Amines, 77 model compound comparisons

Treatment of the precursors with decylamine resulted in a high level of chemiluminescence activity. Taking the activity obtained with decylamine as 100%, the activities obtained with other amines were methylamine, 5% hexylamine, 23% octylamine, 39% and dode-cylamine, 55%. For comparison, the Panellus precursors, PS-A and PS-B, are best activated with methylamine, and a synthetic model compound, K-l, is best activated with hexylamine. 

Now, the question arises to what extent the thermodynamic information on the low-molecular-weight model compounds can be applied to real epoxy-amine network polymers. A clear answer to this question is given by a direct comparison of the... 

Abstract—The nature of the product of the reaction between an aminated silane and carbon dioxide was re-examined with the aid of simple model compounds, several amines, and several aminosilanes. Since the reaction products previously proposed include the amine bicarbonate and a carbamate derived from the amine, ammonium bicarbonate and ammonium carbamate were studied as models for the anions. Carbon dioxide adducts of neat model amines were prepared and studied. Results from a variety of techniques are summarized. Among the most useful was Fourier transform infrared (FTIR) spectroscopy of fluorolube mulls. FTIR spectra were distinctive and assignments characteristic of the two species were extracted from the spectral data. Comparisons of these assignments with the products of the reaction between carbon dioxide and various amines were made. The results indicate that alkylammonium carbamates are the principal product. Nuclear magnetic resonance (NMR) spectra in D20 indicated much dissociation and were not helpful in defining the products. 

Infrared spectra closely resembled those of the corresponding polyimides prepared from dianhydride, and the corresponding diamines, although absorptions arising from unreacted amine and anhydride were present in the latter. (A comparison is shown in Figure 1, along with the spectrum of a model compound.)... 

The synthesis of model compounds mimicking the structural characteristics of the possible subunits, and the comparison of their spectra with that of the hb polymer, represents a common method for assigning signals to subunits. This procedure, for the assignment of urea and urethane carbonyl carbon signals of a hb poly(urea urethane) synthesized from an AA (2,4-toluylene diisocyanate) and B2 B (diethanol amine) monomer [94], is shown in Figure 24.3. 

Dipole moments in amines obtained from the same set of models used in previous comparisons are compared with experimental values in Table 10-3. These and further data (on oxygen, silicon, phosphorous and sulfur compounds) are given in Appendix AlO (Tables AlO-9 to AlO-16), and mean absolute errors corresponding to the full set are summarized in Table 10-4. In addition, graphical comparisons of calculated and experimental dipole moments have been provided for selected models (Figures 10-1 to 10-11). Circular markers (o) designate molecules with heteroatoms. 

Topics which have formed the subjects of reviews this year include excited state chemistry within zeolites, photoredox reactions in organic synthesis, selectivity control in one-electron reduction, the photochemistry of fullerenes, photochemical P-450 oxygenation of cyclohexene with water sensitized by dihydroxy-coordinated (tetraphenylporphyrinato)antimony(V) hexafluorophosphate, bio-mimetic radical polycyclisations of isoprenoid polyalkenes initiated by photo-induced electron transfer, photoinduced electron transfer involving C o/CjoJ comparisons between the photoinduced electron transfer reactions of 50 and aromatic carbonyl compounds, recent advances in the chemistry of pyrrolidino-fullerenes, ° photoinduced electron transfer in donor-linked fullerenes," supra-molecular model systems,and within dendrimer architecture,photoinduced electron transfer reactions of homoquinones, amines, and azo compounds, photoinduced reactions of five-membered monoheterocyclic compounds of the indigo group, photochemical and polymerisation reactions in solid Qo, photo- and redox-active [2]rotaxanes and [2]catenanes, ° reactions of sulfides and sulfenic acid derivatives with 02( Ag), photoprocesses of sulfoxides and related compounds, semiconductor photocatalysts,chemical fixation and photoreduction of carbon dioxide by metal phthalocyanines, and multiporphyrins as photosynthetic models. 

Interestingly, a detailed picture of both the thermolysis mechanisms and the role of bonds which compose poly(B-alkylaminoborazines) on the degree of crosslinking and processability could be provided by synthesizing asymmetric 5-alkylaminoborazine models. We developed a route through the two-step nucleophilic reaction of 5-trichloroborazine with various amine derivatives yielding molecular compounds 1-3 [37]. Comparison was made with the symmetric 5-trimethylaminoborazine (4) that provided melt-spinnable polymers as described above (Figure 14.5). 

Investigations along these lines are then confronted with another problem, namely that the relative activity, in comparison with a standard compound such as imipramine (1), may differ essentially in the various animal models aimed at detecting one and the same property, such as noradrenaline re-uptake. Additional pharmacological properties of the studied compound may affect the various test models in different manners. Also basic properties of the test systems, e.g. the turnover rate of the biogenic amine involved in various strains of animals, may determine the results critically. These latter circumstances may be the cause of different results being obtained in different laboratories. For that reason, a short critical appraisal of the most commonly used methods seems appropriate. 

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