- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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Comprehensive Supramolecular Chemistry II || Polymers and Molecular Wires as Chemical Sensors
摘要： Sensors provide a critical interface between humans and the world around them. A sensor, according to the Oxford English dictionary, is “a device that detects or measures a physical property and records, indicates, or otherwise responds to it.” A sensor responds to an external stimulus and converts it into a signal that can be recorded. The human body has at least ?ve sets of sensors, i.e., nose, tongue, ears, eyes, and skin; and human beings sense the world by their smell, taste, hearing, sight, and touch. Examples of some commercially available sensors include temperature sensors, pressure sensors, ?ow sensors, stress/strain sensors, and conductivity sensors.
关键词： Polymers,Fluorescent Sensors,Molecular Wires,Chemical Sensors,Metallopolymers
更新于2025-09-11 14:15:04
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Designing Long-Range Charge Delocalization from First Principles
摘要： Efficient electronic communication over long distances is a desirable property of molecular wires. Charge delocalization in mixed-valence (MV) compounds where two redox centers are linked by a molecular bridge is a particularly well-controlled instance of such electronic communication, thus lending itself to comparisons between theory and experiment. We study how to achieve and control long-range charge delocalization in cationic organic MV systems by means of Kohn–Sham density functional theory (DFT), and show that a captodative substitution approach recently suggested for molecular conductance (T. Stuyver et al., J. Phys. Chem. C 122, 3194 (2018)) greatly enhances charge delocalization in para-phenylene-based wires. To ensure the adequacy of our DFT methods, we validate different protocols for organic MV systems of different lengths. The BLYP35 hybrid functional combined with a polarizable continuum model, established by Renz and Kaupp, is indeed capable of correctly describing experimentally observed length-dependent charge delocalization, in contrast to the long-range corrected functionals ω-B97X-D and ω-PBE. We also discuss the implications of these results for a first-principles description of the transition between coherent tunneling and incoherent hopping regimes in molecular conductance.
关键词： Charge Delocalization,Molecular Wires,Mixed-Valence Compounds,Quantum Electronic Structure,Density Functional Theory
更新于2025-09-09 09:28:46
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Electron Transport with Mobility, μ > 86 cm2/Vs, in a 74 nm Long Polyfluorene
摘要： The mobility of charges on conjugated polymers is a fundamentally important feature of these materials, but most fall far short of transport that might lead one to call them “molecular wires”. A commonly identified bottleneck is flexible dihedral angles between repeat units. Here we find a very high mobility, μ > 86 cm2/Vs, for electrons attached to polyfluorene polymers in isooctane, despite the presence of varied dihedral angles. The present data suggests that interactions with the surrounding medium may be a principal determinant of charge mobility.
关键词： mobility,molecular wires,conjugated polymers,polyfluorene,electron transport
更新于2025-09-04 15:30:14