N Stretching Vibrations

Gold (I) cyanide [506-65-0] M 223.0, m dec on heating. The lemon yellow powder is sparingly soluble in H2O and EtOH but soluble in aqueous NH3. It is obtained by heating H[Au(CN)2] at 110°. Wash well with H2O and EtOH and dry at 110°. It has an IR band at v 2239cm typical fo C=N stretching vibration. [Handbook of Preparative Inorg anic Chemistry (Ed. Brauer) Vol II 1064 7965.] CARE may evolve HCN. 

The most characteristic feature of the infrared spectra of all 5-mono- and -di-substituted-amino-l,2,3,4-thiatriazoles is a strong band in the 1540-1590 cm range, which without doubt is due to the C=N and N=N stretching vibrations of the heteroaromatic ring system. Various infrared bands between 889 and 1122 cm have been assigned to skeletal vibrations of the thiatriazole ring and a band... 

The only doubly bonded tin compound for which the IR spectrum has been reported is the stannaketenimine [2,4,6-(CF3)3C6H2]2Sn= C=N[2,4,6-(CH3)3C6H2)]. The C—N stretching vibration (2166 cm-1) is shifted relative to that of mesityl isocyanide (2118 cm-1) this phenomenon is also observed for isocyanide-transition-metal complexes.87... 

For the series of silver complexes with cyanide, the C-N stretching vibrations are observed as follows. The species containing three or four cyanide ions are observed only in solutions containing high concentrations of CNT... 

Compared to the structures of Li+-water solvates, the structures of Li+-acetonitrile solvates are in general less studied. The Li+ ion was found to be four coordinate with the use of different techniques, e.g., by NMR where acetonitrile was gradually replaced by water in a 1.6 M solution of LiC104 (130), or based on IR intensities measured for the acetonitrile C-N stretching vibration (131,132). Even mixed coordination of a counter ion and acetonitrile were reported to be four coordinate, viz., in [Li(CH3CN)3Br] for 0.58 M LiBr in CH3CN (133). Extensive... 

For further investigations f-BuNC, which is isolobal to CO, was used. With PhLi and t-BuLi, the characteristic vibrational mode of the lithium isonitrile adduct (2135 cm ) was observed at a lower wavenumber than that of the free isonitrile (2179 cm ). Unfortunately, n-BuLi did not undergo complexation. As indicated by the C=N stretching vibrational mode at 1510 cm, only f-BuLi—CN—R reacted further to afford the lithiated Schiff base up to —20°C (equation 2) . ... 

Doubts about C=N stretching vibrations of dithiazolines (53) and (54) and of the 3-imino-dithiazolidine (44) appeared, when Dickore et al. <62AG(E)594> reported that they can be distinguished as they have between 1550-1590 and 1630 cm respectively, but later workers assigned a 1600 cm for compounds which were claimed to be of type (44) though... 

Treatment of 5-ethoxy-l,2,3,4-thiatriazolium tetrafluoroborates (161) with aromatic amines in boiling benzene affords yellow crystalline 5-arylamino-l,2,3,4-thiatriazolium salts (166) in good yields (60-70%) (Scheme 35). These are deprotonated with warm ethanolic aqueous sodium hydroxide to give the red crystalline mesoionic l,2,3,4-thiatriazolium-5-aminides (20). The mesoionic compounds show a strong IR absorption in the region 1580-1590 cm which can be assigned to the exocyclic (7=N stretching vibration. UV and visible spectra are reported e.g. (20a) 279 (e... 

The N=N stretching vibration of a symmetrical trans-azo compound is forbidden in the IR but absorbs in the 1576 cm-1 region of the Raman spectrum. Unsymmet-rical para-substituted azobenzenes in which the substituent is an electron-donating group absorb near 1429 cm1. The bands are weak because of the nonpolar nature of the bond. 

Also present in this region are the C—C and C=N stretching vibrations (Scheme 3.9), but these are generally much weaker than the carbonyl absorptions. 

X-Ray diffraction shows that the [Pt(CN)6]2 ion is regular octahedral with linear Pt—C—N bonds.3"2 The IR and Raman spectra of K2[Pt(CN)6] have C—N stretching vibrations at higher frequencies and C—N force constants which are larger than the corresponding divalent complexes.303,304 This correlates with less n back-donation from the metal to the empty n orbitals of the cyanide ligand in the PtIV complexes. 

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