Hydrides thiolate complexes

Although thiol and hydride/thiolate complexes are known, there are few studies which show that the hydrogen can move between metal and sulfur [35-38]. The transfer of a proton from sulfur to metal has been proposed before. For example, the so-called oxidative-addition of RSH to [IrCl(CO)(PPh3)2] has been suggested to involve a three-centre, Ir-H-SR transition state in which the lengthening of the S-H bond is synchronous with the binding of these two atoms to the iridium centre [39]. More recently [40] an agostic Os—H-S interaction has... 

Evidence for M---H-S interaction is less clear, but protonation of [Fe(SMe)-(CO)3(PEt3)] at -80°C gives a species with an abnormal high-field NMR resonance for the S-H proton near 5 — 8. This resonance decays irreversibly on wanning, and an isomeric mixture of hydride-thiolate complexes results. Low-temperature (-57°C) IR spectra of the initial protonation product in Eq. (13.13) shows a Vco band at 1870 cm consistent with an Fe" rather than an Fc" complex. On warming, the band converts to others that match those observed for the hydride-... 

P-Hydrogen eliminations and p-aryl eliminations from alkoxo and amido complexes are also known. Such eliminations have been shown to occur by migratory de-insertion pathways, as well as alternative p-hydride abstraction mechanisms. P-Hydrogen eliminations from metal-silyl complexes are rare because the silicon-carbon double bond in the product is weak. For similar reasons, p-hydrogen eliminations from metal-thiolate complexes are rare. 

According to this model the iron-hydride bond is cleaved upon illumination and the hydride, together with the proton, leaves the complex. This would lead to re-establishment of the nickel thiolate bond which was weakened in the former state, explaining the changes in the EPR spectrum observed after illumination (Pig. 7.16-III). After a flip of the electronic z-axis the selenium could in this state interact with the unpaired electron in an orbital with d -y2 character. To get EPR-active, CO-treated... 

Reaction of Resin-Bound Iron Complex (54) with Alkyl Mercaptans, Thiophenols, and Phenols (Fig. 9)31. Sodium thiolates are prepared analogously to the alkoxides from thiol and sodium hydride, except that dry DMF is used as a solvent. The substitution on the polymer-bound arene (54) is performed at 70° in DMF within 16 h. The resin is filtered and washed with DMF (2 x 50 ml), MeOH (2 x 50 ml), H20 (2 x 50 ml), MeOH (2 x 50 ml), and CH2CI2 (3 x 50 ml) and then dried in vacuo at 40° to yield a red resin. 

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