Gold Complexes with the Selenolate Ligand [2-(Me₂NCH₂)C₆H₄Se]⁻

Abstract

The reaction of [2-(Me(2)NCH(2))C(6)H(4)Se]M (M = Li, K) with the gold(phosphine) complexes [AuCl(PR(3))] gives the mononuclear gold-selenolate species [Au{SeC(6)H(4)(CH(2)NMe(2))-2}(PPh(3))] (1) or [Au{SeC(6)H(4)(CH(2)NMe(2))-2}(PPh(2)py)] (2), respectively. The treatment of the [2-(Me(2)NCH(2))C(6)H(4)Se]M with [Au(2)Cl(2)(mu-P-P)] [P-P = bis(diphenylphosphino)methane (dppm), bis(diphenylphosphino)ethane (dppe), 1,1'-bis(diphenylphosphino)ferrocene (dppf)] derivatives gives complexes with stoichiometry [Au(2){SeC(6)H(4)(CH(2)NMe(2))-2}(2)(mu-P-P)] [P-P = dppm (3), dppe (4), or dppf (5)]. These complexes exhibit a different structural framework, that is, 4 crystallizes as a chain polymer with intermolecular aurophilic bonding, while 5 shows an intramolecular Au(I)...Au(I) interaction. The gold(III) derivative Bu(4)N[Au(C(6)F(5))(3){SeC(6)H(4)(CH(2)NMe(2))-2}] (6) is obtained by reaction of [2-(Me(2)NCH(2))C(6)H(4)Se]K and Bu(4)N[AuBr(C(6)F(5))(3)], in a 1:1 molar ratio. These species exhibit luminescence which probably arises from a mixed (3)LMMCT and (3)MC excited state. The emission properties in these complexes seem to be useful for structural predictions and lead to the proposal of intermolecular aggregation in the solid state and frozen solution for complexes 1, 2, 3, whose crystal structures have not been elucidated.

Synthesis, characterization and catalytic activity of gold complexes with pyridine-based selone ligands

“…(Au-Se av = 2.441 Å) are comparable to the distances observed in the gold complexes containing selone ligands[66][67][68]. The Au-Se distances (2.4391(6) and 2.4427(6) Å) in complex 2, which are longer than those of in Au(I) complex [AuCl(SeUr)] (Ur = NHC-derived selenoureas ligands) (2.353-2.398 Å)[67] and [Au 2 {SeC 6 H 4 (CH 2 -NMe 2 )-2} 2 (l-dppf)] (2.4245(5) and 2.4250(8) Å)[68].As shown in theFig. 2, there are two forms of gold in 2 unit cell.…”

Gold(I)-selenolate complexes: Synthesis, characterization and ligand exchange reactions

“…7 Recently, we have shown that trialkyl/aryl gold(I) chlorides (R 3 PAuCl, R = Me, Et or Ph) inhibit the GPx activity of the selenol 5 by forming gold(I)-selenolate complexes (6-8). 8 Gimeno and co-workers reported similar gold-selenolates (9)(10) bearing the N,N-dimethylbenzylamine moiety (figure 2). 9 It has been reported that the amino group in 5 plays an important role in the GPx activity as the Se• • • N non-covalent interactions in the key catalytic intermediates modulate the catalytic activity.…”

“…8 Gimeno and co-workers reported similar gold-selenolates (9)(10) bearing the N,N-dimethylbenzylamine moiety (figure 2). 9 It has been reported that the amino group in 5 plays an important role in the GPx activity as the Se• • • N non-covalent interactions in the key catalytic intermediates modulate the catalytic activity. 8,10 In the natural GPx enzyme, two amino acid residues, glutamine (Gln) and tryptophan (Trp), form a 'catalytic triad' with the Sec residue at the active site.…”

An experimental and theoretical investigation on hypervalent organoselenium(II) halides: Case study of [2-(Et2NCH2)C6H4]SeX (X = Cl, Br, I)

“…Recently, we have reported on the synthesis, solution behaviour and molecular structures of various hypervalent organoselenium(II) compounds containing the 2-(Me 2 NCH 2 )C 6 H 4 [5,28] and 2-{Z(CH 2 CH 2 ) 2 NCH 2 }C 6 H 4 (Z ¼ O, NMe) [22] groups as well as metal organoselenolates containing the fragment [2e(R 2 NCH 2 ) C 6 H 4 ]SeeM (R ¼ Me, Et; M ¼ Au, Zn or Cd) [14,15]. As a development of these previous studies and with the aim to increase the basicity of the coordinating amine group we decided to use the 2-(N,N-diethylaminomethyl)phenyl group, 2-(Et 2 NCH 2 )C 6 H 4 , as a pendant arm ligand which can exhibit a (C,N) coordination towards the selenium centre.…”