The Franck-Condon envelopes calculated for the two lowest states are almost completely contained within the envelope of the lowest PES band. A comparison of the predicted PES of CHT and NCD showed much closer agreement of the PES with that of CHT. An analysis of the 1H and 13C nuclear magnetic resonance (NMR) spectra of CHT showed no evidence of NCD. The increased chemical shifts arising from the higher frequencies used here lead to significant changes in appearance when compared with earlier NMR spectra.For the prototypical two-dimensional hybrid organic-inorganic perovskites (2D HOIPs) (AE4T)PbX4 (X = Cl, Br, and I), we demonstrate that the Frenkel-Holstein Hamiltonian (FHH) can be applied to describe the absorption spectrum arising from the organic component. We first model the spectra using only the four nearest neighbor couplings between translationally inequivalent molecules in the organic herringbone lattice as fitting parameters in the FHH. We next use linear-response time-dependent density functional theory (LR-TDDFT) to calculate molecular transition densities, from which extended excitonic couplings are evaluated based on the atomic positions within the 2D HOIPs. We find that both approaches reproduce the experimentally observed spectra, including changes in their shape and peak positions. The spectral changes are correlated with a decrease in excitonic coupling from X = Cl to X = I. Importantly, the LR-TDDFT-based approach with extended excitonic couplings not only gives better agreement with the experimental absorption line shape than the approach using a restricted set of fitted parameters but also allows us to relate the changes in excitonic coupling to the underlying geometry. We accordingly find that the decrease in excitonic coupling from X = Cl to Br to I is due to an increase in molecular separation, which in turn can be related to the increasing Pb-X bond length from Cl to I. Our research opens up a potential pathway to predicting optoelectronic properties of new 2D HOIPs from ab initio calculations and to gain insight into structural relations from 2D HOIP absorption spectra.The remarkable success of x-ray free-electron lasers and their ability to image biological macromolecules while outrunning secondary radiation damage due to photoelectrons, by using femtosecond pulses, raise the question of whether this can be done using pulsed high-energy electron beams. In this paper, we use excited state molecular dynamics simulations, with tabulated potentials, for rare gas solids to investigate the effect of radiation damage due to inelastic scattering (by plasmons, excitons, and heat) on the pair distribution function. We use electron energy loss spectra to characterize the electronic excitations responsible for radiation damage.A Ce atom reaction with propene is carried out in a pulsed laser vaporization molecule beam source. Several Ce-hydrocarbon species formed by the C-H and C-C bond activation of propene are observed by time-of-flight mass spectrometry, and Ce(C3Hn) (n = 4 and 6) are characterized by mass-analyzed threshold ionization (MATI) spectroscopy and density functional theory, multiconfiguration, and relativistic quantum chemical calculations. The MATI spectrum of each species consists of two vibronic band systems, each with several vibronic bands. Ce(C3H6) is identified as an inserted species with Ce inserting into an allylic C-H bond of propene and Ce(C3H4) as a metallocycle through 1,2-vinylic dehydrogenation. Both species have a Cs structure with the Ce 4f16s1 ground valence electron configuration in the neutral molecule and the Ce 4f1 configuration in the singly charged ion. The two vibronic band systems observed for each species are attributed to the ionization of two pairs of the lowest spin-orbit coupled states with each pair being nearly degenerate.Toxicants like Pb in lead-based perovskite solar cells (PSCs) may become available to humans through leaching and transport through water, air, and soil. Here, we summarize the potential toxicity of different substances in PSCs and determine the leaching concentration of typical heavy metals used in PSCs through dynamic leaching tests (DLTs). Extraction fluids for the standard toxicity characteristic leaching procedure, synthetic precipitation leaching procedure, and deionized water were used as the DLT leaching solutions. Results indicated that the leaching concentration of Pb exceeded the hazardous waste limit of 5 mg/L. In addition, Pb was found to continuously leach out in the leaching cycles of water extraction. The findings confirmed that discarded PSCs may release Pb when subjected to water, rain, and landfill leachate. Total organic carbon and chemical oxygen demand analyses indicated that discarded PSCs could increase the oxygen consumption and may release CO2 into the environment.Transannular C-H heteroarylation of amines provides rapid access to complex scaffolds that are otherwise difficult to synthesize. Wide adaptation of this emerging reaction for medicinal chemistry requires a broad understanding of substrate scope and more robust experimental conditions. In this article, we report a new ligand to promote the transannular reaction of a range of fused- and bridged-bicyclic secondary amines with a broad set of heteroarenes. The method was also successfully applied to the arylation of one spiro-bicyclic amine, a class of substrates that has not been studied in the context of transannular C-H activation reactions. The broad application of this transannular C-H heteroarylation methodology is currently hampered by the difficulty of removing the directing group. The development of a new directing group that is easier to remove will expand the utility of this reaction.Huperserratines A (1) and B (2), two Lycopodium alkaloids with an unprecedented 5-aza-bicyclo[10.4.0]hexadecane skeleton and an oxime function, were isolated from Huperzia serrata. Their structures including absolute configurations were determined by extensive NMR spectroscopic and X-ray diffraction analysis.  https://www.selleckchem.com/products/sbc-115076.html  Compounds 1 and 2 were the first examples of macrocyclic Lycopodium alkaloids with an aza-12-membered ring. A plausible biogenetic pathway of these compounds was also proposed. Compound 1 exhibited moderate anti-HIV-1 activity with an EC50 of 52.91 μg/mL and a therapy index greater than 3.78.