US EPA

1468551 

Journal Article 

Wavelength-dependent stereodifferentiation in the fluorescence quenching of asymmetric naphthalene-based dyads by amines 

Abad, S; Pischel, U; Miranda, MA 

2005 

1 

DUPE - Journal of Physical Chemistry A
ISSN: 1089-5639
EISSN: 1520-5215 

109 

12 

2711-2717 

English 

16833581 

10.1021/jp047996a 

WOS:000227993600001 

https://www.scopus.com/inward/record.uri?eid=2-s2.0-17144374027&doi=10.1021%2fjp047996a&partnerID=40&md5=d8061d9126f9a73553ae357444d62f87
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In the present contribution, wavelength has been used as a tunable parameter to achieve selective control of the photophysics of two novel asymmetric bichromophoric dyads composed of naphthalene units, i.e., 6-methoxynaphthalene (NPX) and 1-methylnaphthalene (NAP) derivatives, with different electronic properties, connected by an amide spacer [(S,S) and (S,R)-NPX-NAP]. As model systems, relevant monochromophoric compounds (NPX-M and NAP-M) have also been investigated. While upon excitation at 325 nm the light energy remained in the NPX moiety, at 290 nm an efficient singlet-singlet energy transfer (phi(SSET) of about 97%) from the NAP unit to the NPX chromophore dominated. A remarkable stereodifferentiation was observed in the excited-state quenching by triethylamine via exciplex formation. The results demonstrate that it is possible to control configuration-dependent interactions in the excited state by wavelength tuning. This can be rationalized through intramolecular interactions of pi systems leading to modulation of the redox properties.