210820-27-2Relevant academic research and scientific papers
Organometallic complexes of platinum-group metals incorporating substituted guanidine dianion (triazatrimethylenemethane) ligands
Dinger, Maarten B.,Henderson, William,Nicholson, Brian K.
, p. 75 - 88 (1998)
Reactions of the platinum-group metal halide complexes [PtCl2(COD)] (COD=1,5-cyclo-octadiene), [Cp*RhCl2(PPh3)] (Cp=η5-C5Me5), [Cp*IrCl2(PPh3)], [(p-cymene)RuCl2(PPh3)] and [(p-cymene)OsCl2(PPh3)] with symmetrically trisubstituted (acetyl or phenyl) guanidines, mediated by silver(I) oxide, give complexes formally containing the triazatrimethylenemethane ligand. A full X-ray crystal structure determination is reported for the N,N′,N″-triphenylguanidine dianion complex [Pt{NPhC(=NPh)NPh}(COD)] 4a which shows the presence of a planar Pt-NR-C(=NR)-NR four-membered platinacycle. At room temperature (r.t.), the 1H- and 13C{1H}-NMR spectra of 4a yield a single set of COD CH and CH2 resonances. At 240 K however, two sets of resonances are observed, interpreted in terms of fluxionality of the C=N-Ph moiety. Attempted synthesis of the analogous platinum triacetylguanidine complex yields the new ureylene complex [Pt{NAcC(=O)NAc}(COD)], via a hydrolysis reaction. Starting with the osmium compound, both the guanidine complex [(p-cymene)Os{NAcC(=NAc)NAc}(PPh3)] 9 and the ureylene complex [(p-cymene)Os{NAcC(=O)NAc}(PPh3)] 10 were formed; similar results were obtained for the iridium system.
