91602-67-4Relevant academic research and scientific papers
Synthesis and NMR characterization of the novel mixed-ligand Pt(II) complexes cis- and trans-Pt(Ypy)(pyrimidine)Cl2 and trans,trans-Cl2(Ypy)Pt(μ-pyrimidine)Pt(Ypy)Cl2 (Ypy = pyridine derivative)
Rochon, Fernande D.,Fakhfakh, Majd
, p. 1455 - 1466 (2009/08/08)
Mixed-ligand complexes of the type cis- and trans-Pt(Ypy)(pm)Cl2 where Ypy = pyridine derivative and pm = pyrimidine were synthesized and characterized by IR spectroscopy and by multinuclear (195Pt, 1H and 13C) magnetic resonance spectroscopy. The cis compounds were prepared from the reaction of K[Pt(Ypy)Cl3] with pyrimidine (1:1 proportion) in water, while most of the trans isomers were synthesized from the isomerization of the cis compounds. The cis isomers could not be isolated with the Ypy ligands containing two -CH3 groups in ortho positions. When the aqueous reaction of K[Pt(Ypy)Cl3] with pyrimidine was performed in a Pt:pm ratio = 2:1, the pyrimidine-bridged dinuclear species were formed. Only the most stable trans-trans isomers could be isolated pure. In IR spectroscopy, the cis monomers showed two ν(Pt-Cl) bands, while the trans monomers and dimers showed only one ν(Pt-Cl) band. The 195Pt NMR signals of the cis monomers were found at slightly higher fields than those of the corresponding trans isomers. The δ(195Pt) of the dimers were found close to those of the trans monomers. The NMR results were interpreted in relation to the solvent effect, which seems important in these complexes. The coupling constants J(195Pt-1H) and J(195Pt-13C) are larger in the cis geometry. The crystal structures of the compounds cis-Pt(2,4-lut)(pm)Cl2, trans-Pt(2,6-lut)(pm)Cl2 and trans,trans-Cl2(2,6-lut)Pt(μ-pm)Pt(Ypy)Cl2 were studied by X-ray diffraction methods and the results have confirmed the configurations suggested by IR and NMR spectroscopies.
Multinuclear NMR study and crystal structures of complexes of the types cis- and trans-Pt(Ypy)2X2, where Ypy=pyridine derivative and X=Cl and I
Tessier, Christian,Rochon, Fernande D.
, p. 25 - 38 (2008/10/08)
Complexes of the types cis- and trans-Pt(Ypy)2X2 where Ypy is a methyl derivative of pyridine and X=Cl or I were studied by spectroscopic methods, especially by multinuclear NMR spectroscopy. In 195Pt MNR, the cis-dichloro compounds were observed between -1998 and -2021 ppm in CDCl3, while the trans compounds were found at slightly lower field, between -1948 and -1973 ppm. The diiodo species were observed at much higher field, between -3199 and -3288 ppm for the cis isomers and between -3122 and -3264 ppm for the trans isomers. In 1H NMR, the 3J(195Pt-1H) coupling constants are larger for the cis compounds (about 42 ppm) than for the trans isomers (about 33 ppm). In 13C NMR, the values of 3J(195Pt-13C) were also found to be larger for the cis complexes. There seems to be a slight dependence of the pKa values of the protonated ligands on the δ(Pt) chemical shifts. The presence of π-bonding between Pt and the pyridine ligands do not seem very important. The crystal structures of three dichloro and five diiodo complexes were determined, in an attempt to obtain information on the trans influence of the three ligands. The results have shown that the iodo ligand has the greatest trans influence. Chloro and pyridine ligands seem to have similar trans influence, although, the chloro ligand seems to have a slightly larger influence than pyridine derivatives. One structure, trans-Pt(2-pic)2I2, has shown a syn conformation of the two 2-picoline ligands.
Nucleophilic displacement of the chelating bis(sulfoxide) from cis-[meso-1,2-bis(phenylsulfinyl)ethane]dichloroplatinum(II) and cis-[rac-1,2-bis(phenylsulfinyl)ethane]dichloroplatinum(II)
Cattalini, Lucio,Marangoni, Giampaolo,Michelon, Gianni,Paolucci, Gino,Tobe, Martin L.
, p. 71 - 75 (2008/10/08)
The kinetics of ring opening, by amines in 1,2-dimethoxyethane, have been measured for two bis(sulfoxide)-platinum(II) isomers. The results make possible a discussion of the differences between the two isomers, in comparison with other platinum(II) complexes, in terms of absolute reactivity, nucleophilic discrimination, and steric retardation effects.
