Host-guest chemistry. 14. Solvent and salt effects on binding constants of organic substrates in macrocyclic host compounds. A general equation measuring hydrophobic binding contributions

Abstract

Also, two minor isomers were detected 6 3.07 (dt, J = 10, 2.5 Hz) and 6 3.31 (dm, J = I O Hz) in a 95.1:2.6:2.3 ratio. (la,2cr,3a)-N-Methyl-6-isopropylidene-3-propy~-4-cyclohexen~l,2dicarboximide: 'H NMR (CDC13, 200 MHz) 6 0.95 (t, J = 7.2 Hz, 3 H), 1.43-1.89 (m, 4 H), 1.91 (s, 3 H), 2.00 (s, 3 H), 2.29 (m, 1 H), 2.79 ,925,905, 840,790,735 cm-l; MS, m / e 364, 320, 308, 211. (la,2cr,3a)-N-Methyl-S-( tert -butyldimethylsiloxy)-6-isopropylidene-3-propyl-4-cyclohexene-l,2-carboximide: IH NMR (CDC13, 200 MHz) 1.30-1.86 (m. 4 H), 1.96 (s, 3 H), 2.13 (m, 1 H), 2.86 (s, 3 H), 3.06 (dd,

Structural Effects on the Stability of Some Hydrogen‐Bonded Complexes with Nucleobases

“…[5] The more recent quantification of ∆G cplx with two scribed earlier. [9] In all cases the NH shifts showed the largadditive increments, [6] one for the primary hydrogen bond est change, of up to 7 ppm in the dilution experiments with the other for the secondary interaction, is in line with exper4a and 6, and 4.8 ppm with the host-guest pairs. In some imental results from a impressive series of such host-guest cases other NMR signals, such as 6-CH, 5-CH 3 and CH 3 complexes.…”

“…din-1-yl)] Derivatives 4: [18] 9,128.7,127.8,9.22,N 19.86;found C 59.88,H 8.79, 68.39, H 8.81, N 14.51; found C 68.45, H 8.72, N 14.35. 280°C (decomp. …”

“…The binding studies showed that receptors with both rigid (4a) and flexible spacers (4b,4c) have low binding constants with 9-ethyladenine ( Table 2). We attribute these poor binding 80% complexation performed as described earlier [9] using Sigmaplot 5.0 (Jandel Scientific). THF was purified before use (by refluxing with sodium/benzophenone) and distilled immediately before use.…”

Stabilities of Hydrogen-Bonded Supramolecular Complexes with Various Numbers of Single Bonds: Attempts To Quantify a Dogma in Host-Guest Chemistry

“…Equilibrium constants were determined according to ref. [11] and gave a satisfactory fit to a 1:1 model for the association between host and guest monomers (e.g., Figure 1). The spacers were chosen to allow contact between the corresponding binding sites without buildup of substantial strain; this was checked by computer-aided molecular modeling ( Figure 2).…”

Hydrogen bonding association of a ruthenium(II) bipyridine barbituric acid guest to complementary 2,6-diaminopyridine amide hosts: guidelines for designing high binding hydrogen bonding cavities in both high-and low-polarity solvents

“…Fluorescence methods were used mainly in CH 2 Cl 2 , where the large binding constants observed required the use of low concentrations of RuG2 and host molecules. 13 A typical example of a large binding constant is shown for the host CF 3 /H where the fluorescence intensity of RuG2 increases upon the addition of host CF 3 /H (as R/X) in CH 2 Cl 2 (Fig. 2).…”