Comparison of (triphenylphosphine)ruthenium complexes containing the 2,2′:6′,2′′-terpyridine (trpy) and 4,4′,4′′-tri- t-butyl-2,2′:6′,2′′-terpyridine (trpy ) ligands

• Published in: Inorganica Chimica Acta 2003-11, Vol.355, p.103-115
• Main Authors: Billings, Susan B, Mock, Michael T, Wiacek, Kevin, Turner, Melinda B, Kassel, W.Scott, Takeuchi, Kenneth J, Rheingold, Arnold L, Boyko, Walter J, Bessel, Carol A
• Format: Article
• Language: English
• Subjects: Crystal structures; NMR spectroscopy; Ruthenium; Terpyridine complexes
• ISSN: 0020-1693; 1873-3255
• DOI: 10.1016/S0020-1693(03)00300-1

A comparison of (triphenylphosphine)ruthenium(II) complexes containing the 2,2′:6′,2′′-terpyridine (trpy) and 4,4′,4′′-tri- t-butyl-2,2′:6′,2′′-terpyridine (trpy *) ligands was conducted. Electronic spectra and electrochemical data readily differentiated the trans- and cis-[RuCl 2(trpy or trpy *)(PPh 3)] complexes. 1H, 13C and 31P NMR assignments were made for each of the isomers as well as the trans-[RuCl(trpy *)(PPh 3) 2](PF 6) complex. Notably, the 31P chemical shift differences between the trans- and cis-[RuCl 2(trpy *)(PPh 3)] complexes were not dramatic and the 1H NMR spectra were found to be the best way for determining the position of the triphenylphosphine ligand relative to the terpyridyl ligand. X-ray crystal structure analyses confirmed the structures of the cis-[RuCl 2(trpy *)(PPh 3)] and trans-[RuCl(trpy *)(PPh 3) 2]PF 6 complexes. Similar π-stacking interactions occurred between the phenyl rings and the trpy * ligand in both complexes. A comparison of (triphenylphosphine)ruthenium(II) complexes containing the 2,2′:6′,2′′-terpyridine (trpy) and 4,4′,4′′-tri- t-butyl-2,2′:6′,2′′-terpyridine (trpy *) ligands was conducted. Electronic and NMR spectroscopy and electrochemical data were used to characterize the complexes. X-ray crystal structure analyses confirmed the structures of the cis-[RuCl 2(trpy *)(PPh 3)] and trans-[RuCl(trpy *)(PPh 3) 2]PF 6 complexes.