Structural characterisation of trimethylsilyl-protected DNA bases

Kieran Molloy (1) , Gareth Price (1) , Doug Smith (1) , Gabriele Kociok-Khön (1)

1 Department of Chemistry [Bath]

The structures of the silylated DNA bases, bis-(trimethylsilyl)thymine (1), bis-(trimethylsilyl)cytosine (2), bis-(trimethylsilyl)adenine (3) and tris-(trimethylsilyl)guanine (4), have been determined. 1 is O-silylated and displays no intermolecular interactions. 2 is silylated at both exocylic O, N-positions and forms a chain structure through intermolecular NH...O and NH...N hydrogen bonds. 3 contains two SiMe3 groups, on the exocylic NH and endocyclic N9 position, respectively; of two independent molecules in the asymmetric unit, one dimerises through complementary NH...N hydrogen bonds while the other forms a strained intramolecular hydrogen bond through the same pair of donor and acceptor centres. 4 incorporates N, N, O-SiMe3 moieties and forms chains via bifurcated CH...O/N hydrogen bonds while the NH function remains unexploited. The effects of silylation on these pyrimidine and purine ring structures are also discussed in comparison with the native bases.

Mots clés: Physical Sciences

Kieran Molloy, Gareth Price, Doug Smith, Gabriele Kociok-Khön. Structural characterisation of trimethylsilyl-protected DNA bases. Supramolecular Chemistry, 2008, 20 (08), pp.697-707. ⟨10.1080/10610270701732885⟩. ⟨hal-00513518⟩