Thioethers bridging ligands

Emslie also reported the ability of the related rigid phosphine-thioether-borane ligand 32 (referred to as PSB) to engage in bridging P-M-Cl-B interaction upon coordination to rhodium and palladium precursors (Scheme 52).7, 76... 

A new oxyhemocyanin molluskan (octopus) protein x-ray structure has been reported [188a]. The active-site is very similar to that observed for the horseshoe crab structure one of the six histidine ligands is involved in a thioether bridge, i.e., to a nearby cysteine. 

The cyclic polythioether complex [W(CO)4L] (L = 2,5,8,ll-tetrathia[12](2,5)thiophenophane was prepared by UV irradiation of [W(CO)6] in the presence of the ligand in thf. Variable-temperature H NMR studies showed that this species was fluxional, and the derived molecular structure indicated k -L-S S coordination (17). The thioether-bridged complexes [ W(CO)4)2T] (18), where L is the hexakis(alkylsulfanylmethyl)benzene, C6(CH2SR)6 (R = C5H11, Pr ) were obtained by reaction of [W(CO)4(NCMe)2] with the appropriate thioether. Reaction of [W(CO)4(tmpa)] (tmpa = V,iV,iV, iV -tetramethyl-l,3-propanediamine) with 1,5-diselenacyclooctane ([8]aneSe2) gave the cis-disubstituted produce [W(CO)4 [8]aneSe2 ]. 

Bridging coordination of M—X bonds (M=Rh, Pd, Pt X=C1, Br, I) with a tridentate phosphine-thioether-borane ligand has been extensively investigated by Emslie. Close inspection of the [Rh(CO)X] complexes 28 (Figure 16) indicated that the boron center interacts more strongly with Cl and Br than with I. ... 

Ni11 complexes of various amine/thiophenolate ligands have been investigated (for Ni complexes of ortho-aminothiophenol see Section 6.3.4.9.2(iv)). Thiophenolate is expected to exhibit decreased bridging tendency compared to aliphatic thiolates, but complexes (466) and (467) still consist of two pseudo-octahedral NiL fragments bridged via thiolate donors. In contrast to the parent complex (466), the thiolate and thioether donors in (467) coordinate cis to the Ni center... 

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