STUDY OF CONFORMATIONAL SENSITIVITY THROUGH 13C NMR CHEMICAL

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<p class="Default" align="center"><strong>ABSTRACT</strong></p> <p class="Default"><strong>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; The </strong><strong>¹³</strong><strong>C&nbsp; Chemical&nbsp;&nbsp; &nbsp;shifts are &nbsp;&nbsp;less sensitive &nbsp;to perturbations such as solvent effect than ¹H NMR Chemical shifts. The &nbsp;spectra &nbsp;&nbsp;of &nbsp;&nbsp;B18C6 &nbsp;&nbsp;and &nbsp;its complex with Na⁺ and K⁺ shows the similarity in&nbsp;&nbsp; &nbsp;both &nbsp;the &nbsp;solvent&nbsp;&nbsp; CDCl₃and Acetone, same closeness reported for DB18C6 in CD₂Cl₂ and also the ether ring conformation are found same for both &nbsp;of &nbsp;these molecules. The ¹³C NMR spectra of &nbsp;DB30C10 are very similar &nbsp;to ¹H NMR but when &nbsp;&nbsp;these &nbsp;&nbsp;&nbsp;molecule &nbsp;&nbsp;complexed &nbsp;&nbsp;with K⁺ , ¹³C NMR &nbsp;&nbsp;spectra &nbsp;are grossly &nbsp;different which indicate different structure &nbsp;in &nbsp;the &nbsp;complex &nbsp;&nbsp;form. &nbsp;&nbsp;&nbsp;&nbsp;The &nbsp;&nbsp;¹³C spin &nbsp;lattice relaxation &nbsp;time (T₁&rsquo;s) &nbsp;for &nbsp;all &nbsp;the protonated&nbsp; carbon &nbsp;&nbsp;&nbsp;&nbsp;of &nbsp;&nbsp;DB30C10 in uncomplexed &nbsp;form &nbsp;are &nbsp;very similar &nbsp;but different&nbsp; &nbsp;in complexed forms. </strong></p>