Nuclear magnetic resonance titration examples

Shortly after the reports of Jorgensen, the Zimmerman group published the first example of the DDD-AAA H-bonding pair 11.12 (Figure 4). The value of exceeded the limit of values accessible by H NMR (nuclear magnetic resonance) titrations accordingly they report a lower limit of > 10 Subsequently, Anslyn... 

Several modem analytical instruments are powerful tools for the characterisation of end groups. Molecular spectroscopic techniques are commonly employed for this purpose. Nuclear magnetic resonance (NMR) spectroscopy, Fourier transform infrared (FTIR) spectroscopy and mass spectrometry (MS), often in combination, can be used to elucidate the end group structures for many polymer systems more traditional chemical methods, such as titration, are still in wide use, but employed more for specific applications, for example, determining acid end group levels. Nowadays, NMR spectroscopy is usually the first technique employed, providing the polymer system is soluble in organic solvents, as quantification of the levels of... 

So far it has been assumed, without any proof, that sulfonic groups in SPPO are attached to aromatic rings. In principle, sulfonic groups could also be attached to methyl groups as in case of other modified PPO polymers, for example, carboxylated PPO or methyl ester carboxylated PPO [22]. Acid-base and conductimetric titrations do not allow distinguishing between aryl and methyl substituted PPO. On the other hand, proton nuclear magnetic resonance ( H NMR) and infrared (IR) spectroscopy provide more information on the structure of SPPO. These techniques can also be used for determination of the DS of SPPO. 

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