Amine spectroscopic properties

The spectroscopic properties of the /V-nitrosamines, especially the nmr and mass spectra, vary widely depending on the substituents on the amine nitrogen (44—47). The nmr spectra are affected by the E—Z isomerism around the N—N partial double bond and by the axial—equatorial geometry resulting from conformational isomerism in the heterocycles (44,45). Some general spectral characteristics for typical dialkylnitrosamines and simple heterocycHc nitrosamines are given in Table 1. 

The complexes [LCo(p-02)(p-OH)CoL] [L = en, trien, dien, tetra-ethylenepentamine, or tris-(2-aminoethyl)amine] have been studied, and the new complexes [[Co(imidazole)(gly)2 202],4H20 [ Co2(imidazole)2-(gly)402 0H],3H20, and [Co(imidazole)(gly)2(02)H20] have been prepared The spectroscopic properties of various p-peroxo- and p-superoxo-cobalt(iii) complexes have been examined. The singly-bridged p-peroxo-compounds have a strong band at 300 nm, whereas this falls at 350 nm for p-peroxo-p-hydroxo-complexes and two peaks at 480 and 700 nm are observed for p-superoxo-species. The i.r. spectra of p-peroxo-bridged complexes of cobalt(iii)-cyclam have been reported. ... 

Diselenophosphate complexes are prepared from the interaction of metal salts and complexes with appropriate diselenophosphoric acid or its salt. The acids are obtained from the reaction of phosphorus(V) selenide with alcohols 229). The preparation of phosphorus(V) selenide and its reactions with alcohols 229) and amines 22°) have been described and a variety of complexes reported (Table 4). The biological activity of these compounds does not seem to have described but the exercise of extreme caution when handling these materials is recommended. Zingaro and his coworkers 229-232) thoroughly characterized the thermal and spectroscopic properties of a number of compounds. 

The Copper Site. In a crystal form of ECAO shown to contain catalytically-active protein (Parsons et al., 1995), the eopper is penta-coordinated in approximate square pyramidal eonfiguration by four basal (equatorial) ligands (His 524, His 526, His 689 and a water [We]) and an apical (axial) water (Wa). The presence of equatorial and axial waters had been first reported by Barker et al. (1979) from EPR, water proton relaxation and kinetic studies on pig plasma amine oxidase and the prediction of histidines and waters as the copper ligands came from EXAFS studies by Scott and Dooley (1985). The equatorial water (We) is labile and not always present. In the HP AO structure (Li et al., 1998) it is present in some, but not all, of the six independent subunits in the same erystal. A comprehensive discussion of the spectroscopic properties of the copper site in amine oxidases, including the exchange rates for the equatorial and axial waters, is given in the review by Knowles and Dooley (1994). 

Abramczyk H, Kroh J. (1994) Spectroscopic properties ofthe solvated electron in water, alcohols, amines, ethers and alkanes. Radiat Phys Chem 43 291-297. 

The electronic structure, in particular the electronic spectroscopic properties, of the whole class of cobalt amine complexes may be reduced to a discussion of the central Co-Ne core. This disregards, of course, the charge-transfer transition that in these compexes typically occurs around 250 nm. The geometrical structure is either octahedral or is defined in terms of a subgroup of the cubic point group Oh, where the... 

The near-infrared absorption of primary, secondary and tertiary aliphatic and aromatic amines has been studied extensively since 192530,31 in order to define the spectroscopic properties of the NH bond in a large number of amines. 

In fact, the first effect of intramolecular hydrogen bonds in the condensed phase is the self-association of amines (as well as alcohols), affecting their physical and spectroscopic properties, in particular the N—H frequencies in the infrared spectra. 

We have already alluded to the diversity of oxidation states, the dominance of 0x0 chemistry and the cluster carbonyls. Brief mention should be made too of the tendency of osmium (shared also by ruthenium and, to some extent, rhodium and iridium) to form polymeric species, often with oxo, nitrido or carboxylato bridges. Although it does have some activity in homogeneous catalysis (e.g. of CM-hydroxylation, hydroxyamination or amination of alkenes, see p, 558, and occasionally for isomerization or hydrogenation of alkenes, see p. 571), osmium complexes are perhaps too substitution-inert for homogeneous catalysis to become a major feature of the chemistry of the element. The spectroscopic properties of some of the substituted heterocyclic nitrogen-donor complexes may yet make osmium an important element for photodissociation energy research. 

The first flowcell experiment was reported in 1975, and some years later in 1979 Vidrine reviewed the most important points of this technique, limited at that time to size-exclusion chromatography (SEC). The use of flowcell methods with normal- and re-versed-phase chromatographic separations has proven more difficult, since for a successful coupling the spectroscopic properties of the solvent system should meet some minimum requirements. In this respect deuterated solvents seemed to be promising, and numerous applications have been reported on normal-phase, flowcell HPLC/FT-IR, in which deuterated or halogenated solvents were used. Hydrocarbons, esters, ketones, phenols, amines and... 

The coordination of tris(pyrazolyl)amine and bis(pyrazolyl)amine ligands toward [Rh(/r-Cl)(cod)]2 was studied and the crystal structure of the trimetallic compound Rh3Cl3(cod)3(tdma) was reported. Trispyrazolylborate ligands also provided a series of complexes of the type TpRh(LL) (LL = nbd or cod), whose NMR spectroscopic properties and structural features were studied. The fluxional behavior of complexes of formula Tp Rh(LL) (LL = nbd, 2CO, cod R = H, Me, Ph, Br) was studied by means of NMR spectroscopy. Two K -square-planar isomers and one re -pentacoordinated complex were observed. The structure of the complex K -Tp Rh(nbd) was confirmed by X-ray diffraction. The hapticity of the Tp ligand was also studied on the basis of the i B-H) obtained by IR spectroscopy. Reactions of [Rh(/r-Cl)(nbd)]2 with a series of bis- and tris(azolyl) methanes 388, 389, 390, 391, and 392 were also reported. ... 

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