108149-34-4Relevant academic research and scientific papers
Organosulfide group transfer reactions of transition-metal carbonyl radicals: Electronic and steric effects
Lee, Kang-Wook,Brown, Theodore L.
, p. 1852 - 1856 (2008/10/08)
Photochemical reactions of M2(CO)10 (M = Mn, Re) with RSSR (R = Me, Ph) or MeSSiMe3 in hexane at ambient temperature yield (μ-SR)2M2(CO)8 (70-85%) and [M(CO)3SR]4 (0-15%). The corresponding reaction of Re2(CO)8L2 almost quantitatively yields (μ-SR)2Re2(CO)6L2, and the reaction of Re2(CO)10 and [Me2NC(S)S]2 gives (η2-S2CNMe2)Re(CO)4. The initial product for each reaction is RSM(CO)4L (L = CO, PR3), formed by RS group transfer from RSSR to the ?M(CO)4L radical generated by photolysis. (μ-SR)2M2(CO)8 is in equilibrium with the 16-electron species RSM(CO)4 under photochemical conditions. Laser flash photolysis kinetics studies reveal the electronic and steric effects of L ligands in the Re(CO)4L? radical and the steric effect of the R group in RSSR on the group transfer rate constant. The relative rate constants for reactions of Re(CO)4PMe3? with various dialkyl disulfides decrease in the order methyl > n-butyl > sec-butyl > tert-butyl (630:280:36:1). The rate constants for group transfer for a series of Re(CO)4L? radicals fit a two-parameter free energy relationship wherein the electronic and the steric parameters of L are represented. The reaction is accelerated by increased electron donor capability of L and retarded by increased size of L.
