The bond length of a carbon-carbon sp2-sp2 sigma-bond without the perturbing effects of pi-interactions has been estimated by high level calculations on two prototypical systems: a 90 degrees -twisted form of butadiene and the tub conformer of cyclooctatetraene. The former system yields a value of 1.4818 A, considerably longer than previous estimates. The corresponding bond length in the latter is slightly shorter due to some pi-electron delocalization.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1021/jp7097334 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Exploring Moiré Superlattices and Memristive Switching in Non-van der Waals Twisted Bilayer BiOSe.
ACS Appl Mater Interfaces
January 2025
Department of Physics, Indian Institute of Technology Guwahati, Guwahati 781039, India.
The discovery of moiré physics in two-dimensional (2D) materials has opened new avenues for exploring unique physical and chemical properties induced by intralayer/interlayer interactions. This study reports the experimental observation of moiré patterns in 2D bismuth oxyselenide (BiOSe) nanosheets grown through one-pot chemical reaction methods and a sonication-assisted layer separations technique. Our findings demonstrate that these moiré patterns result from the angular stacking of the nanosheets at various twist angles, leading to the formation of moiré superlattices (MSLs) with distinct periodicities.
View Article and Find Full Text PDFAerodynamic analysis of complex flapping motions based on free-flight biological data.
Bioinspir Biomim
January 2025
Intelligent Robotics Institute, School of Mechatronical Engineering, Beijing Institute of Technology, Beijing 100081, People's Republic of China.
The wings of birds contain complex morphing mechanisms that enable them to perform remarkable aerial maneuvers. Wing morphing is often described using five wingbeat motion parameters: flapping, bending, folding, sweeping, and twisting. However, the specific impact of these motions on the aerodynamic performance of wings throughout the wingbeat cycle, and their potential to inform engineering applications, remains insufficiently explored.
View Article and Find Full Text PDFProgrammable Magnetic Hysteresis in Orthogonally-Twisted 2D CrSBr Magnets via Stacking Engineering.
Adv Mater
January 2025
Instituto de Ciencia Molecular (ICMol), Universitat de València, Catedrático José Beltrán 2, Paterna, 46980, Spain.
Twisting 2D van der Waals magnets allows the formation and control of different spin-textures, as skyrmions or magnetic domains. Beyond the rotation angle, different spin reversal processes can be engineered by increasing the number of magnetic layers forming the twisted van der Waals heterostructure. Here, pristine monolayers and bilayers of the A-type antiferromagnet CrSBr are considered as building blocks.
View Article and Find Full Text PDFClarifying the Cardiovascular Morphology and Associated Abnormalities in Patients with Double Inlet Right Ventricle Using Multidetector CT Angiography.
Pediatr Cardiol
January 2025
Department of Cardiovascular Radiology & Endovascular Interventions, All India Institute of Medical Sciences, New Delhi, 110029, India.
We sought to evaluate the intracardiac morphology and associated cardiovascular anomalies in patients with double inlet right ventricle (DIRV) on multidetector CT angiography. A retrospective search of our departmental database was conducted from January 2014 to January 2023 to identify patients with a diagnosis of DIRV on CT angiography. The intracardiac anatomy and associated cardiovascular abnormalities were systematically evaluated.
View Article and Find Full Text PDFStress-induced self-assembly of hierarchically twisted stripe arrays.
Sci Bull (Beijing)
December 2024
Department of Chemistry, Laboratory of Advance Materials, Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, State Key Laboratory of Molecular Engineering of Polymers, and iChEM, Fudan University, Shanghai 200433, China. Electronic address:
Hierarchical organization is prevalent in nature, yet the artificial construction of hierarchical materials featuring asymmetric structures remains a big challenge. Herein, we report a stress-induced self-assembly strategy for the synthesis of hierarchically twisted stripe arrays (HTSAs) with mesoporous structures. A soft and thin mesostructured film assembled by micelles and TiO oligomers is the prerequisite.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!