%0 Online Multimedia
%A Gassensmith, Jeremiah J.
%A Arunkumar, Easwaran
%A Barr, Lorna
%A Baumes, Jeffrey M.
%A DiVittorio, Kristy M.
%A Johnson, James R.
%A Noll, Bruce C.
%A Smith, Bradley D.
%D 2007
%T Self-Assembly of Fluorescent Inclusion Complexes in
Competitive Media Including the Interior of Living Cells
%U https://acs.figshare.com/articles/media/Self_Assembly_of_Fluorescent_Inclusion_Complexes_in_Competitive_Media_Including_the_Interior_of_Living_Cells/2971057
%R 10.1021/ja075567v.s004
%2 https://acs.figshare.com/ndownloader/files/4670329
%K squaraine dyes
%K inclusion complexes
%K Competitive Media
%K assembly process
%K squaraine dye
%K macrocycle amide NH residues
%K Squaraine encapsulation
%K squaraine oxygens
%K vesicle membranes
%K isophthalamide units associates
%K building blocks
%K chloroform 400 000 times
%K log Ka
%K imaging probes
%K cell localization propensities
%K binding partners
%K 400 000
%K Fluorescent Inclusion Complexes
%K chemical stabilities
%X Anthracene-containing tetralactam macrocycles are prepared and found to have an extremely
high affinity for squaraine dyes in chloroform (log Ka = 5.2). Simply mixing the two components produces
highly fluorescent, near-infrared inclusion complexes in quantitative yield. An X-ray crystal structure shows
the expected hydrogen bonding between the squaraine oxygens and the macrocycle amide NH residues,
and a high degree of cofacial aromatic stacking. The kinetics and thermodynamics of the assembly process
are very sensitive to small structural changes in the binding partners. For example, a macrocycle containing
two isophthalamide units associates with the squaraine dye in chloroform 400 000 times faster than an
analogous macrocycle containing two 2,6-dicarboxamidopyridine units. Squaraine encapsulation also occurs
in highly competitive media such as mixed aqueous/organic solutions, vesicle membranes, and the
organelles within living cells. The highly fluorescent inclusion complexes possess emergent properties;
that is, as compared to the building blocks, the complexes have improved chemical stabilities, red-shifted
absorption/emission maxima, and different cell localization propensities. These are useful properties for
new classes of near-infrared fluorescent imaging probes.
%I ACS Publications