Article (Author postprint) (432 Kb) - Limited access to UNIGE
Other version: http://www.sciencedirect.com/science?_ob=MImg&_imagekey=B6TH8-3Y8WJ1D-X-S&_cdi=5276&_user=779890&_orig=browse&_coverD...
Potentiometric, spectrophotometric and ES–mass spectroscopic studies of the formation of binary and ternary species between Cu2, a pyrazole bridged N2S-bismacrocycle and exogenous ligands
|Published in||Polyhedron. 1998, vol. 17, no. 25-26, p. 4543-4551|
|Abstract||The protonation and stability constants of the binary Cu2 complexes with 1,1'-[(1H-pyrazole-3,5-diyl)bis(methylene)]bis(octahydro-1H-1,4-triazonine) were determined by potentiometric titrations at 25° and I=0.5 M (KNO3). The results show that a series of mononuclear [Cu(LHn)] (n=1, 0, −1, −2) and dinuclear species [Cu2(LHm)] (m=0, −1, −2, −3) are formed. Structures are proposed for them based on their absorption spectra and results previously obtained from X-ray diffraction studies. Complex [Cu2(LH−1)]3, in which the pyrazole bridging group is deprotonated, is especially interesting since it is able to bind exogenous ligands Z such as N3−, pyrazole and 1H,1'H-4,4'-methanediyl-bis-pyrazole (bispyr) to give ternary species [Cu2(LH−1)Z] and [[Cu2(LH−1)]2Z], the stabilities of which have been measured by spectrophotometric titrations. In the case of bispyr the existence of the tetranuclear complex [[Cu2(LH−1)]2(bispyr)]2 has been proven by ES–MS.|
|Keywords||Binary Cu2 complexes — 1 — 1'-[(1H-pyrazole-3 — 5-diyl)bis(methylene)]bis(octahydro-1H-1 — 4-triazonine)|
|WELLER, Harald, KADEN, Thomas A., HOPFGARTNER, Gerard. Potentiometric, spectrophotometric and ES–mass spectroscopic studies of the formation of binary and ternary species between Cu2, a pyrazole bridged N2S-bismacrocycle and exogenous ligands. In: Polyhedron, 1998, vol. 17, n° 25-26, p. 4543-4551. https://archive-ouverte.unige.ch/unige:2319|