Linked Life Data

19480433

Source:http://linkedlifedata.com/resource/pubmed/id/19480433

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
14
pubmed:dateCreated
2010-5-28
pubmed:abstractText
Three ruthenium nitrosyl-dye conjugates, namely, [((OMe)(2)bQb)Ru(NO)(Resf)] (RuNO-Resf), [((OMe)(2)bQb)Ru(NO)(Thnl)] (RuNO-Thnl), and [((OMe)(2)bQb)Ru(NO)(Seln)] (RuNO-Seln) have been synthesized using the tetradentate N4 dicarboxamido ligand H(2)(OMe)(2)bQb. Each nitrosyl of this series is conjugated to a phenoxazine-type heterotricyclic chromophore which has been systematically varied in a central position to test the effects of "heavy-atom" substitution (O = Resorufin; S = Thionol; Se = Selenophore) in photosensitization. The structure of the chloride-bound precursor {Ru-NO}(6) nitrosyl [((OMe)(2)bQb)Ru(NO)(Cl)] (RuNO-Cl) and three nitrosyl-dye conjugates, namely, RuNO-Resf, RuNO-Thnl and RuNO-Seln, have been determined by X-ray crystallography. All three nitrosyl-dye conjugates exhibit sharp (1)H NMR spectra (S = 0 ground state) and nu(NO) stretches in the IR spectrum in the region 1825-1855 cm(-1), typical of {Ru-NO}(6) nitrosyls. The presence of a heavy atom in the bound dye gives rise to a systematic red-shift in the electronic absorption spectrum, shifting from RuNO-Resf (lambda(max) = 500 nm) to RuNO-Thnl (lambda(max) = 530 nm) to RuNO-Seln (lambda(max) = 535 nm). Results of careful measurements with monochromatic light sources indicate that heavy-atom substitution in the coordinated dye makes the resulting nitrosyl-dye conjugates more susceptible to light of longer wavelength (lower energy). Density functional theory (DFT) calculations on RuNO-Cl, RuNO-Resf, RuNO-Thnl, and RuNO-Seln have been performed to gain insight into the electronic structure of the {dye-Ru-NO} frame and the nature of transition(s) that sensitizes these conjugates to lights of longer wavelengths and promote NO photolability. Results of this study provide an explanation for the sensitization observed in our strategy of direct attachment of dye molecules to {Ru-NO}(6) nitrosyls. This strategy could lead to eventual isolation of designed metal nitrosyls that are sensitive to red- or near-infrared light and hence potential photodynamic therapy (PDT) agents for treatment of malignancies with high doses of NO.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
1520-510X
pubmed:author
pubmed:issnType
Electronic
pubmed:day
20
pubmed:volume
48
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
6904-17
pubmed:meshHeading
pubmed:year
2009
pubmed:articleTitle
Photosensitization of ruthenium nitrosyls to red light with an isoelectronic series of heavy-atom chromophores: experimental and density functional theory studies on the effects of O-, S- and Se-substituted coordinated dyes.
pubmed:affiliation
Department of Chemistry and Biochemistry, University of California Santa Cruz, Santa Cruz, California 95064, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't