Assessment of the. pi. -acceptor capability of selected ligands based on the photoelectron spectra of ruthenium ammine complexes

Journal Article · Wed Jul 29 00:00:00 EDT 1987 · Inorg. Chem.; (United States)

DOI:https://doi.org/10.1021/ic00262a021· OSTI ID:5648539

Shepherd, R E; Proctor, A; Henderson, W W; Myser, T K

ESCA spectra have been recorded for a series of Ru/sup II/ and Ru/sup III/ ammine complexes of general formula ((NH/sub 3/)/sub 5/RuL)X/sub n/ (X/sup -/ = PF/sub 6//sup -/, Cl/sup -/). Binding energy regions of the C/sub 1s/, Ru/sub 3d3/s/, and Ru/sub 3d5/s/, and Ru/sub 3p3/2/ photopeaks were studied. Binding energies were determined by using nonlinear-least-squares curve fitting. ..delta.. equal to the binding energy difference for (C/sub 1s/ - Ru/sub 3d5/2/) has been used to assign a fractional increase in charge at the Ru/sup II/ center when L = a series of ..pi..-acceptor ligands: N-methylpyrazinium (CH/sub 3/pz/sup +/), CO dimethyl acetylenedicarboxylate ester (dmad), CO, pyrazine (pz), pyridine (py), and CH/sub 3/CN. Authentic Ru/sup II/ and Ru/sup III/ oxidation states were assumed for (Ru(en)/sub 3/)ZnCl/sub 4/, ..delta.. = 5.1 eV, and (Ru(NH/sub 3/)/sub 6/)Cl/sub 3/, ..delta.. = 2.5 eV, respectively. The ..pi..-acceptor order and effective Ru oxidation state were determined to be as follows: CH/sub 3/pz/sup +/, 3.01 > CO, 2.88 > dmad, 2.73 > pz, 2.51 > CH/sub 3/CN, 2.31 > py, 2.20. ..delta.. was also found to be linear in the value of E/sub 1/2/ for the (NH/sub 3/)/sub 5/RuL/sup 3+/2+/ couple. ..pi..-Donor ligands exhibit little influence on ..delta.. for Ru/sup III/ derivatives; ..delta.. = 2.4 +/- 0.1 eV for 3,5-dimethylpyrazole, 4-(dimethylamino)pyridine, and 4-aminopyridine.

• Research Organization: Univ. of Pittsburgh, PA
• OSTI ID: 5648539
• Journal Information: Inorg. Chem.; (United States), Vol. 26:15
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
AMMINES
MOLECULAR STRUCTURE
RUTHENIUM COMPLEXES
BINDING ENERGY
EXPERIMENTAL DATA
LIGANDS
PHOTOELECTRON SPECTROSCOPY
COMPLEXES
DATA
ELECTRON SPECTROSCOPY
ENERGY
INFORMATION
NUMERICAL DATA
SPECTROSCOPY
TRANSITION ELEMENT COMPLEXES
400201* - Chemical & Physicochemical Properties