A New Quadruply Bound Heterodimer DDAD·AADA and Investigations into the Association Process

Abstract

DDAD·AADA heterodimers based on the structures 8 and 9 have been synthesised and characterised. Solubility problems have been overcome through the introduction of a 2,6‐dimethylphenyl substituent (8c), and association constants Kass have been determined by 1H NMR titrations. The Kass values obtained could be confirmed by osmometry, as could the association constants for other heterodimers. The Kass value increases when the acidity of participating N−H hydrogen atoms is enhanced. (© Wiley‐VCH Verlag GmbH, 69451 Weinheim, Germany, 2002)

Polyurea–Urethane Supramolecular Thermo-Reversible Networks

“…Actually these results indicate that zigzag conformation is predominant for the various PU while folded intramolecular interaction is predominant for PU Bi (Figure ). Equivalent results were also reported in literature for systems with more than four hydrogen bond moieties. − …”

Polyurea–Urethane Supramolecular Thermo-Reversible Networks

“…Actually these results indicate that zigzag conformation is predominant for the various PU while folded intramolecular interaction is predominant for PU Bi (Figure ). Equivalent results were also reported in literature for systems with more than four hydrogen bond moieties. − …”

With Regard to the Hydrogen Bonding in Complexes of Pyridylureas, Less Is More. A Role for Shape Complementarity and CH···O Interactions?

“…The 4-methyl group Folded structure of 2 and hydrogen-bonded complex 1‚2 with K assoc reported by Lu ¨ning. 6 In the present study, the value K assoc ) 180 ( 25 M -1 was determined, which is acceptably close to the reported value. plays only a minor role as N-butyl-N′-(pyridin-2-yl)urea (6) gave K assoc ) 393 M -1 (single determination).…”

“…Folded structure of 2 and hydrogen-bonded complex 1 · 2 with K assoc reported by Lüning . In the present study, the value K assoc = 180 ± 25 M -1 was determined, which is acceptably close to the reported value.…”

“…Herein, we report solution- and solid-state studies on 1 , 2 , and related compounds that provide insight into their unusual complexation chemistry.

1 Folded structure of 2 and hydrogen-bonded complex 1 · 2 with K assoc reported by Lüning . In the present study, the value K assoc = 180 ± 25 M -1 was determined, which is acceptably close to the reported value.

…”

Urea-Functionalized Heterocycles: Structure, Hydrogen Bonding and Applications

“…Zimmerman studied pyridyl-urea derivatives with DDA binding motifs (19, Figure 7) [5,44]. The association constant of the complex held together by three hydrogen bonds (19:20) was rather small, as was expected.…”

Polyurea–Urethane Supramolecular Thermo-Reversible Networks

“…Actually these results indicate that zigzag conformation is predominant for the various PU while folded intramolecular interaction is predominant for PU Bi (Figure ). Equivalent results were also reported in literature for systems with more than four hydrogen bond moieties. − …”

With Regard to the Hydrogen Bonding in Complexes of Pyridylureas, Less Is More. A Role for Shape Complementarity and CH···O Interactions?

“…The 4-methyl group Folded structure of 2 and hydrogen-bonded complex 1‚2 with K assoc reported by Lu ¨ning. 6 In the present study, the value K assoc ) 180 ( 25 M -1 was determined, which is acceptably close to the reported value. plays only a minor role as N-butyl-N′-(pyridin-2-yl)urea (6) gave K assoc ) 393 M -1 (single determination).…”

“…Folded structure of 2 and hydrogen-bonded complex 1 · 2 with K assoc reported by Lüning . In the present study, the value K assoc = 180 ± 25 M -1 was determined, which is acceptably close to the reported value.…”

“…Herein, we report solution- and solid-state studies on 1 , 2 , and related compounds that provide insight into their unusual complexation chemistry.

1 Folded structure of 2 and hydrogen-bonded complex 1 · 2 with K assoc reported by Lüning . In the present study, the value K assoc = 180 ± 25 M -1 was determined, which is acceptably close to the reported value.

…”

Urea-Functionalized Heterocycles: Structure, Hydrogen Bonding and Applications

“…Zimmerman studied pyridyl-urea derivatives with DDA binding motifs (19, Figure 7) [5,44]. The association constant of the complex held together by three hydrogen bonds (19:20) was rather small, as was expected.…”

Polyurea–Urethane Supramolecular Thermo-Reversible Networks

“…Actually these results indicate that zigzag conformation is predominant for the various PU while folded intramolecular interaction is predominant for PU Bi (Figure ). Equivalent results were also reported in literature for systems with more than four hydrogen bond moieties. − …”

With Regard to the Hydrogen Bonding in Complexes of Pyridylureas, Less Is More. A Role for Shape Complementarity and CH···O Interactions?

“…The 4-methyl group Folded structure of 2 and hydrogen-bonded complex 1‚2 with K assoc reported by Lu ¨ning. 6 In the present study, the value K assoc ) 180 ( 25 M -1 was determined, which is acceptably close to the reported value. plays only a minor role as N-butyl-N′-(pyridin-2-yl)urea (6) gave K assoc ) 393 M -1 (single determination).…”

“…Folded structure of 2 and hydrogen-bonded complex 1 · 2 with K assoc reported by Lüning . In the present study, the value K assoc = 180 ± 25 M -1 was determined, which is acceptably close to the reported value.…”

“…Herein, we report solution- and solid-state studies on 1 , 2 , and related compounds that provide insight into their unusual complexation chemistry.

1 Folded structure of 2 and hydrogen-bonded complex 1 · 2 with K assoc reported by Lüning . In the present study, the value K assoc = 180 ± 25 M -1 was determined, which is acceptably close to the reported value.

…”

Urea-Functionalized Heterocycles: Structure, Hydrogen Bonding and Applications

“…Zimmerman studied pyridyl-urea derivatives with DDA binding motifs (19, Figure 7) [5,44]. The association constant of the complex held together by three hydrogen bonds (19:20) was rather small, as was expected.…”