Synthesis and characterization of cis-[(PPh3)2Pt{9-MeAd(-H),N6N7}]X (X−= NO3, PF6): The first example of a platinum(II) complex containing the N6,N7-chelated 9-methyladenine anion

Synthesis, characterization and cytotoxic properties of platinum(II) complexes containing the nucleosides adenosine and cytidine

“…2, the first resonance correlates with the adenine H8 proton at δ 5.83 and both of them show correlation with the N(6)H proton at δ 4.64 (partially overlapped with the ribose H2′ multiplet, at 300 MHz). These results led to the conclusion that the nucleoside is chelated to the metal through the N6 and N7 atoms, as previously found for the nucleobase 9-methyadenine [26]. Selected 31 P and 1 H NMR data of the nucleosides and the corresponding model nucleobase are collected in Table 1.…”

Solvent Effects on Nitrogen Chemical Shifts

“…Instead, the mononuclear of N6,N7-bis-coordinated Pt(II) complex 201 was formed quantitatively, and could be isolated in 71% yield (Scheme 4) [116]. The δ 15N and Δ 15N coord of 201 were very similar in chloroform-d and dimethyl sulfoxide-d 6 solvents (Table 16).…”

“…The obtained jΔ 15N coord j indicated that all three coordination sites, N1, N7, and N6, of 9-MeAd are involved in the Pt(II) coordination for some complexes, which conclusion was confirmed by X-ray crystallography for some of the complexes. Proposed reaction pathways with dimethyl sulfoxide-d 6 or dimethylformamide-d 7 as solvents and PMePh 2 as the P ligands are depicted in Scheme 3 and the chemical shifts are given in Table 15 [111,113,114,116] [113] recalculated in respect to neat CH 3 NO 2 by subtracting 1.9 ppm relative originally reported chemical shift. [82] The δ 15N lig for 9-MeAd for DMSO-d 6 is given in [111].…”

“…Depending on the nature of the counterion, the latter [116] and are recalculated in respect to neat CH 3 NO 2 by subtracting 1.9 ppm relative original shift value [82]. The δ 15N lig for 9-MeAd is derived from a DMSO-d 6 solution [111].…”

“…Pt(II) complexes with nitrogen donors trans to Cl have smaller jΔ 15N coord j than those having nitrogen trans to another nitrogen, reflecting the trans effect. Pt(II) complexes of phosphorous-containing trans ligands coordinate either at the pyrimidinic N1 or at the pyrazolic N7 [110,[113][114][115][116]. The jΔ 15N coord j of these complexes are in the range of $50-65 ppm, suggesting the nitrogen donor to be in trans to phosphorous.…”