15684-00-1Relevant articles and documents
Synthesis and Characterization of the Pentacarbonylmanganese(0) Radical, Mn(CO)5, in Low-Temperature Matrices
Church, Stephen P.,Poliakoff, Martyn,Timney, John A.,Turner, James J.
, p. 7515 - 7520 (1981)
Mn(CO)5 has been synthesized by UV photolysis of HMn(CO)5 in solid CO matrices at 10 - 20 K.The HCO radical is also produced.A combination of 13CO enrichment and IR spectroscopy shows that Mn(CO)5 has a square-pyramidal, C4v, structure with an axial-equatorial bond angle of 96 +/- 3 grad.Mn(CO)5 has a weak visible absorption (λmax = 798 nm), close to the absorption reported for Mn(CO)5 generated in ethanol solution by pulse radiolysis.Photolysis with plane-polarized UV light has been used to unravel some of the complexities in the IR spectrum and to show that the UV absorption of Mn(CO)5 in the region 300 - 340 nm has a transition moment of e symmetry.
Photophysical features of the M2(CO)10, M = Mn and Re, solution photochemistry
Sarakha,Ferraudi
, p. 4605 - 4607 (1999)
-
Rate constants for reactions of Cl abstraction from CCl4 by CCl3CH2 .CHR radicals and Br abstraction from CCl3CH2CHBrR (R = Bun, AcO, OCNC4H8, CN) by .
Gasanov
, p. 46 - 49 (2007/10/03)
The rate constants for reactions of Cl abstraction from CCl4 by CCl3CH2 .CHR radicals and Br abstraction from CCl3CH2CHBrR (R = Bun, AcO, OCNC4H8, CN) by s
Photochemical bond homolysis in a novel series of metal-metal bonded complexes Ru(E)(E′)(CO)2(iPr-DAB)
Aarnts, Maxim P.,Stufkens, Derk J.,Vlcek Jr., Antonin
, p. 37 - 46 (2008/10/08)
Photochemistry of the complexes trans,cis-Ru(E)(E′)(CO)2(iPr-DAB) (E = Cl, SnPh3, PbPh3, Mn(CO)5, Re(CO)5, Me; E′ (depending on E) = SnPh3, PbPh3, GePh3, Mn(CO)5, Re(CO)5) was found to be strongly dependent on the combination and characters of the axial ligands E and E′. Except for Ru(Cl)(SnPh3)(CO)2(iPr-DAB) and Ru(Cl)(PbPh3)(CO)2(iPr-DAB) which are nearly unreactive, one of the Ru-E/E′ bonds is split homolytically upon irradiation into the lowest-energy absorption band of the complex. For Ru(SnPh3)2(CO)2(iPr-DAB), this reaction occurs from a thermally equilibrated 3σπ* excited state with a rate constant of 2.3 × 105 s-1 and a temperature-dependent quantum yield (Ea = 1450 cm-1). The unselective Ru-Ge (60%) and Ru-Sn (40%) bond homolysis of Ru(SnPh3)(GePh3)(CO)2-(iPr-DAB) follows the same mechanism. On the other hand, bond homolysis is much faster (?108 s-1) for complexes which contain Ru-Me, Ru-Mn or Ru-Re bonds. Bond homolysis in these species is highly selective, since only Ru-Me, Ru-Mn and Ru-Re bond splitting was observed for Ru(Me)(SnPh3)(CO)2(iPr-DAB), Ru(SnPh3)(Mn(CO)5)(CO)2(iPr-DAB) and Ru(SnPh3)(Re(CO)5)(CO)2(iPr-DAB), respectively. The photoproduced [Ru(E)(CO)2(iPr-DAB)]· radicals were detected by time resolved UV-Vis spectroscopy on a timescale 10 ns-100 μs. The [Ru(SnPh3)(CO)2(iPr-DAB)]· radical was also characterised by EPR in the form of its adduct with PPh3. Depending on the solvent used, they either dimerise or abstract a chlorine atom from the solvent to produce Ru(Cl)(E)(CO)2(iPr-DAB).
