International Summer School PROGRAM - Laboratoire d'Infochimie ...

Crown-containing derivatives of naphthopyrans: cation
binding, photochemical and fluorescent properties
A.B. Smolentsev 1 , E.M. Glebov 1 , V.V. Korolev 1 , S.V. Paramonov 2 , O.A. Fedorova 2
1 – Institute of Chemichal Kinetics and Kombustion SB RAS, Novosibirsk , Russia
2 - Nesmeyanov Institute of Organoelement Compounds RAS, Moscow, Russia
S_art@ngs.ru
Photochromic molecules containing macrocyclic moiety have attracted much
interest in molecular chemistry as components of functional materials. Examples of
potential applications of these compounds include: photoswitching transport through
membranes, optical information storage, photoswitching extraction of metal cations.
A
O
O
O
O
O
O
B
O
O N
O O
O
Scheme 1
O
O
O
O O
Crown-containing naphtopyrans (chromenes) A, B, C (scheme 1) and their
crownless analogues were used in the work. All studied compounds, upon UV
irradiation, yield open colored forms. Then in the course of dark reaction open form of
chromenes turns into colorless closed form. Moreover, naphtopyrans A and B, upon UV
irradiation, undergo irreversible geometrical isomerisation.
All studied crown-containing compounds form host-guest complexes with Mg 2+ ,
and Ba 2+
cations. The presence of metal cations in the solution leads to partial
destabilization of the photoinduced form of С and consequently decreases its lifetime.
Nevertheless, complexation doesn’t effect on the spectroscopic and kinetic properties of
the colored forms of A and B.
Naphthopyran B fluoresces with maxima at 530 nm. It’s remarkable that only
trans- isomer of B is fluorescent, while cis- isomer is not. For this reason trans-cis
isomerisation of B leads to disappearance of fluoresce. The presence of metal cations in
the solution also leads to significant decrease of fluorescence quantum yield of B.
This work was supported by the Russian Foundation of Basic Research (grants
№11-03-00268 and №09-03-00283).
C
O