Dithione, the antipodal redox partner of ene-1,2-dithiol ligands and their metal complexes

Characterization and Structural Insights of the Reaction Products by Direct Leaching of the Noble Metals Au, Pd and Cu with N,N′-Dimethyl-piperazine-2,3-dithione/I2 Mixtures

“…In the copper(I) complex 3′ , the tetrahedral geometry allows for a bonding interaction between the sulfur p and metal d orbitals. These results are in agreement with those previously reported by P. Basu et al [ 27 , 28 ], on a study of Cu(I) (see Figure S11 ) and Cu(II) complexes with the same or similar ligands (Me 2 pipdt and i Pr 2 pipdt). In addition to crystals of [Cu( i Pr 2 pipdt) 2 ][PF 6 ] and [Cu(Me 2 pipdt) 2 ][PF 6 ], these authors succeed in isolating crystals of a Cu(II) derivative: [Cu( i Pr 2 pipdt) 2 ][BF 4 ] 2 .…”

“…The solution turned from light- to dark-green to purple, and the reaction went off in around 1 h. Following slow evaporation of THF and EtOH addition, crystals characterized as [Cu(Me 2 pipdt) 2 ]BF 4 ( 4 ) were obtained. It can be assumed that a copper(II) cationic complex is formed in solution (the green intermediate observed in this reaction) and that it undergoes spontaneous reduction to the more stable copper(I) complex, as earlier observed for similar compounds [ 27 , 28 ]. Copper(I) complexes with thione donors are not uncommon and those coordinated to biologically relevant ligands such as N , N ′-dimethylimidazole-thione or others, are of interest to elucidate how coordination to sulfur and selenium inhibits copper-mediated oxidative damage.…”

“…In the electronic spectra of [Cu(Me 2 pipdt) 2 ]I 3 ( 3 ), in addition to the triiodide related peaks, a peak appears at 530 nm. This peak can be assigned to a metal-to-ligand charge-transfer transition, according to recent studies on this class of complexes [ 28 ].…”

“…[Au III I 2 Me 2 pipdt]I 3 ( 1 ), [Pd II (Me 2 pipdt) 2 ]I 6 ( 2 ) and [Cu I (Me 2 pipdt) 2 ]I 3 ( 3 ) coordination compounds were isolated in satisfactory yields as the main leaching products. The coordination behavior of the ligand is invariably S,S bidentate, but 1 and 2 comprise square–planar d 8 metal Au(III) and Pd(II) complexes, while 3 involves a tetrahedrally coordinated d 10 -Cu(I) [ 27 , 28 ]. Additional results have shown that the 1+ oxidation state and the tetrahedral geometry are the preferred ones for copper complexes with these ligands.…”

Syntheses, spectroscopic, redox, and structural properties of homoleptic Iron(III/II) dithione complexes

“…The C-S and C-C bond lengths of the dithiolene moiety can change depending on the number of p electrons present 59 and thus be used to determine the oxidation state of Dt 0 in metallodithiolene complexes. The average C-S bond lengths of [ 60 Fe III (3,6-DBSQ) 3 (3,6-DBSQ ¼ 3,6-di-tert-butyl-1,2benzoquinone), 61 and Fe III (3,5-DBSQ) 3 (3,5-DBSQ ¼ 3,6-di-tertbutyl-1,2-benzoquinone).…”