Creutz–Taube complex

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The Creutz-Taube complex is a metal complex with the formula [ Ru ( NH3) 5 ] 2 ( C4H4N2 ) 5 .

The cationic Creutz-Taube complex is a mixed-valence compound, including metal ions in two different oxidation states. The complex has been studied in detail in order to investigate the effects of electron transfer by the inner-sphere mechanism between metal centers.

The complex is named after Carol Creutz, who synthesized the complex first and their supervisor, Henry Taube, who was recognized for its work to the intramolecular electron transfer with the Nobel Prize.

Properties

The complex consists of two Rutheniumkernen, which are surrounded by five ammonium ligands. The cores are connected via the nitrogen atoms of a central bridging pyrazine ligands. The special feature of the complex is that the ruthenium atoms have a formal charge of 2.5 . Was crystallographically shows that the two metal centers are electronically equivalent.

One characteristic of mixed complexes is a strong absorption in the near infrared. The Creutz-Taube complex has an absorption maximum at 1570 nm. This absorption is described as inter -valence charge -transfer band.

Synthesis

The ion was first as a hydrated salt [Ru (NH3 ) 5] 2 ( C4H4N2 ) ( O3SC6H4CH3 ) 5.3H2O won.

It is made in two steps from the Pyrazinkomplex [Ru (NH3 ) 5 ( C4H4N2 )] 2 :

The Creutz-Taube complex illustrates the advantages of ruthenium complexes for the study of redox reactions. Ru (II) -, and Ru (III ) ions can be converted under mild conditions into each other. Complexes with metal ions of various oxidation states, are kinetically inert.