Low temperature stopped-flow studies in inorganic chemistryBased on the presentation given at Dalton Discussion No. 4, 10–13th January 2002, Kloster Banz, Germany.

Abstract

Low temperature stopped-flow methods together with diode array instrumentation have become extremely useful for studying reactions that are too fast at ambient temperatures and/or for detecting reactive intermediates that can only be observed at low temperatures. Furthermore, global analysis fitting methods are described that allow the analysis of complex reaction mechanisms. To illustrate the method the reaction of dioxygen with the tripodal copper() complex [Cu(Me 2 -uns-penp)(CH 3 CN)]ClO 4 (Me 2 -uns-penp = (2-dimethylaminoethyl)bis(2-pyridylmethyl)amine) is discussed as an example.

Aromatic Hydroxylation in a Copper Bis(imine) Complex Mediated by a μ‐η2:η2 Peroxo Dicopper Core: A Mechanistic Scenario

“…Time-resolved spectra could be obtained by low-temperature stopped-flow techniques; a typical example of the oxidation reaction in methanol is shown in Figure 9. The spectra resemble those obtained previously by some of us in kinetic studies on the related imine systems [Cu 2 - [27] Again, similar to these systems, we could not detect the buildup of a dioxygen adduct. This is in contrast to the complex [Cu 2 …”

“…Details of such studies have been described previously. [27] Single-crystal structure analysis: The X-ray crystallographic data for complex I were collected at 173 K on a STOE IPDS diffractometer equipped Scheme 1. Hydroxylation of the Cu 2 A C H T U N G T R E N N U N G (DAPA) core of I leading to product II (charges are omitted).…”

Crystallographic Characterization of a Synthetic 1:1 End‐On Copper Dioxygen Adduct Complex

“…[1][2][3][14][15][16] In related studies we showed, however, that the high reactivity of the transient species can be moderated by use of sterically more demanding ligands with stronger N-donor character, such as Me 6 tren. [15] This success led us to employ the sterically congested superbasic [17] tren derivative tris(tetramethylguanidino)tren (TMG 3 tren) [18] as a ligand and in a recent study we were eventually able to obtain a stable 1:1 Cu/O 2 adduct at low temperatures (Scheme 2).…”

Syntheses and characterization of copper complexes with the ligand 2-aminoethyl(2-pyridylmethyl)-1,2-ethanediamine (apme)

“…In our own work, based on these important results, we started to follow this kind of chemistry using derivatives of the compound tris(2-aminoethyl)amine (tren, Scheme 1, R =H) [9,[21][22][23][24] that can be regarded as the parental amine of tripodal ligands such as tmpa [25].…”