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2.
Photophysical Behaviour of Syringaldehyde on pH and α-Cyclodextrin :
Comparison with β-Cyclodextrin
J.
Prema Kumaria*, G. Allen Gnana Raja
a
Department of Chemistry and Research Centre, Scott Christian College,
(Autonomous), Nagercoil, Kanyakumari, Tamil Nadu, 629003, India.
a*Assistant Professor aAssociate Professor, E-mail:
premarussel@rediffmail.com,
Mobile No. 0091-94892 83471
Abstract:
The photophysical properties of syringaldehyde [4-hydroxy-3,5-dimethoxy
benzaldehyde HDMB] on pH and α-cyclodextrin [α-CD]
have been investigated. This behavior indicates the formation of
an intramolecular charge transfer [ICT] state through relaxation
from the normal excited state. HDMB include more deeply in the
cyclodextrin cavity of β-CD than α-CD, because the cavity size
is smaller for α-CD than for β-CD. Cyclodextrin studies confirm
that hydroxyl group is present in the interior part of the
cavity and the aldehyde group is present in the upper part of
both α & β-CD cavity. HDMB forms a 1:1 inclusion complex with α
& β-CD. A mechanism is proposed to explain the inclusion process.
KEYWORDS: pH effect, α & β-cyclodextrin, Syringaldehyde
[4-hydroxy-3,5-dimethoxybenzaldehyde], intramolecular charge
transfer.
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