The analysis of domain averaged Fermi holes (DAFH) was applied to the elucidation of the nature of the bonding interactions in supported metal carbonyls, where multicenter bonding of the bridging ligands and direct metal-metal bonds are considered as possible alternatives. The main focus is directed on the detailed scrutiny of the possible impact of the changes in the topology of electron density induced by the systematic variation of the geometry of the studied carbonyls on the picture of the bonding provided by the visual description in terms of DAFH analysis. It has been shown that irrespective of the dramatic changes in the topology of electron density exemplified by the existence and/or the lack of direct metal-metal bond path, the DAFH picture of the bonding remains practically unaffected and in all cases consistently suggests that the bonding of the bridging ligands exhibits the typical features of delocalized 3c-2e bonding.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1021/ic901197b | DOI Listing |
Polymers (Basel)
January 2025
Centre of Molecular and Macromolecular Studies, Polish Academy of Sciences, Sienkiewicza 112, 90-363 Lodz, Poland.
The deformation behavior and instabilities occurring during the drawing of high-density polyethylene (HDPE) were investigated using wide- and small-angle X-ray scattering (WAXS and SAXS) and scanning electron microscopy (SEM) in plain HDPE and paraffin wax- and/or chloroform-modified samples. In contrast to neat HDPE, the modified materials demonstrated strongly suppressed cavitation. However, regardless of cavitation, the tensile deformation of all samples was found to be governed by crystallographic mechanisms active in the crystalline lamellae, supported by shear in the amorphous layers, i.
View Article and Find Full Text PDFPolymers (Basel)
January 2025
School of Engineering, Institute for Materials and Processes, The University of Edinburgh, Sanderson Building, King's Buildings, Edinburgh EH9 3FB, UK.
The phase separation of high-density polyethylene (HDPE)-polypropylene (PP) blends was studied using atomic force microscopy in tapping mode to obtain height and phase images. The results are compared with those from scanning electron microscopy imaging and are connected to the thermomechanical properties of the blends, characterised through differential scanning calorimetry, dynamic mechanical analysis (DMA), and tensile testing. Pure PP, as well as 10:90 and 20:80 weight ratio HDPE-PP blends, showed a homogeneous morphology, but the 25:75 HDPE-PP blends exhibited a sub-micrometre droplet-matrix structure, and the 50:50 HDPE-PP blends displayed a more complex co-continuous nano/microphase-separated structure.
View Article and Find Full Text PDFMolecules
January 2025
Department of Chemistry, Middle Tennessee State University, 440 Friendship Street, Murfreesboro, TN 37132, USA.
Elevated dopamine (DA) levels in urine denote neuroblastoma, a pediatric cancer. Saccharide-derived carbon dots (CDs) were applied to assay DA detection in simulated urine (SU) while delineating the effects of graphene defect density on electrocatalytic activity. CDs were hydrothermally synthesized to vary graphene defect densities using sucrose, raffinose, and palatinose, depositing them onto glassy carbon electrodes (GCEs).
View Article and Find Full Text PDFMolecules
January 2025
Faculty of Chemistry, University of Wroclaw, 50-383 Wroclaw, Poland.
This research investigates the mechanism of the cyanide-type umpolung reaction in benzoin condensation using topological analysis of ELF and catastrophe theory. The study achieves a comprehensive understanding of the evolution of chemical bonds and non-bonding electron density in the reaction of benzaldehyde and cyanide ions. The results reveal that the reaction proceeds through five transition state structures, with the formation of Lapworth's cyanohydrin being the rate-determining step.
View Article and Find Full Text PDFMolecules
January 2025
College of Science, Liaoning Petrochemical University, Fushun 113001, China.
The electronic structure characteristics of bilayer graphyne, bilayer graphdiyne, and bilayer graphtriyne were systematically studied using molecular orbital (MO) analysis, density of states (DOS), and interaction region indicator (IRI) methods. The delocalization characteristics of the out-of-plane and in-plane π electrons (i.e.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!