Oxidative addition chemistry of tetrathiocines: synthesis, structures and properties of group 10 dithiolate complexes

Abstract

Oxidative addition of the electron-rich tetra-methoxy-dibenzo-1,2,5,6-tetrathiocine [(MeO)2C6H2S2]2 to zero-valent group 10 transition metal complexes in the presence of diphenylphosphinoethane (dppe) affords the corresponding dithiolate complexes, [(DMOBD)M(dppe)] (DMOBD = dimethoxybenzenedithiolato, (MeO)2C6H2S2(2-); M = Ni, Pd, Pt) in high yield which were characterized by single crystal X-ray diffraction. Whereas the Pd and Pt complexes exhibit two quasi-reversible 1e(-) oxidation processes, the nickel species undergoes a quasi-reversible 1e(-) reduction.

Oxidative addition of bis-(dimethoxybenzo)-1,2,5,6-tetrathiocins to Pt(PPh3)4: Synthesis and structures of mono- and di-metallic platinum dithiolate complexes, (dmobdt)Pt(PPh3)2 and [(dmobdt)Pt(PPh3)]2

“…The Pt-S bond lengths (2.3005 (18) and 2.3136(19) Å) and S-Pt-S bond angle (88.49(6)°) are similar to those found in (dmobdt)Pt(dppe) (2.3042(7) Å and 88.46(4)°). Conversely replacing the dppe ligand by two PPh 3 units leads to a lengthening of the Pt-P bond lengths (2.2914 (19) and 2.3096(19) Å) and an opening up of the P-Pt-P bond angle (95.55 (7)°) compared to (dmobdt)Pt(dppe) where the Pt-P bond length was 2.2552(7) and the corresponding bond angle is 85.31(4)° [ 18]. Both the increase in Pt-P bond length and increase in bond angle can be viewed as manifestations of the steric strain at the Pt(II) centre induced by the PPh 3 group (Tolman cone angle of 145°) [24].…”

“…Previously we found that 1 undergoes oxidative addition to zero-valent group 10 metals under microwave irradiation in the presence of the chelate phosphine dpihenylphosphino-ethane (dppe) to form (dmobdt)M(dppe) [M = Ni, Pd, Pt, dmobdt 2À = 3,4-dimethoxybenzene-1,2-dithiolate] [18]. Notably under microwave conditions the reactions were complete within 45 min affording recovered yields after recrystalisation in the range 77-89%.…”

“…Previously we found that bis-(dimethoxy-benzo)-1,2,5,6-tetrathiocine (1) undergoes oxidative addition to zero-valent group 10 metals under microwave irradiation in the presence of the chelate phosphine diphenylphosphino-ethane (dppe) to form (dmobdt)M (dppe) [M = Ni, Pd, Pt, dmobdt 2À = 3,4-dimethoxybenzene-1,2-dithiolate] [18] (Eq. (1)).…”

PdII(P‐P) Derivatives of o‐Quinone Annulated with Dithiete Cycle: Electrochemical Properties and Coordination Regioisomerism

“…The usage of tris(dibenzylideneacetone)dipalladium (Pd 2 dba 3 ) species in presence of free phosphine in the solution allows to avoid such synthetic complications. The procedure has been recently described by Rawson et al [ 15 ] for tetrathiocines and was adapted for preparation of complexes 4 and 5 . NMR monitoring confirms high effectivity of this approach: dithiolene and phosphine ligands almost entirely displace dba from the coordination sphere of Pd.…”

Synthesis of bis(trithio)phosphines by oxidative transfer of phosphorus(i)

“…These molecules have proven successful in regard to oxidative addition reactions with various late transition metals. [39][40][41][42] In this context, we suspected that these soft donors would be excellent candidates for oxidative addition reactions to the phosphorus(I) fragment in [P I dppe][Br].…”