• Journal of Photoscience
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• v.10 no.1
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• pp.165-173
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• 2003

m-Phenylene-linked biscarbenes, bisnitrenes and carbenonitrenes can be formed photochemically from appropriate nitrogenous precursors. Generation of such reactive intermediates under matrix-isolation conditions allows for their characterization by spectroscopic techniques such as ESR, UV /vis and IR. The latter method is also useful in characterizing secondary products derived from these reactive intermediates. Computational chemistry methods complement experimental IR data, aiding, thus, in identification of such compounds. In addition electronic structure calculations help in developing qualitative and semi-quantitative models, which can be useful in predicting ground-state multiplicities. The parent systems of m-phenylene-linked carbenes and nitrenes have high-spin ground states, but a switching to lower multiplicity can be achieved by chemical substitution. The ground state and various low-lying excited states of m-phenylenecarbenonitrenes can be reasonably approximated by simple valence-bond depictions. Finally, m-phenylenecarbenonitrenes are photoreactive in the inert matrix isomerizing to cyclopropene derivatives.

• Bulletin of the Korean Chemical Society
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• v.24 no.11
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• pp.1702-1704
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• 2003

• Proceedings of the KOSOMBE Conference
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• v.1997 no.05
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• pp.11-15
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• 1997

We used the photoreactive poly(allylamie) (PPA) as the hydrophilic membrane to control the release of drug from polyurethane(PU). PPA was covalently bonded onto PU surface through the highly reactive nitrene intermediate upon UV light irradiation $(3.3mW/cm^2)$ at 254nm for 5min. Thus the release rate of rifampicin from PU surface was controlled. To know the characteristics of PU surface bonded with PPA, we measured the ATR-FTIR, ESCA, Static Contact Angle and SEM. From these, we suggest that PPA as a hydrophilic membrane is enable to control the release rate of a hydrophobic drug from polymer without the change of bulk property.

• Proceedings of the KOSOMBE Conference
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• v.1997 no.05
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• pp.47-50
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• 1997

We synthesized N-Hydroxysuccinimidyl (NHS) azidobenzoate as a cross-linking reagent for immobilization of peptide onto the solid surface. Thin polystyrene(PS) films spin-coated with a NHS azidobenzoate solution were exposed with ultraviolet light at 245nm$(3.3mW/cm^2)$ for 5 min. The NHS active ester groups became covalently attached to the polymer via photogenerated, highly reactive nitrene intermediates derived from NHS azidobenzoate. Using this technique, it is demonstrated that well-defined surface regions can be functionalized with a minimum observable feature size of 1mm for UV exposure. Through reaction of this functionalized PS surface with primary amine-containing biomolecules, biological molecule had been immobilized on the polymer surface.