331823-25-7Relevant academic research and scientific papers
Synthesis, characterisation and coordination chemistry of novel chiral N,N-dialkyl-N′-menthyloxycarbonylthioureas. Crystal and molecular structures of N,Ndiethyl-Ar'-(-)-(3/?)-menthyloxycarbonylthiourea and m-(S,S)-[Pt(L)CI(DMSO)] [where HL = N-(+)(3JR)-menthyloxycarbonyl-A'-morpholinothiourea or W-benzoylAr',W-diethylthiourea]
Sacht, Cheryl,Datt, Michael S.,Otto, Stcfanus,Roodt, Andreas
, p. 4579 - 4586 (2000)
The novel ligands N,N-diethyl-N-(-)-(3fl)-menthyloxycarbonylthiourea (HL3), N,N-dklhyl-N'-(+)-(3R)-menthyoxycarbonylthiourea (HL4), AH-HS/-menthyloxycarbonyl-N'-morpholinothiourea (HL5) and N-(+)-(3R)menthyloxycarbonyl-W-morpholinothiourea (HL6) have been prepared and characterised. The molecular structure of HL3 has been confirmed by X-ray crystallography. The reaction of these Ar,Ar-disubstituted-Ar'-menthyloxycarbonylthiourea ligands with m-[PtQ2(DMSO)J in the presence of sodium acetate yields geometric isomers of the resultant (Pt(L)Cl(DMSO)] complexes, that is the DMSO is sulfur bonded to the platinum in either a cw-(S,S) or trans-(S,S) arrangement with respect to the sulfur donor atom of the chelated ligand. This is in contrast to the complexation reaction of c-[PtCI2(DMSO)2] with A'-benzoyl-AN'-diethylthiourea (HL1) or W-benzoyl-A morpholinothiourea (HL2) which yields only one [Pt(L)Cl(DMSO)] complex in which the DMSO is in a ra-(S,S) arrangement with respect to the sulfur donor atom of the chelated ligand. The molecular structures of c/s-(S,S)(Pt(L)Cl(DMSO)], where L = (L')- or (L6)-, have been determined by X-ray crystallography. The difference in the coordination chemistry of the acylthiourea and alkoxycarbonylthiourea ligands has been examined further by treating the [Pt(L)Cl(DMSO)] complexes with PPh3 to give the corresponding mono- and bis-(phosphine) complexes, [Pt(L)Cl(PPhj)] and [Pt(L)(PPh3)2] The 3IP NMR studies of these complexes reveal that the alkoxycarbonylthiourea ligands bind less strongly than the acylthiourea ligands, which is consistent with the crystallographic studies. The weaker binding properties of the alkoxycarbonylthiourea ligands might be a possible explanation for the observed geometric isomerisation of the complexes and that the mechanism could involve a chelate ring opening step. The Royal Society of Chemistry 2000.
