Active Role of Water in the Hydration of Macromolecules with Ionic End Group for Hydrophobic Effect-Caused Assembly

Abstract

The role of water in the hydration and aqueous assembly of hydrophobic P+X– (P+: macromolecular phosphonium cation, X–: anion) was investigated via complementary Fourier transform infrared (FT-IR) and low-field NMR analyses. The hydration of the macromolecular backbone was dependent on X–. When X– is I–, the ionic end group ordered water molecules that exerted a detectable long-range effect of dehydrating the backbone. The consequent hydrophobic interaction drove the aqueous assembly of P+I– into micelle-like aggregates, with the ionic group exposed to water. In contrast, the ion pair with a hydrophobic anion of [BPh4]− was not able to hold water and did not deplete the hydration water. The hydrated backbone endowed the assembly of P+[BPh4]− into vesicles that were driven by hydration interactions. This elucidation at the molecular level is craved to progress the aqueous supramolecular chemistry.

The effect of hydration and dehydration on the conformation, assembling behavior and photoluminescence of PBLG

“…This indicates that the orientation for C–O–C groups is regulated resulting from dehydration-caused contraction of PBLG. 51–53 This analysis is in line with the absorptions due to CH 2 groups and phenyl rings. The CH 2 stretching absorption has a shift from 2975 cm −1 to 2982 cm −1 (Fig.…”

Moisture variation analysis of the green plum during the drying process based on low‐field nuclear magnetic resonance

“…We used simultaneous iterative reconstruction 100,000 for inversion to obtain the relaxation map of the green plum samples. Finally, the transverse relaxation spectra of the samples were obtained by multi‐index fitting using MultiExp LNV analysis software (Suzhou Niumag Analytical Instrument Co.) (He et al., 2020).…”

Aqueous Self-Assembly of Hydrophobic Molecules Influenced by the Molecular Geometry

“…The hydration of the polar carbonyl and imine groups in the molecules could be a reason for colloidal stability, so we examined this possibility by Fourier transform infrared spectroscopy (FT-IR) analysis. − As shown in Figure S3, the increase in the water content does not shift the absorbance peak of the carbonyl (1661 and 1698 cm –1 ) and imine group (1595 cm –1 ) in POSS-PDI-POSS and C 12 -PDI-C 12 . This result indicates that the imine group does not tend to hydration in this condition and the polar groups do not play a vital role in the aqueous behavior of these two molecules.…”

“…Water takes part in biological assembling processes, which has constructional roles in addition to acting as a solvent. , Hydrophobic molecules can be hydrated, known as hydrophobic hydration, but the hydration water can be easily repelled resulting in the hydrophobic collapse. − This is the conventional concept of hydrophobic effects (HE). , Guided by this effect, most building blocks used for aqueous self-assembly are amphiphiles and require water-soluble groups to maintain the suspension of the assembles in water . However, proteins and synthetic hydrophobic molecules − without water-soluble groups are also able to undergo aqueous self-assembly, which usually trap water within the assemblies. − The trapped inner water was found to be crucial for the colloidal stability. ,− …”