Thermodynamic and electrochemical study of tailor-made crown ethers for redox-switchable (pseudo)rotaxanes

• Henrik Hupatz,
• Marius Gaedke,
• Hendrik V. Schröder,
• Julia Beerhues,
• Arto Valkonen,
• Fabian Klautzsch,
• Sebastian Müller,
• Felix Witte,
• Kari Rissanen,
• Biprajit Sarkar and
• Christoph A. Schalley

Beilstein J. Org. Chem. 2020, 16, 2576–2588, doi:10.3762/bjoc.16.209

• ]. Consequently, we chose to use a resorcinol-connected crown ether motif introduced by Stoddart and co-workers [44] for the NDI-crown-8 NDIC8 (Figure 1). To compare the larger crown ethers with smaller analogs, benzo-21-crown-7 (BC7) and the derivatives were also included, as at least the parent compound forms

Self-assembly behaviors of perylene- and naphthalene-crown macrocycle conjugates in aqueous medium

• Xin Shen,
• Bo Li,
• Tiezheng Pan,
• Jianfeng Wu,
• Yangxin Wang,
• Jie Shang,
• Yan Ge,
• Lin Jin and
• Zhenhui Qi

Beilstein J. Org. Chem. 2019, 15, 1203–1209, doi:10.3762/bjoc.15.117

• Materials & Engineering (IBME), Northwestern Polytechnical University, Xi’an, Shaanxi 710072, P. R. China 10.3762/bjoc.15.117 Abstract The synthesis of conjugates of perylene diimide (PDI) and naphthalene diimide (NDI) modified with two benzo-21-crown-7 ethers (B21C7) are herein described. Their self

• ]. However, we recently found that benzo-21-crown-7 (B21C7) displays impressive high water solubility in comparison with other macrocyclic hosts [55]. Moreover, the conjugation of B21C7s to the well-known supramolecular BTA core leads to the observation of special topological effects on ion selectivity in

LCST phase behavior of benzo-21-crown-7 with different alkyl chains

• Yan Deng,
• Xing Li,
• Qiao Zhang,
• Zheng Luo,
• Chengyou Han and
• Shengyi Dong

Beilstein J. Org. Chem. 2019, 15, 437–444, doi:10.3762/bjoc.15.38

• previous work, we have found that benzo-21-crown-7 (B21C7) and its derivatives exhibit typical LCST behavior in water, and that different substituted groups exert a great influence on the thermo-responsiveness [39]. However, highly concentrated solutions (>120 mg/mL) of B21C7s and elevated temperatures

• .15.38 Abstract The introduction of hydrophobic units into crown ethers can dramatically decrease the critical transition temperature of LCST and realize macroscopic phase separation at low to moderate temperature and concentration. Minor modifications in the chemical structure of crown ethers (benzo-21

• -crown-7, B21C7s) can effectively control the thermo-responsive properties. Keywords: crown ethers; hydrophobic units; lower critical solution temperature; LCST; thermo-responsiveness; supramolecular chemistry; Introduction The introduction of stimuli-responsiveness into artificial materials is vital

Complexation of molecular clips containing fragments of diphenylglycoluril and benzocrown ethers with paraquat and its derivatives

• Leonid S. Kikot',
• Catherine Yu. Kulygina,
• Alexander Yu. Lyapunov,
• Svetlana V. Shishkina,
• Roman I. Zubatyuk,
• Tatiana Yu. Bogaschenko and
• Tatiana I. Kirichenko

Beilstein J. Org. Chem. 2017, 13, 2056–2067, doi:10.3762/bjoc.13.203

• . The stability constants with paraquat (7) rise with the increase of the polyether cycle size. The maximum complementarity of the pseudo cavity for binding of paraquat (7) was observed for clips based on benzo-21-crown-7 and benzo-24-crown-8. The introduction of substituents with terminal OH groups on

Templated versus non-templated synthesis of benzo-21-crown-7 and the influence of substituents on its complexing properties

• Wei Jiang and
• Christoph A. Schalley

Beilstein J. Org. Chem. 2010, 6, No. 14, doi:10.3762/bjoc.6.14

• Wei Jiang Christoph A. Schalley Institut für Chemie und Biochemie, Freie Universität Berlin, Takustraße 3, 14195 Berlin, Germany 10.3762/bjoc.6.14 Abstract Two procedures for the synthesis of benzo-21-crown-7 have been explored. The [1+1] macrocyclization with KBF4 as the template was found to be

• more efficient than the intramolecular macrocyclization without template. Pseudorotaxanes form with secondary ammonium ions bearing at least one alkyl chain narrow enough to slip into the crown ether. Substitution on benzo-21-crown-7 or on the secondary ammonium axle alters the binding affinity and

• binding mode. Compared to dibenzo-24-crown-8, the complexing properties of benzo-21-crown-7 turn out to be more susceptible to modifications at the crown periphery. Keywords: benzo-21-crown-7; pseudorotaxane; self-sorting; supramolecular chemistry; template; Introduction Mechanically interlocked