Proximity effects. 2. Conformational influence of nonacyl groups on acyl group properties in N-monosubstituted amides and in other carboxylic acid derivatives: a 7-position proximity effect

Thermodynamic properties of (an ester+an alkane). XVI. Experimental HmE and VmE values and a new correlation method for (an alkyl ethanoate+an n-alkane) at 318.15 K

“…Finally, there seems to be an equilibrium between the intermolecular association by the hydrogen bridge and the intramolecular association due to the formation of cycles with seven members, see figure 6, in the IR spectroscopy studies of Dusart et al [17]. Other NMR studies [18] of amides also suggest the same. However, it would be difficult for these weak intramolecular hydrogen bridges to compensate for the rupture of the Van der Waals attractions generated between the hydrocarbon chains in zig-zag and quasiparallel.…”

Thermodynamic properties of (a butyl ester + an -alkane). XIII. and for {}, where= 1 to 3 and= 1 to 7

“…The results of n.m.r. studies (19) have also been indicative of effects along those same lines. However, weak intramolecular hydrogen bonds are unlikely to be able to offset the breakdown in the van der Waals attractions arising between hydrocarbon chains organized in a quasi-parallel zig-zag arrangement (see figure 3).…”

Induced 13C shifts by coil‐supporting solvents observed in oligopeptides as model compounds of polypeptides

“…1 , 2 for the dipeptide 1 and tripeptide 2, respectively. The N T , value for the C"(1) of the dipeptide in CDCb at 76 "C to 29 "C (B/A), and in MezSO at 29 "C relative to that in CDC13 at 29 "C (C/A) is larger in NT, in s CDCI,, 29 both cases than the corresponding ratios for C"(2). b, 0,4 M for the dipeptide, 0,3 M for the tripeptide.…”