Two supramolecular compounds constructed by polyacid anion clusters: Synthesis, characterization and performance research

In this paper, two novel organic-inorganic hybrid supramolecule compounds {[Cu·L1’·H2O]·(α-Mo8O26)0.5}n 1 and compound {[Cu·L2’·H2O]·(α-Mo8O26)0.5}n 2 have been synthesized [L1’ = 1, 3-bis (4-carboxylpyridine) propane dibromide, L2’ = 1, 4-bis (4-carboxylpyridine) butane dibromide]. Compounds 1 and 2 have been expressly confirmed by PXRD, IR, X-ray single crystal diffraction and TG. Last, the study found that compounds 1 and 2 have obvious adsorption effects on MB and RhB organic dyes, and compound 2 has high adsorption capacity for MB.

Determinants for proton location and electron coupled proton transfer in hydrogen bonded pentafluorophenol–anion clusters

This work reveals the determinant factors for proton locations and electron coupled proton transfer (ECPT) in biologically relevant hydrogen bonded systems.

The role of H₂SO₄-NH₃ anion clusters in ion-induced aerosol nucleation mechanisms in the boreal forest

New particle formation (NPF) provides a large source of atmospheric aerosols, which affect the climate and human health. In recent chamber studies, ion-induced nucleation (IIN) has been discovered as an important pathway of forming particles; however, atmospheric investigation remains incomplete. For this study, we investigated the air anion compositions in the boreal forest in southern Finland for three consecutive springs, with a special focus on H2SO4-NH3 anion clusters. We found that the ratio between the concentrations of highly oxygenated organic molecules (HOMs) and H2SO4 controlled the appearance of H2SO4-NH3 clusters (3<no.S<13): all such clusters were observed when [HOM] ∕ [H2SO4] was smaller than 30. The number of H2SO4 molecules in the largest observable cluster correlated with the probability of ion-induced nucleation (IIN) occurrence, which reached almost 100 % when the largest observable cluster contained six or more H2SO4 molecules. During selected cases when the time evolution of H2SO4-NH3 clusters could be tracked, the calculated ion growth rates exhibited good agreement across measurement methods and cluster (particle) sizes. In these cases, H2SO4-NH3 clusters alone could explain ion growth up to 3 nm (mobility diameter). IIN events also occurred in the absence of H2SO4-NH3, implying that other NPF mechanisms also prevail at this site, most likely involving HOMs. It seems that H2SO4 and HOMs both affect the occurrence of an IIN event, but their ratio ([HOMs] ∕ [H2SO4]) defines the primary mechanism of the event. Since that ratio is strongly influenced by solar radiation and temperature, the IIN mechanism ought to vary depending on conditions and seasons.

The role of H₂SO₄-NH₃ anion clusters in ion-induced aerosol nucleation mechanisms in the boreal forest

New particle formation (NPF) provides a large source of atmospheric aerosols, which affect the climate and human health. Ion-induce nucleation (IIN) has been discovered as an important pathway of forming particles within recent chamber studies, however, atmospheric investigation remains incomplete. For this study, we investigated the air anion compositions in the boreal forest in Southern Finland for 3 consecutive springs, with a special focus on H2SO4-NH3 anion clusters. We found that the ratio between the concentrations of highly oxygenated organic molecules (HOMs) and H2SO4 controlled the appearance of H2SO4-NH3 clusters (#S > 3): All such clusters were observed when [HOM] / [H2SO4] was smaller than 30. The number of H2SO4 molecules in the largest observable cluster correlated with the probability of ion-induced nucleation (IIN) occurrence, which reached almost 100 % when the largest observable cluster contained 6 or more H2SO4 molecules. During selected cases when the time evolution of H2SO4-NH3 clusters could be tracked, the calculated ion growth rates exhibited a good agreement across measurement methods and cluster (particle) sizes. In these cases, H2SO4-NH3 clusters alone could explain ion growth up to 3 nm (mobility diameter). IIN events also occurred in the absence of H2SO4-NH3, implying that also other NPF mechanisms prevail at this site, most likely involving HOMs. It seems that H2SO4 and HOMs both affect the occurrence of an IIN event, but their ratio ([HOMs] / [H2SO4]) defines the primary mechanism of the event. Since that ratio is strongly influenced by solar radiation and temperature, IIN mechanism ought to vary depending on conditions and seasons.

Effect of High Salt Concentration on Ion Clustering and Transport in Polymer Solid Electrolytes: a Molecular Dynamics Study of PEO-LiTFSI

<div> <div> <div> <p>The model and analysis methods developed in this work are generally applicable to any polymer electrolyte/cation-anion combination, but we focus on the currently most prominent polymer electrolyte material system: poly(ethylene) oxide/Li- bis(trifluoromethane) sulfonamide (PEO + LiTFSI). The obtained results are surprising and challenge the conventional understanding of ionic transport in polymer electrolytes: the investigation of a technologically relevant salt concentration range (1 - 4 M) revealed the central role of the anion in coordinating and hindering Li ion movement. Our results provide insights into correlated ion dynamics, at the same time enabling rational design of better PEO-based electrolytes. In particular, we report the following novel observations. 1. Strong binding of the Li cation with the polymer competes with significant correlation of the cation with the salt anion. 2. The appearance of cation-anion clusters, especially at high concentration. 3. The asymmetry in the composition (and therefore charge) of such clusters; specifically, we find the tendency for clusters to have a higher number of anions than cations.</p> </div> </div> </div>