Transition metal complexes with wide-angle dithio-, diseleno- and ditelluroethers: properties and structural systematics

Abstract

The ligands o-C(6)H(4)(CH(2)EMe)(2) (E = S or Se) have been prepared and characterised spectroscopically. A systematic study of the coordination chemistry of these, together with the telluroether analogue, o-C(6)H(4)(CH(2)TeMe)(2), with late transition metal centers has been undertaken. The planar complexes [MCl(2){o-C(6)H(4)(CH(2)SMe)(2)}] and [M{o-C(6)H(4)(CH(2)EMe)(2)}(2)](PF(6))(2) (M = Pd or Pt; E = S or Se), the distorted octahedral [RhCl(2){o-C(6)H(4)(CH(2)EMe)(2)}(2)]Y (E = S or Se: Y = PF(6); E = Te: Y = Cl) and [RuCl(2){o-C(6)H(4)(CH(2)EMe)(2)}(2)] (E = S, Se or Te), the dithioether-bridged binuclear [{RuCl(2)(p-cymene)}(2){micro-o-C(6)H(4)(CH(2)SMe)(2)}] and the tetrahedral [M'{o-C(6)H(4)(CH(2)EMe)(2)}(2)]BF(4) (M' = Cu or Ag; E = S, Se or Te) have been obtained and characterised by IR and multinuclear NMR spectroscopy ((1)H, (63)Cu, (77)Se{(1)H}, (125)Te{(1)H} and (195)Pt), electrospray MS and microanalyses. Crystal structures of the parent o-C(6)H(4)(CH(2)SMe)(2) and seven complexes are described, which show three different stereoisomeric forms for the chelated ligands, as well as the first example of a bridging coordination mode in [{RuCl(2)(p-cymene)}(2){micro-o-C(6)H(4)(CH(2)SMe)(2)}]. These studies reveal the consequences of the sterically demanding o-xylyl backbone, which typically leads to unusually obtuse E-M-E chelate angles of approximately 100 degrees .

Synthesis and complexation of dichalcogenoethers with cyclopropyl backbones, (CH2EMe)2 (E=Se or Te)

“…The Me 2 Se formed is then quaternised to [Me 3 Se]I. A different selenonium derivative [C 17 H 19 Se] 2 [TiCl 6 ] was obtained from the reaction of o-C 6 H 4 (CH 2 SeMe) 2 with TiCl 4 [22], but the diselenoether ligand has produced a wide range of complexes with later transition metals in which it functions as a chelating bidentate as expected [23]. In contrast, the ditelluroether o-C 6 H 4 (CH 2 TeMe) 2 quaternises ''normally" to form o-C 6 H 4 (CH 2 TeMe 2 I) 2 which has a dimer structure composed of a Te 4 I 4 cubane core [24].…”

Tungsten(VI) and Molybdenum(VI) Complexes with Soft Thioether Ligand Coordination – Synthesis, Spectroscopic and Structural Studies

“…This is the first Mo VI complex incorporating other than a dimethylene-linked dithioether ligand and follows from our earlier work which has shown that the o-C 6 H 4 (CH 2 EMe) 2 (E = S, Se, Te) are remarkably effective ligands for a range of late transition metal ions. [26] The occurrence of a metallocyclic structure with bridging bidentate o-C 6 H 4 (CH 2 SMe) 2 ligands in the case of the Mo VI species, may be a consequence of the sterically demanding oxylyl linkage and the small radius of Mo VI . We have shown previously that the E-M-E chelate angle in transition metal complexes involving the o-C 6 H 4 (CH 2 EMe) 2 (E = S, Se or Te) ligands is invariably close to 100°.…”

“…We have shown previously that the E-M-E chelate angle in transition metal complexes involving the o-C 6 H 4 (CH 2 EMe) 2 (E = S, Se or Te) ligands is invariably close to 100°. [26] In the dinuclear 2 SEt}] (δ = 225 ppm). [20] The poor solubilities of the yellow [MoO 2 Cl 2 ([n]aneS 4 )] (n = 12 or 14) in solvents which would not react with the complex hindered attempts to obtain solution spectroscopic data for these species.…”

Versatile coordination chemistry of rhodium complexes containing the bis(trimethylsilylmethyl)tellane ligand

“…One possibility for the species giving rise to the observed 125 Te chemical shift is trans-[RhCl 2 {Te(CH 2 SiMe 3 ) 2 } 4 ] + with a Cl À counter ion (see Table 4). Analogous chalcogenoether complexes are known, as exemplified by [RhCl 2 {o-C 6 H 4 (CH 2 EMe 2 ) 2 } 2 ]Y (E = S or Se, Y = PF À 6 ; E = Te, Y = Cl À ) [27].…”