Protonation sites in thiolato iron carbonylates: evidence for an arrested Fe(RS-H) oxidative addition

Methylation sites in tris(μ-thiolato)dimolybdenum(III) complexes

“…Reactions of [Mo 2 Cp 2 (l-SMe) 3 alkylating agent methyl triflate (Scheme 1). Exposure of the complexes with L = CNxyl (1b), CNBu t (1c) or NCMe (1d) to a large excess of methyl triflate resulted in methylation of a thiolate ligand and formation of the dicationic thioether derivatives 4b-4d.…”

“…The electronic properties of terminal ligands L in [Mo 2 Cp 2 (l-SMe) 3 L 2 ](BF 4 )(1) control the nucleophilicity of the lone pairs of thiolate-S atoms and hence the formation of thioether derivatives when 1 reacts with a methylating agent. When L = CO the strong p-acidity of carbonyl diminishes the donor power of the l-thiolato-S atoms of 1 and stops their reaction with methyl triflate, whereas this reaction occurs if L is any of the weaker p-acids CNBu t , NCMe or CNxyl.…”

“…Solvents were deoxygenated and dried according to standard procedures. The starting materials [Mo 2 Cp 2 (l-SMe) 3 (3) [5] were prepared as described previously. Elemental analyses were obtained from either the Service de Microanalyse I.C.S.N., Gif sur Yvette (France), or the Centre de Microanalyses du CNRS, Vernaison (France).…”

“…However, it remains to be seen how methylation reactions depend on: (i) the electronic properties of ancillary ligands, L, and (ii) the number and type (thiolate, sulfide or disulfide) of bridging S-donor ligands in {MoL 2 (l-SR/-S/-SS) n }complexes. Since alkylation reactions of transition metal complexes with three bridging S-donors have not previously been explored, we now consider how the characteristics of the ancillary ligands L influence the methylation reactions of the cationic tris(l-thiolato)-molybdenum derivatives [Mo 2 -Cp 2 (l-SMe) 3 L 2 ](BF 4 ) (L = CO (1a), CNxyl (1b), CNBu t (1c) and NCMe (1d) [4a,4b,4c,4d]. Also described are analogous reactions of the two neutral tris(l-thiolato) derivatives [Mo 2 Cp 2 (l-SMe) 3 (CNBu t )(CN)] (2) [4c] and [Mo 2 Cp 2 (l-SMe) 3 {l-g 1 -N=C(CH 3 )CH 2 CN}] (3) [5] which possess additional potential sites for attack by electrophiles.…”

Reversible Protonation of a Thiolate Ligand in an [Fe]‐Hydrogenase Model Complex

“…In synthetic chemistry, thiolate ligands acting as proton acceptors are well-known. [34,35] In [NiFe]-hydrogenase, a thiolate ligand is proposed as the internal base that promotes heterolytic H 2 splitting. [36] [28] If NEt 3 was added into the resulting solution, the starting compound was reformed.…”