The growing realization that photoinduced bending of slender photoreactive single crystals is surprisingly common has inspired researchers to control crystal motility for actuation. However, new mechanically responsive are reported at a greater rate than their quantitative photophysical characterization; identification measurable parameters and molecular-scale factors determine the mechanical response yet be established. Herein, simple mathematical description quasi-static time-dependent...

The range of unit cell orientations generated at the kink a bent single crystal poses unsurmountable challenges with diffraction analysis and limits insight into molecular-scale mechanism bending. On plastically hexachlorobenzene, it is demonstrated here that spatially resolved microfocus infrared spectroscopy using synchrotron radiation can be applied in conjunction periodic density functional theory calculations to predict spectral changes or extract information on structural occur as...

Potential energy hypersurfaces (PESs) for four fluoroform complexes (with acetonitrile, ethyleneoxide, formaldehyde, and water) were explored at the HF, MP2, B3LYP/6-311++G(d,p) levels of theory. Anharmonic C–H stretching vibrational frequency shifts are reported all minima located on studied PESs. In cases, lowest-energy minimum occurs a C–H⋯O(N) hydrogen-bonded arrangement is characterized by significant blueshift (upshift), while additional [for “reversed” orientations, in which there no...

Molecular dynamics and electric field strength simulations are performed in order to quantify the structural, dynamic, vibrational properties of non-H-bonded (dangling) OH groups hydration shell neopentane, as well bulk water. The results found be good agreement with experimentally observed high-frequency (∼3660 cm−1) band arising from neopentanol dissolved HOD/D2O, obtained by analyzing variable concentration Raman spectra using multivariate curve resolution (Raman-MCR). simulation further...

This study provides in-depth insights into the thermodynamics of electrochemical processes that govern generation and temporal modulation open-circuit potentials in biofilms presents foundation applications potential methods to bioelectrochemical behaviors biofilms. investigation was guided by an overarching hypothesis models should adequately explain patterns generated when environmental conditions change; from this work, a generalized model endemic biofilm electrode developed validated....

The melting of any pure crystalline material at constant pressure is one its most fundamental properties, and it has been used to identify organic compounds or verify their chemical phase purity since the early times chemistry. Here, we report that a mechanical deformation plastic single crystals such as bending results in small yet significant decrease point about 0.3–0.4 K. bent section crystal was found be mechanically softer relative straight sections, softening temperature preceding...

The average OH stretching vibrational frequency for the water molecules in first hydration shell around a Li(+) ion dilute aqueous solution was calculated by hybrid molecular dynamics + quantum-mechanical ("MD QM") approach. Using geometry configurations from series of snapshots an MD simulation, anharmonic, uncoupled frequencies were 100 first-shell oscillators at B3LYP and HF/6-31G(d,p) levels theory, explicitly including relevant second into charge-embedded supermolecular QM calculations....

The controlled introduction of defects into MOFs is a powerful strategy to induce new physiochemical properties and improve their performance for target applications. Herein, we present defect formation amorphization the canonical MOF-74 frameworks based on fine-tuning adsorbate-framework interactions in metal congener, hence introducing structural defects. Specifically, demonstrate that between MOF bidentate ligands adsorbed pores initiates eventual crystal. These features unlock are...

The electronic structure and thermochemical stability of the HOX-SO(3) (X = F, Cl, Br) complexes is studied using second-order Møller-Plesset perturbation theory (MP2). calculated dissociation energies HOF-SO(3), HOCl-SO(3), HOBr-SO(3) are 5.43, 6.02, 5.98 kcal mol(-1) at MP2/6-311++G(3df,3pd) level, respectively. Anharmonic OH stretching frequencies HOX moieties along with frequency shifts upon complex formation MP2/6-311++G(2df,2p) level. AIM NBO analyses were also performed. Theoretical...

The anharmonic OH stretching vibrational frequencies, ν(OH), for the first-shell water molecules around Li+, Ca2+, Mg2+, and Al3+ ions in dilute aqueous solutions have been calculated based on classical molecular dynamics (MD) simulations quantum-mechanical (QM) calculations. For Li+(aq), Ca2+(aq), Mg2+(aq), Al3+(aq), our IR frequency shifts, Δν(OH), with respect to gas-phase frequency, are about −300, −350, −450, −750 cm−1, compared −290, −420, −830 cm−1 from experimental infrared (IR)...