engleski

Experimental and quantum chemical study of ferrocenyl-substituted nucleobases

Nucleobases substituted by ferrocenyl moiety present interesting organometallic conjugates due to their structures which incorporate both biologically and electrochemically active components. Synthetic procedures for preparation of N1- and N3-ferrocenyl substituted pyrimidine bases (thymine, cytosine) and N9-ferrocenyl substituted purine base (adenine) have been developed. The position of substitution in products has been confirmed by spectroscopy methods (NOESY-NMR, IR). Quantum chemical calculations (DFT level of theory) have been employed to rationalize the preferential reaction of ferrocenecarbonyl chloride with N1-nitrogen atom in pyrimidine nucleobases. The calculated energy of activation for the reaction at N3-position is ca. 30 kJ/mol higher than the barrier for the corresponding reaction at N1-position. In addition, N1-ferrocenyl substituted nucleobases have been calculated more stable than their N3-substituted counterparts. Substitution of pyrimidine and purine bases with the ferrocenyl moiety perturb some important intrinsic properties of the bases, such as keto-enol tautomerism and hydrogen bonding. It is expected that ferrocenyl substituted nucleobases can participate in a novel type of base pairing.

ferrocene; nucleobase; synthesis; computational chemistry

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