The electrostatic attraction between the separated charges in long-range excited charge-transfer states originates from the non-local Hartree-Fock exchange potential and is, thus, a non-local property. Present-day time-dependent density functional theory employing local exchange-correlation functionals does not capture this effect and therefore fails to describe charge-transfer excited states correctly. A hybrid method that is qualitatively correct is described.

The absorption spectra of neutral pentacene (C 22 H 14 ) and its radical cation (C 22 H 14 + ) and anion (C 22 H 14 -) isolated in solid Ne, Ar, and Kr have been measured from the ultraviolet to the near-infrared. The associated vibronic band systems and their spectroscopic assignments are discussed together with the physical and chemical conditions governing molecular anion production in matrices doped with alkali metal (Na or K). TD-DFT calculations were carried out to assist in the assignments for the measured spectral features of the pentacene ions.

This study examines college environments and outcomes among students in three different types of living-learning programs compared with a control sample at one university. Results reveal that living-learning students exhibit higher levels of engagement in college activities with stronger academic outcomes, and experiences that varied by program type.

The need to discover and develop new antimalarial therapeutics is severe. The annual mortality attributed to malaria, currently approximately 2.5 million, is increasing due primarily to widespread resistance to currently used drugs. One strategy to identify new treatment alternatives for malaria is to examine libraries of diverse compounds for the possible identification of novel scaffolds. Beginning with libraries of drug or drug-like compounds is an ideal starting point because, in the case of approved drugs, substantial pharmacokinetic and toxicologic data should be available for each compound series. We have employed a high throughput screen of the MicroSource Spectrum and Killer collections, a library of known drugs, bioactive compounds, and natural products. Our screening assay identifies compounds that inhibit growth of Plasmodium falciparum cultured in human erythrocytes. We have identified 36 novel inhibitors of P. falciparum, of which 19 are therapeutics, and five of these drugs exhibit effective 50% inhibitory concentrations within similar ranges to therapeutic serum concentrations for their currently indicated uses: propafenone, thioridazine, chlorprothixene, perhexiline and azlocillin. The findings we report here indicate that this is an effective strategy to identify novel scaffolds and therefore aid in antimalarial drug discovery efforts.

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We investigate the assignment of electronic transitions in alkyl peroxy radicals. Past experimental work has shown that the phenyl peroxy radical exhibits a transition in the visible region; however, previous high level calculations have not reproduced this observed absorption. We use time dependent density functional theory (TDDFT) to characterize the electronic excitations of the phenyl peroxy radical as well as other hydrocarbon substituted peroxy radicals. TDDFT calculations of the phenyl peroxy radical support an excitation in the visible spectrum. Further, we investigate the nature of this visible absorption using electron attachment/detachment density diagrams of the peroxy radicals and present a qualitative picture of the origin of the visible absorption based on molecular orbital perturbations. The peroxy radical substituent is also compared against isoelectronic radical groups. The visible absorption is determined to be dependent on mixing of the alkyl and radical substituent orbitals.

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