N2 adduct

Indicative of the intermediate products of the NO decomposition process, new bands appeared in the 2375—2215 cm region (Fig. 7b). The complex absorption in the 2375-2345 cm range with a maximum at 2355 cm indicates the formation of Cu (N2) adducts (72,74,81). This band has a complex shape because of the presence of co-adsorbed NO species, formed upon disproportionation of NO (81). The relatively stronger absorption in the 2270-2220 cm range reflects the presence of N2O molecules weakly bonded in the zeolite channels (61,72,74,81). In this case, the activation barrier for the desorption of the products from the catalytic site (AEc in Fig. 1) is much lower than kT at room temperature, and most of the O2 and N2 molecules were in the gas phase and thus not detectable by IR spectroscopy. 

Variable-temperature Raman data for [C3H7NH3]2SiF6 were used to probe the phase transition at 223K.464 The IR spectrum of the SiCl2.N2 adduct in Ar/ N2 matrices included vsSiCl (511.2, 508.9. 506.5 cm-1) and vasSiCl (500.1,496.9, 495.1 cm-1). Cl2Si(N2)2 shows features at 498.7 and 493.5 cm-1. All data refer to the major isotopomers.465... 

Chung, F.L. and Hecht., S.S. (1983) Formation of cyclic l.N2-adducts by reaction of deoxyguanosine with a-acetoxy-N-nitrosopyrrolidine, 4-(carbethoxynitrosamino)butanal, or crotonaldehyde. Cancer Res., 43, 1230-1235. 

Zang, H., Harris, T.M., and Guengerich, F.P. (2005) Kinetics of nucleotide incorporation opposite DNA bulky guanine N2 adducts by processive bacteriophage T7 DNA polymerase (exonuclease-) and HIV-1 reverse... 

Different types of damage are repaired at different rates thus, the C8-guanine adduct of 2-acetylaminoluorene and other aromatic amines is removed at a considerably faster rate than the N2 adduct, perhaps because the latter does not lead to major denaturation of the double helix. In addition, significant species and tissue differences in rates of repair exist. For example, damage to liver DNA by dimethylnitrosamine is more slowly repaired in the hamster than in the rat. In mice and rats, the residues of... 

The study of MoFe3S4 cubane clusters (Section 8.22.2.3.5) has not yielded N2 adducts, although some iron-sulfur and molybdenum-iron-sulfur clusters may be catalysts for the electrolytic reduction of N2. Coucouvanis and co-workers have discovered that a number of Mo/Fe cubanes catalyze the reduction of hydrazines and diazenes to ammonia and/or amines. ... 

Because of the difficulty in analyzing reactions of N2, and because of the complete lack of spectroscopic evidence for N2 adducts, biochemists have sought other substrates that could give... 

N2 to form [ (ri=-C5Me5)2Sm 2( -r tl -N2)] (306) (Scheme 77). In solution, an equilibrium exists between [ (r -C5Me5)2Sm 2(li-q q -N2)] (306), free N2 and the base-free [(r -C5Me5)2Sm] (305) and the molecular structure of the N2 adduct reveals a weakly activated N2 ligand based on the N—N bond distance of 1.088(12) which is even shorter than that in free N2 (1.0975 A) and has been rationahzed by disorder in the atomic positions of the N atoms. However, other structural features and spectroscopic data such as the Sm-C(Cp ) bond distances and the NMR chem-... 

Fig. 3.13 Structural representation of the N2 adduct of FeMoco obtained from minimized coordinates from the Norskov study (intermediate B in Fig. 3.10). Arrows indicate bonds to which the distances provided refer.

---