TY - JOUR
T1 - Competitive pi-stacking and H-bond piling increase solubility of heterocyclic redoxmers
AU - Zhao, Yuyue
AU - Sarnello, Erik S.
AU - Robertson, Lily A.
AU - Zhang, Jingjing
AU - Shi, Zhangxing
AU - Yu, Zhou
AU - Bheemireddy, Sambasiva R.
AU - Z, Y
AU - Li, Tao
AU - Assary, Rajeev S.
AU - Cheng, Lei
AU - Zhang, Zhengcheng
AU - Zhang, Lu
AU - Shkrob, Ilya A.
N1 - Funding Information:
This work was supported as part of the Joint Center for Energy Storage Research (JCESR), an Energy Innovation Hub funded by the U.S. Department of Energy, Office of Science, Basic Energy Sciences. The submitted manuscript has been created by UChicago Argonne, LLC, Operator of Argonne National Laboratory (“Argonne”). Argonne, a U.S. Department of Energy Office of Science laboratory, is operated under contract no. DE-AC02-06CH11357. The U.S. Government retains for itself, and others acting on its behalf, a paid-up nonexclusive, irrevocable worldwide license in said article to reproduce, prepare derivative works, distribute copies to the public, and perform publicly and display publicly, by or on behalf of the Government.
Publisher Copyright:
© 2020 American Chemical Society.
PY - 2020/11/19
Y1 - 2020/11/19
N2 - Redoxmers are organic molecules that carry electric charge in flow batteries. In many instances, they consist of heteroaromatic moieties modified with appended groups to prevent stacking of the planar cores and increase solubility in liquid electrolytes. This higher solubility is desired as it potentially allows achieving greater energy density in the battery. However, the present synthetic strategies often yield bulky molecules with low molarity even when they are neat and still lower molarity in liquid solutions. Fortunately, there are exceptions to this rule. Here, we examine one well-studied redoxmer, 2,1,3-benzothiadiazole, which has solubility ∼5.7 M in acetonitrile at 25 °C. We show computationally and prove experimentally that the competition between two packing motifs, face-to-face π-stacking and random N−H bond piling, introduces frustration that confounds nucleation in crowded solutions. Our findings and examples from related systems suggest a complementary strategy for the molecular design of redoxmers for high energy density redox flow cells.
AB - Redoxmers are organic molecules that carry electric charge in flow batteries. In many instances, they consist of heteroaromatic moieties modified with appended groups to prevent stacking of the planar cores and increase solubility in liquid electrolytes. This higher solubility is desired as it potentially allows achieving greater energy density in the battery. However, the present synthetic strategies often yield bulky molecules with low molarity even when they are neat and still lower molarity in liquid solutions. Fortunately, there are exceptions to this rule. Here, we examine one well-studied redoxmer, 2,1,3-benzothiadiazole, which has solubility ∼5.7 M in acetonitrile at 25 °C. We show computationally and prove experimentally that the competition between two packing motifs, face-to-face π-stacking and random N−H bond piling, introduces frustration that confounds nucleation in crowded solutions. Our findings and examples from related systems suggest a complementary strategy for the molecular design of redoxmers for high energy density redox flow cells.
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U2 - 10.1021/acs.jpcb.0c07647
DO - 10.1021/acs.jpcb.0c07647
M3 - Article
C2 - 33158362
AN - SCOPUS:85096456567
SN - 1520-6106
VL - 124
SP - 10409
EP - 10418
JO - Journal of Physical Chemistry B
JF - Journal of Physical Chemistry B
IS - 46
ER -