Assessment of the VDW interaction converting DMAPS from the thermal-motion form to the hydrogen-bonded form

Abstract

Assessment of van der Waals (VDW) interactions is fundamental to all of the central quest of structure that regulates the biological function. VDW interactions contributing to intramolecular weak hydrogen bonding are regarded as an important force to regulate the thermal stimuli-sensitive function of sulfobetaine methacrylate, DMAPS. We present here the conversion from the thermal-motion form at room temperature to the weak-hydrogen-bonded form against thermal motion as a terahertz spectral change with a definite isosbestic point from an absorption peak of one form to the other. Vibrational absorptions are used as a probe for assessing VDW interactions in conjunction with highly reliable and well-established density functional theory (DFT) calculations for analysis. Complicated spectral features and uncertain conformations of DMAPS in the amorphous state are clearly resolved under the polarizable continuum model and the dispersion correction for the pure DFT calculations.

Internalization Mechanisms of Pyridinium Sulfobetaine Polymers Evaluated by Induced Protic Perturbations on Cell Surfaces

“…Some CPPs use lipid rafts for nonendocytic cellular uptake. − , Moreover, the translocation mechanisms depend on the differences in the molecular structures of the four polysulfobetaines (Scheme ). Simple aliphatic P­(DMAPS) aggregates are formed by dipole–dipole and hydrophobic interactions between the intra/inter-polymer chains . Hydrophobic association with the lipid bilayer core is attributed to the inner salt formation of the sulfobetaine moiety in P­(DMAPS).…”

“…Simple aliphatic P-(DMAPS) aggregates are formed by dipole−dipole and hydrophobic interactions between the intra/inter-polymer chains. 48 Hydrophobic association with the lipid bilayer core is attributed to the inner salt formation of the sulfobetaine moiety in P(DMAPS). P(ePySMAAm) and P(mPySMAAm) have π−π, NH−π, and cation−π interactions between the pyridyl sulfobetaine and methacrylamide chains.…”

Effective screening of medium-assisted van der Waals interactions between embedded particles

“…29 From the viewpoint of an implicit approach such as the PCM, these corrections are based on free-particle interactions disregarding the presence of the environment. While appropriate in case that both interacting particles are within the same cavity, 30 this approach disregards screening by an implicit environment. It was therefore suggested to scale the van der Waals contributions by ε −2 (ω) with ω in an optical range.…”

Temperature-Dependent Low-Frequency Vibrations of Thiamine Crystal Containing Hydrated Ions

“…We reveal the local environment of hydrated ions in the crystal from the temperature-dependent behavior of weak hydrogen bonds connected to hydration water and two chloride ions under the hydrogen-bonded network. In our previous study, we found, using synchrotron Fourier transform infrared (FTIR) microspectroscopy and THz spectroscopy, that a remarkable temperature-dependent spectral change occurs around 300 cm – 1 and is related to the thermal cleavage of weak hydrogen bonds at the van der Waals limit . Since the previous study was an amorphous system, the molecular conformation was unknown and deduced from the matching of calculated and observed spectral patterns.…”