TY - JOUR
T1 - Structure and reactivity of the zero-valent ruthenium complex Ru(1,2-bis(diphenylphosphino)ethane)(CO)3 and the dicationic ruthenium dimer [Ru2(1,2-bis(diphenylphosphino)ethane)2(CO) 6]2+
AU - Skoog, Steven J.
AU - Jorgenson, Amy L.
AU - Campbell, John P.
AU - Douskey, Michelle L.
AU - Munson, Eric
AU - Gladfelter, Wayne L.
N1 - Funding Information:
We thank Ken Caulton for helpful conversations. The research was supported by a grant from the National Science Foundation (CHE-9223433)
PY - 1998/4/20
Y1 - 1998/4/20
N2 - The structure of Ru(dppe)(CO)3 was characterized by single crystal X-ray diffraction [monoclinic crystal system, space group P21/n, a=12.2353(2) Å, b=16.0803(3) Å, c=14.2451(3) Å, β=111.109(1)°, V=2614.62(9) Å3, Z=4] and found to be intermediate between trigonal bipyramidal and square pyramidal. One electron oxidation of Ru(dppe)(CO)3 using [(η5-C5H5)2Fe][PF6] produced [Ru2(dppe)2(CO)6][PF6]2. The dicationic complex was fully characterized by solution spectroscopic methods and by single crystal X-ray diffraction [trigonal crystal system, space group P3121, a=20.566(2) Å, c=13.871(2) Å, V=5080.7(8) Å3, Z=3] and found to have a dimeric structure with two octahedral units sharing a common apex via a Ru(I)-Ru(I) single bond. One octahedral unit is rotated approximately 45° relative to the other, and the chelating phosphine ligand occupies sites cis and trans to the Ru(I)-Ru(I) bond. All of the carbonyl ligands were found to be terminal. The dimer was fluxional in solution and line-shape analysis of the 31P{1H} and 13C{1H} variable-temperature NMR spectra was used to investigate the exchange mechanism and evaluate the rate constants. The mechanism involved an intramolecular, two-site exchange involving pairwise bridging carbonyls and had activation parameters of 11.8±0.15 kcal mol-1 and -6.7±0.6 eu for ΔH‡ and ΔS‡ respectively. The dimer exhibited similar thermal and photochemical reactivity patterns; disproportionation occurred in CH3CN and halogen atom abstraction occurred in halogenated solvents.
AB - The structure of Ru(dppe)(CO)3 was characterized by single crystal X-ray diffraction [monoclinic crystal system, space group P21/n, a=12.2353(2) Å, b=16.0803(3) Å, c=14.2451(3) Å, β=111.109(1)°, V=2614.62(9) Å3, Z=4] and found to be intermediate between trigonal bipyramidal and square pyramidal. One electron oxidation of Ru(dppe)(CO)3 using [(η5-C5H5)2Fe][PF6] produced [Ru2(dppe)2(CO)6][PF6]2. The dicationic complex was fully characterized by solution spectroscopic methods and by single crystal X-ray diffraction [trigonal crystal system, space group P3121, a=20.566(2) Å, c=13.871(2) Å, V=5080.7(8) Å3, Z=3] and found to have a dimeric structure with two octahedral units sharing a common apex via a Ru(I)-Ru(I) single bond. One octahedral unit is rotated approximately 45° relative to the other, and the chelating phosphine ligand occupies sites cis and trans to the Ru(I)-Ru(I) bond. All of the carbonyl ligands were found to be terminal. The dimer was fluxional in solution and line-shape analysis of the 31P{1H} and 13C{1H} variable-temperature NMR spectra was used to investigate the exchange mechanism and evaluate the rate constants. The mechanism involved an intramolecular, two-site exchange involving pairwise bridging carbonyls and had activation parameters of 11.8±0.15 kcal mol-1 and -6.7±0.6 eu for ΔH‡ and ΔS‡ respectively. The dimer exhibited similar thermal and photochemical reactivity patterns; disproportionation occurred in CH3CN and halogen atom abstraction occurred in halogenated solvents.
KW - Carbonyl
KW - Crystal structure
KW - Dynamic NMR
KW - Metal-centered radicals
KW - Photochemistry
KW - Ruthenium
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U2 - 10.1016/S0022-328X(97)00731-6
DO - 10.1016/S0022-328X(97)00731-6
M3 - Article
AN - SCOPUS:0002645174
SN - 0022-328X
VL - 557
SP - 13
EP - 28
JO - Journal of Organometallic Chemistry
JF - Journal of Organometallic Chemistry
IS - 1
ER -