In:
European Journal of Inorganic Chemistry, Wiley, Vol. 2015, No. 29 ( 2015-10), p. 4839-4847
Abstract:
Generation‐dependent cooperation was observed in the reduction of molecular oxygen by a series of Cu 2+ complexes of pyridine‐modified polyamidoamine (PAMAM) dendrimers. The cooperative behavior of the metal ions was examined by preparing (G2–G6)‐ dendri ‐PAMAM‐(Py) n and testing the dendrimers for their ability to reduce oxygen catalytically in the presence of several Cu 2+ ion concentrations. Spectrophotometric measurements during the reactive metallic ion titrations revealed that the maximum numbers of reactive Cu 2+ ions available for O 2 reduction were 4.8, 7.6, 22.2, 57.3, and 81.7 in each of the second‐ to sixth‐generation (G2–G6) dendrimer complexes, respectively. An analysis revealed that each Cu 2+ ion worked independently as an active center in the G2 to G4 dendrimer complexes. By contrast, pairs of Cu 2+ ion active species were present in the G5 and G6 dendrimer complexes. A kojic acid titration indicated that the copper ions were proximal and formed a bicopper active center in the G5 and G6 dendrimer complexes. Catalytic reactions with catechol as a reducing agent further demonstrated the activity of the dinuclear copper center in the G5 and G6 dendrimer complexes. The present findings suggest that generations of dendrimer–metal complexes can alter their catalytic behavior.
Type of Medium:
Online Resource
ISSN:
1434-1948
,
1099-0682
DOI:
10.1002/ejic.v2015.29
DOI:
10.1002/ejic.201500540
Language:
English
Publisher:
Wiley
Publication Date:
2015
detail.hit.zdb_id:
1475009-0