%0 Generic
%A Qiao, Bo
%A Hirsch, Brandon E.
%A Lee, Semin
%A Pink, Maren
%A Chen, Chun-Hsing
%A Laursen, Bo W.
%A Flood, Amar H.
%D 2017
%T Ion-Pair
Oligomerization of Chromogenic Triangulenium
Cations with Cyanostar-Modified Anions That Controls Emission in Hierarchical
Materials
%U https://acs.figshare.com/articles/dataset/Ion-Pair_Oligomerization_of_Chromogenic_Triangulenium_Cations_with_Cyanostar-Modified_Anions_That_Controls_Emission_in_Hierarchical_Materials/4905635
%R 10.1021/jacs.7b01937.s002
%2 https://acs.figshare.com/ndownloader/files/8248046
%K BF
%K receptor-modified counteranions
%K sandwich complexes
%K material
%K Hierarchical Materials
%K Chromogenic Triangulenium Cations
%K structure coevolves
%K assembly
%K solution assemblies
%K π- contact
%K chromogenic trioxatriangulenium
%K Ion-Pair Oligomerization
%K ion pair
%K red-shifted emission
%K CS
%K cationic molecules
%K Controls Emission
%K cyanostar
%K emission properties
%K TOTA
%K cation stacks
%K ion pairs oligomerize
%K Cyanostar-Modified Anions
%K red-shifted features
%K absorption bands
%X The hierarchical
assembly of colored cationic molecules with receptor-modified
counteranions can be used to control optical properties in materials.
However, our knowledge of when the optical properties emerge in the
hierarchical organization and the variety of cation–anion salts
that are available to create these materials is limited. In this work,
we extend the salts from small halides to large inorganic anions and
determine how the structure coevolves with the emission properties
using solution assemblies. We study the chromogenic trioxatriangulenium
(TOTA+) cation and its coassembly with cyanostar
(CS) macrocycles selected to modify tetrafluoroborate
(BF4–) counteranions through formation
of 2:1 sandwich complexes. In the solid state, the TOTA+ cation stacks in an alternating manner with the sandwich
complexes producing new red-shifted emission and absorption bands.
Critical to assigning the structural origin of the new optical features
across the four levels of organization (1° → 4°)
is the selection of specific solvents to produce and characterize
different assemblies present in the hierarchical structure. A key
species is the electrostatically stabilized ion pair between the TOTA+ cation and sandwich complex. The red-shifted
features only emerge when the ion pairs oligomerize together into
larger (TOTA·[CS2BF4])n assemblies. New electronic
states emerge as a result of multiple copies of the TOTA+ making π-contact with cyanostar–anion complexes.
Our findings and the ease with which the materials can be prepared
as crystals and films by mixing the salt with a receptor provide a
strong platform for the de novo design of new optical
materials.
%I ACS Publications