Substitution process in phosphine thiopurine palladium complexes

Water-Soluble Cp Ruthenium Complex Containing 1,3,5-Triaza-7-phosphaadamantane and 8-Thiotheophylline Derivatives: Synthesis, Characterization, and Antiproliferative Activity

“…The 13 C{ 1 H} NMR was also in agreement with the proposed composition for 2 . The signal for the S-CH 3 arises at 14.15 ppm that is close to that for 8-MTTH (14.00 ppm). , The 31 P{ 1 H} NMR spectrum showed a single signal at −25.19 ppm due to phosphorus-coordinated PTA. Therefore, the spectroscopic data for 2 are similar to the corresponding found in previously reported 8-MTT − complexes where the thiopurine is invariably coordinated by the imidazolic N7.…”

“…The Ru−Cp centroid distance is 1.865 Å that is larger than that observed in the starting complex [RuCpCl(PTA) 2 ] (Ru−Cp centroid = 1.844 Å) while the bond lengths between the ruthenium atom and both PTA phosphorus atoms (Ru−P1 = 2.266(1) Å; Ru−P2 = 2.272(1) Å) are different to those observed in the starting complex: respectively 2.258(3) Å and 2.247(3) Å. Surprisingly, the 8-MTT − anion is not coordinated by the purine-N7 atom, which was the expected coordination position as observed in most of the until now known crystal structures of purine-metal complexes, but by the purine-thio-ether-S atom. ,, Although there are several examples of bonds between Ru atoms and thioether S atoms, there are only three examples of ruthenium complexes containing nitrogen-thioether ligands, but none of them contains the ligand exclusively coordinated by sulfur. Additionally, there are no examples of complexes containing thioether-purines or other thioethers bearing NH groups, competing for coordination on the metal or stabilizing the S-thio-ether coordination by the formation of a chelate ring.…”

“…The 13 C{ 1 H} NMR spectrum is in agreement with the proposed composition: signals for N1-CH 3(8-TTH) and N3-CH 3(8-TTH) thiopurine methyl groups and for the Cp ligand are observed at 27.97 ppm, 30.19 ppm, and 79.49 ppm, respectively. The chemical shift for the C8−S carbon atom arises at 158.89 ppm, at higher field than that found for 8-TTH 2 in the same solvent (164.83 ppm). , Unfortunately the chemical shift of C8−S has not been reported for analogue complexes. The presence of coordinated PTA is also supported, in the 31 P{ 1 H} NMR spectrum, by a singlet at −22.97 ppm whose chemical shift is similar to that observed for the PTA ligand in [RuClCp(PTA) 2 ] (−23.6 ppm) …”

“…All reactions and manipulations were routinely performed under a dry nitrogen atmosphere by using standard Schlenk-tube techniques. The compounds PTA, [RuClCp(PTA) 2 ], and [RuClCp(PPh 3 )(PTA)] were prepared as described in the literature. ,, Ligands 8-thiotheophylline (8-TTH 2 ), 8-methylthiotheophylline (8-MTTH), 8-benzylthiotheophylline (8-BzTTH), bis( S -8-thiotheophylline)methane (MBTTH 2 ), 1,2-bis( S -8-thiotheophylline)ethane (EBTTH 2 ), 1,3-bis( S -8-thiotheophylline)propane (PBTTH 2 ) have been prepared following the procedure described by literature methods. , 1 H, 31 P{ 1 H} NMR, and 13 C{ 1 H} NMR spectra were recorded on a Bruker DRX300 spectrometer operating at 300.13 MHz ( 1 H), 121.49 MHz ( 31 P), and 75.47 MHz ( 13 C), respectively. Peak positions are relative to tetramethylsilane and were calibrated against the residual solvent resonance ( 1 H) or the deuterated solvent multiplet ( 13 C).…”

Synthesis and Structural Analysis of New Palladium(II) Thiosaccharinates with Triphenylphosphane or Diphosphanes

“…The Raman bands assignable to the stretching of the Pd–P bonds in complex 2 suggest a cis arrangement of the PPh 3 ligands. Several Pd II ‐thionate‐PPh 3 complexes with the phosphane ligands in cis positions have been reported by other research groups, with different coordination forms for the thionate ligands: chelating in [Pd(η 2 ‐N,S‐pym2S)(PPh 3 ) 2 ](ClO 4 ) 9e or [Pd(η 2 ‐N,S‐py2S)(Cl)(PPh 3 )] 9e, 9g; bridging in [Pd(μ 2 ‐N,S‐py2S)(Cl)(PPh 3 )] 2 9d.…”