Umsetzungen von Halbsandwich‐Rhenium(V)‐Oligochalkogenidkomplexen mit Acetylen‐dicarbonsäuredimethylester. Molekülstrukturen der neuen 1,2‐Dicarbomethoxy‐ethen‐1,2‐dichalkogenat‐Chelatverbindungen Cp*Re[S₂C₂(COOMe)₂]₂ und Cp*Re(N^tBu)[Se₂C₂(COOMe)₂]

Abstract

Inhaltsübersicht.(1) Bei der Umsetzung von Cp*Re(S3)(S4) (1a) mit Acetylen‐dicarbonsäuredimethylester (dmad) entsteht über die blaue Zwischenstufe Cp*Re(S4)[S2C2(COOMe)2] (2a) hinweg der rote Bis(ethen‐1,2‐dithiolato)‐Komplex Cp*Re[S2C2(COOMe)2]2 (3a). Auch die Tetrasulfidorhenium‐Komplexe Cp*Re(L)(S4) (L = O (4a), NtBu (5a)) ergeben mit dmad das Produkt 3a, während die analogen Tetraselenidorhenium‐Verbindungen Cp*Re(L)(Se4) (4b und 5b) nur zu Cp*Re(L)[Se2C2(COOMe)2] (L = O (6b), NtBu (7b)) umgesetzt werden. Nach den Röntgenstrukturanalysen sind die Ethen‐1,2‐dithiolato‐rhenium‐Chelatringe in 3a entlang des S …︁ S Vektors zum Cp*‐Liganden hin abgeknickt (Winkel zwischen den Ebenen ReS2/S2C2 159,2°), während der ReSe2C2 Chelatring in 7b eben ist.

Reactions of Dithiolate Ligands in Mononuclear Complexes of Rhenium(V). 2. Cp‘ ‘ReCl2(η2-SC3H6S) and Related Derivatives

“…The dinuclear product, mentioned above, appears to be formed under the conditions of the mass spectroscopy experiment. The Re−S bond length of 2.2525(18) Å is quite short compared to those of other Re(V) thiolates (often 2.30−2.40 Å) and is consistent with assignment of π-donating character to the thiolate sulfur. The relatively strong donor properties of the thiolate ligand are also reflected in the unsymmetrical coordination of the Cp‘ ‘ ligand.…”

“…Thiols were dried over anhydrous MgSO 4 and filtered before use, and triethylamine was distilled before use. Cp‘ ‘ReCl 4 , 1 , was prepared from Cp‘ ‘ReO 3 according to the literature report 15a. IR spectra were recorded as KBr pellets with a Nicolet Impact 410 spectrometer.…”

Rhenium(V) Complexes with Selenolato‐ and Tellurolato‐Substituted Schiff Bases – Released PPh3as a Facile Reductant

“…The Re–Se bonds between 2.439(1) and 2.5003(6) Å are relatively short and similar bond lengths have hitherto only been found in some rare examples of Re(V) complexes with terminal phenylselenolato complexes,, , while in the majority of their rhenium complexes such ligands bridge two low‐valent rhenium atoms and the related Re–Se bond are in the range of 2.6 Å or longer . Short Re–Se bonds are also established in binuclear rhenium compounds with Re–Re bonds or diselenolene complexes , . Most of the few rhenium complexes with tellurolato ligands are carbonyl compounds of Re(I) and they have Re–Te bond lengths between 2.760 and 2.811 Å , , , .…”

“…They mainly contain simple, unsubstituted phenylselenolato ligands . A few more rhenium(V) complexes with special ligands such as acylselenoureas, a diselenolenate, and pyridine‐2‐selenolate have been reported . The rarity of these reports may result from the more complicated syntheses of heavier organochalcogenolato ligands.…”

Oxidorhenium(V) and Rhenium(III) Complexes with Arylselenolato and ‐tellurolato Ligands

“…[21][22][23][24][25][26][27][28][29][30][31][32][33] Reports about well-defined rhenium(III) or rhenium(V) complexes containing arylselenolato or -tellurolato ligands are even more rare. In addition to some oxidorhenium compounds, [34][35][36][37] recently a series of phenylimido chelates of rhenium(V) has been reported with the corresponding diselenides and ditellurides as starting materials. Selective reduction of the dichalcogenides was performed by phosphines, which were released during the reaction of [Re-(NPhR)Cl 3 (PPh 3 ) 2 ] complexes (R=H, F, CF 3 ) with the corresponding dichalcogenides.…”