Microenvironments of 3-[2-imidazolylazo]benzoyl-poly(ethylenimine): High affinity for Ni(II) and 9-anthracenecarboxylate ions

Suh, Junghun; Kim, Mahn-Jong

doi:10.1016/0045-2068(92)90046-6

Cited by 5 publications

(1 citation statement)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Long alkyl chains such as Lau group attached to PEI form clusters to minimize exposure to water . It is also reported that bulky aromatic residues such as azobenzene derivatives form clusters when they are attached to PEI . Thus, clusters containing both TP and Lau groups would be formed on the backbone of PEI containing both TP and Lau groups.…”

Section: Discussionmentioning

confidence: 99%

Catalytic Activity of Ni(II)−Terpyridine Complex in Phosphodiester Transesterification Remarkably Enhanced by Self-Assembly of Terpyridines on Poly(ethylenimine)

Suh

Hong

1998

J. Am. Chem. Soc.

Self Cite

View full text Add to dashboard Cite

To enhance the catalytic activity of metal-terpyridyl complexes toward transesterification of an RNA model [(2-hydroxypropyl)-p-nitrophenyl phosphate, HPNPP], the conformation of terpyridyl moieties assembled on poly(ethylenimine) (PEI) is optimized by attaching the Ni(II) complex of a terpyridyl derivative (Ni II TP) and lauryl (Lau) group to PEI in random combinations. The catalytic activity per Ni(II) center for transesterification of HPNPP varies by up to several thousand times depending on pH as the content of Ni II TP or Lau is changed. The best catalyst obtained is [Ni II TP] 5 Lau 12 PEI, in which the contents of Ni II TP and Lau are 5 and 12 residue mol %, respectively. The catalytic activity of [Ni II TP] 5 Lau 12 PEI expressed in terms of k cat is much higher than those of previously reported binuclear metal complexes whose structures were designed through deliberate planning. In the PEI derivatives containing Ni II TP and Lau, several Ni II TP groups can be positioned in proximity in the hydrophobic clusters formed on the polymer. When the Ni II TP groups take productive positions, the two phosphoryl-oxygen bonds and the hydroxyl group of HPNPP can be effectively activated. Thus, artificial active sites comprising multiple catalytic groups are obtained by self-assembly of the catalytic groups. Moreover, cooperative action among the catalytic groups is optimized through combinatorial approach.

show abstract

Section: Discussionmentioning

confidence: 99%