Avance 400 mhz ultrashield nmr spectrometer

¹H NMR and ¹³C NMR spectra were recorded on either a Bruker Avance 400 MHz Ultrashield NMR spectrometer or a Bruker Avance 500 MHz NMR spectrometer. Mass spectrometric analysis was performed on a LCT Premier mass spectrophotometer. All chemicals were purchased from Sigma–Aldrich, BDH, or Apollo Scientific and used without further purification.
Oligonucleotides listed in Table 3 were purchased from Eurogentec (Belgium). Complexes 1 and 2 a–c were dissolved in a mixture of DMSO (95 % by volume) and 1 mm HCl aqueous solution (5 % by volume) to give 2.0–3.0 mm stock solution. All solutions were diluted to 1 mm with DMSO before use. They were then further diluted using suitable buffer to the appropriate concentration.

¹H NMR, ¹³C NMR and ³¹P NMR spectra were recorded on either a Bruker Avance 400 MHz Ultrashield NMR spectrometer or a Bruker Avance 500 MHz NMR spectrometer (for complete assignment of ¹H and ¹³C NMR spectra see ESI). Electrospray ionisation mass spectra were obtained on a Bruker Daltonics Esquire 3000 spectrometer. Compounds 1^{28 (link)}, 2^{29 (link)} and 3^{30 (link)} were prepared following previously reported procedures (see ESI). While compounds 5, 8 and 9 have been previously reported^{31 (link)}, they were prepared by different routes as detailed in the ESI.