340756-01-6Relevant academic research and scientific papers
Synthesis of highly ethynylated mono and dinuclear Pt(II) tethers bearing the 4,4′-bis(ethynyl)biphenyl (debp) unit as central core
Russo,Lo Sterzo,Franceschini,Biagini,Furlani
, p. 49 - 61 (2001)
Mono and bisubstituted bis(ethynyl)biphenyl Pt(II) complexes, i.e. trans-[(R-CC-)Pt(PPh3)2(-CC-p-C6H 4-p-C6H4-CC-H)], R=p-NO2C6H4 (3b), (η5-C5H5)Fe(η5-C 5H4) (3c), and trans-[(R-CC-)Pt(PPh3)2(-CC-p-C6H 4-p-C6H4-CC-)Pt(PPh3) 2(-CC-R)], R=C6H5 (4a), p-NO2C6H4 (4b), (η5-C5H5)Fe(η5-C 5H4) (4c), have been synthesized by the dehydrohalogenation reaction from the appropriate Pt monochloro acetylides trans-[(R-CC-)Pt(PPh3)2Cl], R=C6H5 (1a), R=p-NO2C6H4 (1b), R=(η5-C5H4)Fe(η5-C 5H5) (1c) and HCC-p-C6H5-p-C6H5-CCH, (4,4′-bis-ethynylbiphenyl), (DEBP) (2). In order to make possible a direct evaluation of the role of Pt centers on the properties of these highly ethynylated complexes, the corresponding species without Pt were prepared, i.e. C6H5-CC-CC-C6H4-C6H 4-CC-CC-C6H5, (4,4′-(bis-phenylethynyl)-diethynylbiphenyl) (7), and (η5-C5H5)Fe(η5-C 5H4)-(CC-CC-C6H4-C6H 4-CC-CC)-(η5-C5H4)Fe(η 5-C5H5), (4,4′-(bis-ferrocenylethynyl)-diethynylbiphenyl) (8). Preparation of the latter compounds was only achieved by the use of the palladium catalyzed Stille coupling reaction, since the dehydrohalogenation route afforded only homocoupled and polymeric products. The electron-donor or electron-withdrawing ligands coordinated to Pt were chosen for the purpose of tuning the optical properties of the complexes through the different charge distribution along the π-electron conjugation. Characteristic spectroscopic features (UV-vis, FT-IR and NMR) of these complexes are discussed.
