Comparison to NH

Flame Retardants. The amount of research expended to develop flame-retardant (FR) finishes for cotton and other fabrics has been extremely large in comparison to the total amount of fabrics finished to be flame retardant. The extent of this work can be seen in various reviews (146—148). In the early 1960s, a substantial market for FR children s sleepwear appeared to be developing, and substantial production of fabric occurred. In the case of cotton, the finish was based on tetrakis(hydroxymethyl)phosphonium chloride (THPC) or the corresponding sulfate (THPS). This chemical was partly neutralized to THPOH, padded on fabric, dried under controlled conditions, and ammoniated. The finish was subsequently oxidized, yielding a product that passed the test for FR performance. This process is widely preferred to the THPOH—NH process. 

Formation of the adduct with dirhodium complex [6] has significantly changed the chemical shift of the compounds in which proton transfer occurred, for example, for the adduct of iV-(5-nitrosalicylidene)-2-ami nobutane, the chemical shift was —198.2, which was shielded by of 110 ppm in comparison to that in the starting Schiff base.12 The large signal shift was due to the shift of the proton transfer equilibrium towards NH tautomer. For the adduct of N-(salicylidene)-2-aminobutane, existing in the OH-form, the 15N chemical shift has changed from —87.5 to — 84.6 ppm. 

In comparison to the porphyrins, the corrin nucleus contains one less atom in its innermost ring (that is, it contains a 15-membered ring) and, on coordination, only one NH proton is lost to give the macrocycle a single negative charge. A cobalt corrin complex occurs as part of the structure of vitamin B12. 

This can be compared to S°(NHj) = 46.0 S°(HaO) = 45.1 (44.3 when corrected to internal symmetry 3 for comparison with NHs) jS°(CHj) = 44.5 (47.3 corrected to symmetry 3). In these compilations standard states are the ideal gas at 1-atm. pressure and 25°C. Unless otherwise stated all values are taken either from the NBS compilation Circ. No. 500 or else the A.P.I. project report No. 44. If the CH3 is considered planar with symmetry 6 and spin /a, a value closer to 46 might be more appropriate. 

The reactions of silver(I) with 1,5-diphenyl thiocarbazone (56 dithizone = HaDz) by comparison to thiosemicarbazones have been thoroughly investigated.442,444 Dithizone has for many years been used as a colorimetric reagent for trace metal ions. Its metal complexes are of two types, the so-called primary and secondary dithizonates. Primary dithizonates are generally formed at low pHs where the ligand becomes mono depronated (pA = 4.5) but retains the NH proton. Secondary dithizonates are formed in the presence of an excess of metal and/or at higher pH values where the ligand becomes fully deprotonated. Since it has been estimated that for free dithizone pK2 > 15, the second proton obviously becomes labilized in the presence of metal ions. 

For comparison purposes, between a-chitin and its deacetylated derivative chitosan, FT-IR spectra were obtained for a-chitin and chitosan of different molecular weights. It is clear that the split bands at about 1650 and 1620 cm in the a-chitin spectra (corresponding to amide I) appear as one band in the spectra of chitosans of molecular weights 1300-28,000 Da (Fig. 2.16). Also the band corresponding to NH in the range of... 

However, for the compounds in the amide series, the O-linked form is almost totally formed in the absence of base. In fact, in such systems, the secondary amide groups present in close vicinity to the porphyrin ring induce greater stabilization by dipole-dipole interactions between the NH dipoles and the central negative charges in comparison to compounds having ether-linked... 

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