Química Física, Universidad de Alcalá , E-28871 Alcalá de Henares, Madrid, Spain.
Published: February 2017
AI Article Synopsis
Article Abstract
Control of absorption spectra in chromophores is a fundamental aspect of many photochemical and photophysical processes as it constitutes the first step of the global photoinduced process. Here we explore the use of mechanical forces to modulate the light absorption process. Specifically, we develop a computational formalism for determining the type of mechanical forces permitting a global tuning of the absorption spectrum. This control extends to the excitation wavelength, absorption bands overlap, and oscillator strength. The determination of these optimal forces permits us to rationally guide the design of new mechano-responsive chromophores. Pyrene has been chosen as the case study for applying these computational tools because significant absorption spectra information is available for the chromophore as well as for different strained derivatives. Additionally, pyrene presents a large flexibility, which makes it a good system to test the inclusion of force probes as the strategy to exert forces on the system.
We investigate the comprehensive analysis's structural, electronic, optical, and elastic properties of Cs₂NaScX₆ (X = Cl, Br) double perovskites using density functional theory (DFT) implemented by the WIEN2k code. The results show that both compounds are in cubic phases. The calculated tolerance factors show both are stable compounds.
The fact that the photoabsorption spectrum of a material contains information about the atomic structure, commonly understood in terms of multiple scattering theory, is the basis of the popular extended X-ray absorption spectroscopy (EXAFS) technique. How much of the same structural information is present in other complementary spectroscopic signals is not obvious. Here we use a machine learning approach to demonstrate that within theoretical models that accurately predict the EXAFS signal, the extended near-edge region does indeed contain the EXAFS-accessible structural information.
Photosensitizing compounds are eco-friendly promising organic dyes for managing insect pests without facing the risk of resistance. The photodynamic efficacy of four Photosensitizing compounds (rose Bengal, rhodamine B, methylene blue and methyl violet) was monitored against the third larval instar of Spodoptera littoralis (Boisduval), after exposure to sunlight. The LC values of the four compounds; rose Bengal, rhodamine B, methylene blue and methyl violet recorded 0.
Centre for Nano and Material Sciences, Jain (Deemed-to-be) University, Jain Global Campus, Ramanagaram, Bangalore, 562112, Kanakpuram, Karnataka, India.
In this study, a series of new methoxy ester functionalized core fluorinated, chloro-fluorinated azobenzene derivatives were synthesized. The molecular structures of the azobenzene derivatives (3a-3c and 4a-4c) were confirmed through various analytical methods, with variations in the alkoxy chain length on one end of the aromatic ring. Optical absorption studies of 3a, 3b revealed π-π* transitions around 368-392 nm.
Anharmonic computations reveal an intense, narrow (20 cm, 0.043 μm) absorption feature at approximately 2160 cm (4.63 μm) in the vibrational spectra of 14 prototypical singly isocyano-substituted polycyclic aromatic hydrocarbons (NC-PAHs) attributed to the NC stretching mode.
