The –C≡⃥N and –N≡⃥C Groups

Reactions of Polyphosphoric Acid and Bitumen Model Compounds with Oxygenated Functional Groups: Where Is the Phosphorylation?

“…From their frequencies, their structure could readily be assigned. [18][19][20] The typical absorbance at 1656 cm -1 confirmed that aryl-aryl ketones could form in PPA-modified bitumen, and interestingly an absorbance at 1739 cm -1 also showed that an ester was produced. With FTIR, it was unclear whether it was an arylaryl or an aryl-alkyl ester, however.…”

“…The absence of new absorbances between 600 and 800 cm -1 (not shown) for di-or trisubstituted aromatics 18 indicated that no aromatic ring condensation had occurred. It was also noteworthy that in addition to a new strong C=C peak at 1654 cm -1 , attributed to the α,β-unsaturated ketone, an equally intense C-O band was visible at 1213 cm -1 .…”

“…As such, the 1210 cm -1 absorbance were tentatively attributed to P I-III OC stretching 16 (i.e., phosphenic or phosphonic compounds {one and two hydroxyls, respectively} as opposed to phosphate {three hydroxyls}), and the 1170 and 970 cm -1 absorbances were attributed to aliphatic POC stretches. 16 Combined with the new absorbance at 700 cm -1 , typical of mono-substituted aromatics, [18][19] we speculated that PPA and benzoic acid both catalyzed the opening of the cycloalkyl ring of indan to produce a monosubstituted aromatic-phosphorus compound of the type Ar(CH 2 ) 3 OP(O)(OH) n R m , where the integers n + m = 3. Based on the integration of 1 H NMR signals, the combined yield of the products of the reaction between benzoic acid and indan was estimated at less than 10%, so no attempts were made to separate the three products for a more detailed analysis of their structure.…”

“…It showed a loss in the absorbances typical of para-substituted aromatics at 1512, 1180, and 831 cm -1 , [18][19][20] compensated with new absorbances at 1499, 1473, 812, 754, and 691 cm -1 , the latter two being typical of mono-substituted aromatics. [18][19][20] Such a change in aromatic substitution could only be obtained upon de-alkylation.…”

“…It showed a loss in the absorbances typical of para-substituted aromatics at 1512, 1180, and 831 cm -1 , [18][19][20] compensated with new absorbances at 1499, 1473, 812, 754, and 691 cm -1 , the latter two being typical of mono-substituted aromatics. [18][19][20] Such a change in aromatic substitution could only be obtained upon de-alkylation. Figure 4 shows a possible route to a monosubstituted aromatic, whereupon a quinine intermediate protonated in the para position is subject to double nucleophilic displacement 21 by an anion of PPA to produce two phenol molecules and a non-aromatic phosphorylated by-product.…”