Molecular dynamics simulations were performed to observe the evolution of cagelike water clusters immersed in bulk liquid water at 250 and 230 K. Totally, we considered four types of clusters--dodecahedral (5(12)) and tetrakaidecahedral (5(12)6(2)) cagelike water clusters filled with or without a methane molecule, respectively. The lifetimes of these clusters were calculated according to their Lindemann index (delta) using the criterion of delta> or =0.07. The lifetimes of the clusters at 230 K are longer than that at 250 K, and their ratios are the same as the ratio of structure relaxation times of bulk water at these temperatures. For both the filled and empty clusters, the lifetimes of 5(12)6(2) cagelike clusters are similar to that of 5(12) cagelike clusters. Although the methane molecules indeed make the filled cagelike water clusters live longer than the empty ones, the empty cagelike water clusters still have the chance of being long lived. These observations support the cluster nucleation hypothesis for the formation mechanisms of gas hydrates.
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http://dx.doi.org/10.1063/1.1763888 | DOI Listing |
Proteins
January 2025
Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Mumbai, India.
Vector-borne diseases pose a severe threat to human life, contributing significantly to global mortality. Understanding the structure-function relationship of the vector proteins is pivotal for effective insecticide development due to their involvement in drug resistance and disease transmission. This study reports the structural and dynamic features of D1-like dopamine receptors (DARs) in disease-causing mosquito species, such as Aedes aegypti, Culex quinquefasciatus, Anopheles gambiae, and Anopheles stephensi.
View Article and Find Full Text PDFChemistry
December 2024
School of Chemistry, University of Leeds, Woodhouse Lane, Leeds, LS2 9JT, UK.
Cage-catenanes are chemical constructs where two or more cage-like molecules or assemblies are mechanically interlocked together. We report a new class of cage-catenanes where dimeric metal-organic cage-catenanes are linked into larger assemblies through additional bridging metal chloride links. These crystalline materials are obtained from the reaction of tris(nicotinoyl)cyclotriguaiacylene (L1) with Cu(II) salts, and all feature a tetramer of cages where two {Cu(L1)(X)} cages (X=anion) are mechanically interlocked, and link to each other and to another {Cu(L1)(X)} cage-catenane through a planar, linear tetranuclear {Cu(μ-Cl)Cl} cluster.
View Article and Find Full Text PDFJ Chromatogr A
November 2024
Key Laboratory for Analytical Science of Food Safety and Biology, College of Chemistry, Fuzhou University, Fuzhou 350116, China; International (HongKong Macao and Taiwan) Joint Laboratory on food safety and environmental analysis, Fuzhou 350116, Fuzhou University, China. Electronic address:
The occurrence of microcystins (MCs) during harmful algal blooms (HABs) represents a major threat to freshwater environments. In this work, a novel surface amphiphilic hybrid porous polymers based on cage-like organosiloxanes (PCSs) was prepared for the enrichment of MCs. The copolymerization of bifunctional amphiphilic monomers, 2-methacryloyloxyethyl phosphorylcholine (MPC) and N-benzylquininium chloride (BQN), with the cross-linker methacryl substituted polyhedral oligomeric silsesquioxane (POSS) was achieved in an ionic liquid-based porogenic medium.
View Article and Find Full Text PDFJ Phys Chem Lett
October 2024
Dipartimento di Chimica "G. Ciamician", Università di Bologna, via F. Selmi 2, 40126, Bologna, Italy.
A 1:1 molecular complex of cysteamine with water is shown to adopt a cage-like structure where cysteamine accepts a relatively strong hydrogen bond from water while also engaging in two additional weaker interactions (SH···O and CH···O). Experimental and theoretical approaches confirm this conformer as the global minimum on the potential energy surface. Fitting of key structural parameters to experimentally determined moments of inertia yields consistent and accurate results for rotational and N nuclear quadrupole coupling constants which are shown to be challenging to calculate using methods.
View Article and Find Full Text PDFNanoscale
October 2024
Department of Chemistry and Chemical Engineering, Shandong University, Shanda South Road 27, 250100 Jinan, China.
An extended (, 19 distinct species) family of cage-like Cu-phenylsilsesquioxanes allowed us to accentuate the general regularities behind their structural organization. Influencing factors, namely the (i) size of external alkali metal ions (from Li to Cs) and (ii) nature of bridging linkers (including the smallest possible ones, like a water molecule) on the self-assembly/supramolecular assembly of such Cu-building blocks have been thoroughly explored. A CuK-based complex has been evaluated as a precatalyst in the oxidation of alkanes (cyclohexane, -heptane, methylcyclohexane) and alcohols.
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