V-substituents on the geometry of the 1,2,3-triazole ring is studied by analyzing 35 x-ray crystal structures of substituted triazoles and benzotriazoles. The analyses employ least-squares estimation of parameters. Two models for the substitution effects on the endocyclic angles... 

Table 4 presents molecular dimension parameters of 1,2,3-triazole and 2-methyl-4-trinitromethyl-2//-1,2,3-triazole based on electron diffraction (ED) data alone, joint analysis of electron diffraction and microwave spectral data (ED-MW), and ab initio calculations. The corresponding molecular dimensions of 1,2,3-triazoles in the crystalline state obtained by x-ray diffraction (XD) are the average values based on <85ACS(A)259>. Figure 5 shows the bond distances and angles of the crystal structure of 2-phenyl-4-chloro-1,2,3-triazole <84ACS(A)497>. As examples of 4,5-unsubstituted H-... 

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