76767-38-9Relevant academic research and scientific papers
A comparative study of cyclometallated palladium(II) compounds with terdentate [C,N,S] pincer ligands - Crystal and molecular structure of [Pd{4-MeC6H3C(Me)=NNC(=S)NHMe}(PPh3)] and [Pd{4-MeOC6H3C(H)=N[2- (SMe)C6H4]}(Cl)]
Amoedo, Adriana,Grana, Maria,Martinez, Javier,Pereira, Teresa,Lopez-Torres, Margarita,Fernandez, Alberto,Fernandez, Jesus J.,Vila, Jose M.
, p. 613 - 620 (2007/10/03)
Treatment of the thiosemicarbazone ligands 4-MeC6H4C(Me)=NN(H)C(=S)NHMe (a), 4-MeC6H4C(Me)=NN(H)C(=S)NHEt (b), and 4-MeC6H4C(Me)=NN(H)C(= S)NHPh (c) with K2[PdCl4] produced the tetranuclear palladium(II) compounds [Pd{4-MeC6H3C(Me)=NNC(=S)-NHMe}]4 (1a), [Pd{4-MeC6H3C(Me)=NNC(=S)NHEt}]4 (1b), and [Pd{4-MeC6H3C(Me)=NNC(=S)NHPh}]4 (1c) with deprotonation of the NH group. Treatment of thiosemicarbazones 4-MeOC6H4C(H)=NN(Me)C(=S)NH2 (d) and 3-Me-OC6H4C(H)=NN(Me)C(=S)NH2 (e) with K2[PdCl4] gave the mononuclear palladium(II) compounds [Pd{4-MeOC6H3-C(H)=NN(Me)C(=S)NH2}(C1)] (1d) and [Pd{3-MeOC6H3-C(H)=NN(Me)C(=S)NH2}(C1)] (1e). Treatment of the Schiff base 4-MeOC6H4C(H)=N[2-(SMe)C5H4] (f) with Li2[PdCl4] afforded [Pd{4-MeOC6H3C(H)=N[2- (SMe)C6H4]}(Cl)] (1f). All the ligands are terdentate through the [C,N,S] atoms and the Pd-S bond formed is sufficiently strong to tolerate treatment with nucleophiles without bond cleavage. Treatment of 1a, 1b, and 1c with triphenylphosphane gave the mononuclear species 2a, 2b, and 2c, which upon treatment with hydrochloric acid resulted in the 1f electrolytes 3a, 3b, and 3c, with NH and C=S groups. Coordination of PPh3 to Pd in 1:1 was achieved by treatment of the compound with sodium perchlorate, followed by the nucleophile in a 1:1 molar ratio, to yield 2f. The crystal structures of compounds 2a and 1f are described.
Ring-chain tautomerism of N-substituted thiosemicarbazones
Zelenin,Kuznetsova,Alekseyev,Terentyev,Torocheshnikov,Ovcharenko
, p. 1257 - 1270 (2007/10/02)
The condensation products from 4,4-dimethyl- and 2,4,4-trimethylthiosemicarbazides and aldehydes or ketones, as well as those from 2-methyl- and 2,4-disubstituted thiosemicarbazides and aldehydes have the thiosemicarbazone structure, while ketones react with 2-methyl- or 2,4-dialkylthiosemicarbazides to form 1,2,4- triazolidine- 3-thiones. Both thiosemicarbazones and 1,2,4- triazolidine- 3-thiones in trifluoroacetic acid solution yield 1,3,4-thiadiazolidine-2-iminium salts. Their deprotonation by pyridine leads to thiosemicarbazones, including otherwise inaccessible 2-methyl- and 2,4-disubstituted ketone thiosemicarbazones. The mass-spectrometric investigation of these compounds also suggests presence of their tautomers in the gas phase.
