85848-64-2Relevant academic research and scientific papers
Synthesis and Structure of η4-Enone Complexes of Ruthenium(0)
Marcuzzi, Alessandro,Linden, Anthony,Philipsborn, Wolfgang von
, p. 976 - 987 (2007/10/02)
A variety of 4-enone)> complexes (L = phosphines, phosphites, and arsines, enone = (E)-4-phenylbut-3-en-2-one) have been synthesized. 1H, 13C-, and 31P-NMR spectra are reported and the X-ray structures of two Ru complexes with L = Ph3P (7), Et3P (10) and one Fe complex with L = Ph3P (14) are presented.All three compounds crystallize in the same monoclinic space group P21/n with a = 10.575(2) Angstroem, b = 9.213(2) Angstroem, and c = 27,608(5) Angstroem, β = 100,04(2) deg, Z = 4 for 7, a = 10,276(3) Angstroem, b = 12,935(3) Angstroem, and c = 14,854(2) Angstroem, β = 96,96(2) deg, Z = 4 for 10, and a = 10,492(2) Angstroem, b = 9,232(3) Angstroem, and c = 27,129(3) Angstroem, β = 98,67(2) deg, Z = 4 for 14.The structures of the Ru complexes are compared with the Fe analogues.In the case of M = Ru and L = (EtO)3P, (MeO)3P, and (i-PrO)3P (9, 11, and 13, respectively) stereoisomers could be detected by 31P-NMR at room temperature, which arise from rotation at the coordinated metal centre.
Photofragmentation Kinetics of Some Triruthenium Carbonyl Clusters
Brodie, Nacy M. J.,Huq, Rokeya,Malito, John,Markiewicz, Stan,Poe, Anthony J.,Sekhar, Vasu C.
, p. 1933 - 1940 (2007/10/02)
The photokinetics of fragmentation reactions of with L=PPh3, P(OPh)3, AsPh3, CO, 1-octene, and methyl acrylate in a variety of solvents have been studied.Quantum yields increase to limiting values at high but the limiting values vary significantly with the nature of L.The low efficiency of photochlorination in chlorocarbon solvents, the absence of inhibition by CO of reactions with L=PPh3, and the absence of appropriate effects of varying incident light intersity all suggest that the first kinetically significant product is a non-radical reactive isomer of .This can revert to or react with L to form which itself can revert to or undergo fragmentation.The former choice governs the rate of increase with to a limiting quantum yield whereas the latter choice governs the dependence of the values of the limiting quantum yield on the nature of L.This scheme is also applicable to photoreactions of and the quantitative behaviour of the two clusters is not significantly different.Only lower limits for quantum yields for formation of the reactive isomers can be deduced from the data and it remains possible that the primary photophysical process is the formation of a very short-lived diradical by homolysis of a metal-metal bond.Photokinetic studies of reactions of with L (L=PPh3 or PBun3) are also reported.
Axial-equatorial isomerism in the complexes M(CO)4(L) (M = Fe, Ru, Os; L = group 15 ligand). Crystal structures of ax-Ru(CO)4(AsPh3), ax-Ru(CO)4(SbMe3), and eq-Os(CO)4(SbPh3)
Martin, Lillian R.,Einstein, Frederick W. B.,Pomeroy, Roland K.
, p. 2777 - 2785 (2008/10/08)
The compounds M(CO)4(L) (M = Fe, Ru, Os; L = EPh3, E = P, As, Sb; L = PMe3, P(OCH2)3CMe. M = Ru, Os; L = SbMe3) have been synthesized from L and M(CO)5. The crystal structures of ax-Ru(CO)4(AsPh3), ax-Ru(CO)4(SbMe3), and eq-Os-(CO)4(SbPh3) have been determined by X-ray crystsllography. ax-Ru(CO)4(AsPh3): space group P1; a = 10.605 (3), b = 11.068 (4), c = 9.979 (3) ?; α = 113.57 (3), β = 93.14 (3), γ = 91.47 (3)°; Z = 2; R1 = 0.020, R2 = 0.021 (1650 observed reflections); AsPh3 in an axial position of the trigonal-bipyramidal coordination sphere, Ru-As = 2.461 (1) ?. ax-Ru(CO)4(SbMe3): space group R3, a = 10.378 (1), c = 9.632 (1) ?; Z =_3; R1 = 0.023, R2 = 0.030 (523 observed reflections); SbMe3 axial, Ru-Sb = 2.619 (1) ?. eq-Os(CO)4(SbPh3): space group P1; a = 11.123 (2), b = 11.284 (4), c = 12.714 (4) ?; α = 129.29 (2), β = 102.35 (2), γ = 102.45 (2)°; Z = 2; R1 = 0.019, R2 = 0.021 (3115 observed reflections); SbPh3 equatorial, Os-Sb = 2.612 (2) ?. Infrared spectroscopy revealed that in solution many of the complexes exhibited axial - equatorial isomerism. The tendency to give the less common equatorial isomer was Ru > Os > > Fe, Sb > As > P, Ph > Me, and P(OCH2)3CMe > PMe3, PPh3. The order for the group 15 element was rationalized in terms of the σ-donor ability of the element: in agreement with theoretical predictions, weaker donors prefer the equatorial site. The π-bonding ability of the ligands may also be important in determining the other trends. Carbon-13 NMR spectra, which revealed the isomers were in rapid equilibrium in solution, were also recorded.
