Darstellung und Kristallstruktur der Kupfer(I)‐chalkogenolat‐2,2′‐Bipyridin‐Komplexe [CuS(2,4,6‐iPr₃C₆H₂)]₄(Bipy)₂ und [CuSe(2,4,6‐iPr₃C₆H₂)]₂(Bipy)₂

Abstract

Die oligomeren homoleptischen Kupfer(I)‐chalkogenolat‐Verbindungen [CuS(2,4,6‐iPr3C6H2)]x=4,8 (1, 2) und [CuSe(2,4,6‐iPr3C6H2)]6 (3) wurden mit 2,2′‐Bipyridin (Bipy) zu dem tetranuklearen Kupferkomplex [CuS(2,4,6‐iPr3C6H2)]4(Bipy)2 (4) und dem dinuklearen Komplex [CuSe(2,4,6‐iPr3C6H2)]2(Bipy)2 (5) umgesetzt, deren Strukturen durch Einkristall‐Röntgenstrukturanalysen bestimmt wurden. In dem achtgliedrigen Cu4S4‐Ring von 4 mit Sesselkonformation sind die Kupferatome über μ2‐verbrückende Thiolat‐Liganden verknüpft, wobei nur 2 Kupferatome von 2,2′‐Bipyridin koordiniert werden. Der entsprechende Kupfer(I)‐selenolat‐Komplex (5) bildet einen gefalteten viergliedrigen Cu2Se2‐Ring mit μ2‐verbrückenden Selenolat‐Liganden. Der CuCu‐Abstand ist mit 2.52 Å relativ kurz. Im Gegensatz zu der Umsetzung mit 2,2′‐Bipyridin entsteht aus 1 bzw. 2 und Phenantrolin (Phen) ein dinuklearer Komplex [CuS(2,4,6‐iPr3C6H2)] 2(Phen)2 (10). Während 5 sich offensichtlich ohne Zerfall löst, wie NMR‐spektroskopische und kryoskopische Untersuchungen zeigen, dissoziiert 4 in Lösung in kleinere Aggregate, die miteinander im Gleichgewicht stehen. Das elektrochemische Verhalten von 4, 5 und 10 wurde in CH2Cl2 studiert. In allen Fällen wurden keine reversiblen Redoxprozesse beobachtet.

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) .…”

Metal‐Controlled Stereoselectivity in Complex Formation: Assembly of Tetranuclear Copper(I) Complexes with Four Stereogenic Nitrogen Donor Functions in all‐(R) and all‐(S) Configurations

“…Both frames differ in the magnitude of their Cu-SϪCu angles. For [Cu 4 {SC 6 H 2 (2,4,6-iPr) 3 } 4 (bipy) 2 ], [14] both acute and obtuse angles are present, whereas only acute angles are observed in [Cu 4 (StBu) 4 (PPh 3 ) 2 ]. [15] Of more general importance is the new finding that ligands derived from 3,7-dialkyl-3,7-diazanonane-1,9-dithiol-ate stabilise complexes of coordination number 4 with a nonplanar ligand field.…”

“…Comparable geometrical features have also been found by Becker et al and by Block et al in respectively. Coordination principles in tetranuclear thiolate complexes with planar copper frameworks that are different from those observed in 1 and 2 have been found in [Cu 4 {SC 6 H 2 (2,4,6-iPr) 3 } 4 (bipy) 2 ] [14] and [Cu 4 (StBu) 4 -(PPh 3 ) 2 ], [15] respectively. In both cases, two mononuclear [Cu(SR) 2 L] subunits with tetrahedral CuN 2 S 2 or trigonalplanar CuPS 2 coordination sites act as ligands towards ''naked'' Cu I ions, forming linear SϪCuϪS units within cyclic Cu 4 S 4 frames.…”

Synthesis and Structural Characterization of Copper(I) Phenylselenolate Complexes Stabilized by N, N′‐Donor Ligands

“…Grützmacher et al reported similar decomposition reactions for a number of copper chalcogenolato compounds, although they could also identify a relatively large complex subunit such as [{CuSe (2,4,6-iPr 3 C 6 H 2 )} 2 (bpy) 2 ] by NMR spectroscopy in solution. [12] …”

“…To the best of our knowledge, the first compound of this class, the dinuclear complex [Cu{Se (2,4,6-iPr 3 C 6 H 2 )} 2 (2,2Ј-bpy) 2 ], was obtained by the reaction of the hexanuclear cluster [Cu{Se (2,4,6-iPr 3 C 6 H 2 )}] 6 with 2,2Ј-bipyridine. [12] The resulting copper complex forms a folded four-membered Cu 2 Se 2 coordination N,NЈ-donor ligands prevents from the rapid formation of less soluble polymers and gives access to three new compounds, [{Cu 2 (bpy) 2 ring with μ 2 -coordinated phenylselenolato ligands. NMR spectroscopic and cryoscopic measurements of this complex indicate that the solid-state structure is maintained in solution.…”