Česká společnost chemická, pobočka Brno
Vás zve na přednášku, která se koná v místnosti 132, 1.NP, budova A11,
Kamenice 5, Přírodovědecká fakulty Masarykovy univerzity, Brno
ve čtvrtek 6. října 2011 ve 14:00 hod.
PROF. DANIEL FALVEY
UNIVERSITY OF MARYLAND, COLLEGE PARK, MD, USA
Mechanistic Design of High-Wavelength Photoreleasable Protecting
Groups and Applications to Photorheology.
Recent investigations have focused on the mechanistic design, synthesis and study of
photoreleasable protecting groups. The overall goal is to create a suite of protecting groups
whose release can be triggered using inexpensive visible light sources. One specific strategy
has been to photoinduced electron transfer from visible-light absorbing dyes to a protecting
group that can be activated through photoinduced single electron transfer. Specifically the
release of carboxylic acids phenacyl and 4-N-alkylpicolinium esters have been examined. An
example of one such reaction is shown below.
N
O
O
R
hν/Ru(bpy)3
ascrobic acid
H2-O
N HO
O
R
These reactions have recently been applied to the development of phototriggering reagents
that can rapidly and reversibly alter the viscosities of bulk liquids by catalyzing self-assembly
processes. For example, visible light triggered photorelease of cinnamate ions in the presence
of CTAB micelles has been shown to convert the latter from spherical structures into elongated
worm-like structures. This in turn causes the solution to convert from a free flowing fluid to a
gel-like state. Ultraviolet light can reverse this process through trans-cis photoisomerization of
the released cinnamate ions.
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doc. Ing. Vladimír Šindelář, Ph.D.
jednatel pobočky
prof. RNDr. Jiří Pinkas, Ph.D.
předseda pobočky