Linked Life Data

19382765

Source:http://linkedlifedata.com/resource/pubmed/id/19382765

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
10
pubmed:dateCreated
2009-5-8
pubmed:abstractText
Two bis(m-phenylene)-32-crown-10 derivatives containing two pyridyl or carboxyl groups were made. They were used to prepare three bis(m-phenylene)-32-crown-10-based discrete rhomboids by coordination-driven self-assembly with high yields. The formation of these crown ether-based rhomboids was confirmed by NMR, UV-vis, CSI-TOF-MS, and elemental analysis. The complexation of these crown ether-based assemblies with paraquat (N,N'-dimethyl-4,4'-bipyridinium) was studied. The complexation of neutral bis(crown ether) rhomboid 1 with paraquat was found to be statistical with a 1:2 stoichiometry. The average apparent association constant K(av) of the complexation of rhomboid 1 with paraquat was found to be about 8.8(+/-0.8) x 10(3) M(-1) in acetone, about 17 times higher than the reported association constant value for the complexation of the corresponding simple bis(m-phenylene)-32-crown-10 with paraquat. This is possibly because the carboxylate groups provide additional noncovalent interactions between the host and guest. No obvious complexation was observed between the cationic rhomboids and paraquat when studied by NMR, UV-vis, and CSI-TOF-MS analysis. This could be attributed to the combination of the charge repulsion between cationic pyridinium rings and cationic platinum atoms and the weak pi-pi stacking and charge transfer interactions between the phenyl rings and the pyridinium rings caused by the electron-withdrawing effect of the cationic platinum atoms.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
1520-6904
pubmed:author
pubmed:issnType
Electronic
pubmed:day
15
pubmed:volume
74
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
3905-12
pubmed:meshHeading
pubmed:year
2009
pubmed:articleTitle
Synthesis of bis(m-phenylene)-32-crown-10-based discrete rhomboids driven by metal-coordination and complexation with paraquat.
pubmed:affiliation
Department of Chemistry, Zhejiang University, Hangzhou 310027, China.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't