Homoleptic Copper(I) and Silver(I) Complexes with o-Phenylene-Backboned Bis(thioethers), Bis(selenoethers), and Bis(telluroethers):  Synthesis, Multinuclear NMR Studies, and Crystal Structures of [Cu{o-C₆H₄(SeMe)₂}₂]PF₆, [Cu{o-C₆H₄(TeMe)₂}₂]PF₆, and [Ag_n{μ-o-C₆H₄(SeMe)₂}_n{o-C₆H₄

Abstract

Homoleptic copper(I) and silver(I) complexes [M(L-L) 2 ]X (M ) Cu, X ) PF 6 ; M ) Ag, X ) BF 4 ; L-L ) o-C 6 H 4 (EMe) 2 ; E ) S, Se, Te) have been prepared and characterized by analysis, FAB mass spectrometry, and multinuclear NMR spectroscopy ( 1 H, 77 Se, 125 Te, 63 Cu, 109 Ag). Variable-temperature NMR studies have been used to probe various exchange processes occurring in solution. Single-crystal X-ray structural studies show that the Cu( [trigonal, a ) 13.632(6) Å, c ) 67.983(4) Å, R3 hc, Z ) 18] are isostructural and exist as mononuclear species with chelating bis(seleno-and bis(telluroethers), respectively, whereas the single-crystal structure ofanions and CH 2 Cl 2 solvent molecules. The o-C 6 H 4 (SeMe) 2 ligands in the latter exist as a mixture of invertomers within the infinite chains; the chelating ones adopt the meso arrangement while the bridging ones occur as the DL form. This is the first structurally characterized complex involving a bridging o-phenylene group 16 donor ligand and the first case of both invertomers occurring in a single complex.

Probing the Antioxidant Action of Selenium and Sulfur Using Cu(I)-Chalcogenone Tris(pyrazolyl)methane and -borate Complexes

“…The Cu−Se bond lengths for 1 (2.30 Å), 3 (2.29 Å and 2.31 Å), and 6 (2.31 Å) are comparable, whereas the Cu−Se bond in 8 (2.33 Å) is slightly longer. The Cu−Se bond distances in 1 , 3 , 6 , and 8 are comparable to the Cu−Se bond distance of 2.30 Å in the Cu III -bis-diselenolene complex reported by Ribas et al, but shorter than most reported copper−selenium complexes such as the selone [Cu(1,10-phen) 2 (C 5 H 10 N 2 Se)][2ClO 4 ] (2.49 Å); the selenolate [CuSe(2,4,6- i Pr 3 C 6 H 2 )] 2 [bipy] 2 (2.45 Å); the selenoether [Cu( o -C 6 H 4 (SeMe) 2 ) 2 ]-[PF 6 ] (2.42 Å);and the selenium macrocycle [Cu(C 11 H 14 Se 2 ) 2 ][BF 4 ] (avg. 2.41 Å) .…”

Selenomethionine-Substituted Thermus thermophilus Cytochrome ba3: Characterization of the CuA Site by Se and Cu K-EXAFS

“…The coordination chemistry of copper selenolates and selenoethers is predominately polynuclear, with both terminal and bridging Se atoms present in the structures. For selenides and selenolates, Cu−Se distances range from 2.30 to 2.44 Å ( − ), while for selenoethers there is a tendency toward longer distances (2.42−2.52 Å) ( − ). Se(Met) derivatives of cupredoxins have been reported to have resonance Raman spectra identical to those of the naturally occurring S(Met) proteins (), but no EXAFS data on the Cu−Se bond lengths were reported.…”

The Selenocysteine-Substituted Blue Copper Center: Spectroscopic Investigations of Cys112SeCys Pseudomonas aeruginosa Azurin

“…As stated above, few if any Cu(II) selenolate complexes have been described in the literature. The coordination chemistry of selenolates and selenides is predominately polynuclear, with both terminal and bridging Se atoms present in the structures. − Cu(II) selenoether complexes are known, but tend toward demetalation and formation of diselenide bonds. − From this limited literature, trends in Cu(I)−Se distances can be discerned, with Cu(I)−selenide and −selenolate bond lengths ranging from 2.3−2.45 Å and Cu(I)−selenoether bond lengths in the range 2.40−2.55 Å. Thus, both the Cu(II)−Se (2.30 Å) and the Cu(I)−Se (2.32 Å) are within the range for Cu(I) selenolates, but very close to the lower end.…”