Actual and Perceived Knowledge About COVID-19: The Role of Information Behavior in Media.

The COVID-19 pandemic poses a health threat that has dominated media coverage. However, not much is known about individual media use to acquire knowledge about COVID-19. To address this open research question, this study investigated how the perceived threat is linked to media use and how media use is associated with perceived and actual knowledge about COVID-19. In a German online survey conducted between April 16 and April 27, 2020, N = 952 participants provided information on their perceived threat and media use to inform themselves about COVID-19. In this process, they indicated how well they were informed about COVID-19 (perceived knowledge) and subsequently completed a COVID-19 knowledge test (actual knowledge). Results indicated that individuals who felt more threatened by COVID-19 used media more often to inform themselves (b = 0.20, p < 0.001) but focused on fewer different media channels (b = 0.01, p < 0.001). Further, frequent media use was associated with higher perceived knowledge (b = 0.47, p < 0.001), but not with higher actual knowledge about COVID-19 (b = -0.01, p = 0.938), reflecting an illusion of knowledge. Additionally, using fewer media channels was linked to higher perceived (b = 2.21, p < 0.001) and actual knowledge (b = 2.08, p = 0.008). Finally, explorative analyses on the use of different media channels revealed that an illusion of knowledge emerged for using social media, public television, and newspapers. Potential explanations for the findings and implications for future research are discussed.

Comparing the Ligand Behavior of N-Heterocyclic Phosphenium and Nitrosyl Units in Iron and Chromium Complexes.

N-Heterocyclic phosphenium (NHP) and nitrosonium (NO+) ligands are often viewed as isolobal analogues that share the capability to switch between different charge states and thus display redox "noninnocent" behavior. We report here on mixed complexes [(NHP)M(CO) n(NO)] (M = Fe, Cr; n = 2, 3), which permit evaluating the donor/acceptor properties of both types of ligands and their interplay in a single complex. The crystalline target compounds were obtained from reactions of N-heterocyclic phosphenium triflates with PPN[Fe(CO)3(NO)] or PPN[Cr(CO)4(NO)], respectively, and fully characterized (PPN = nitride-bistriphenylphosphonium cation). The structural and spectroscopic (IR, UV-vis) data support the presence of carbene-analogue NHP ligands with an overall positive charge state and π-acceptor character. Even if the structural features of the M-NO unit were in all but one product blurred by crystallographic CO/NO disorder, spectroscopic studies and the structural data of the remaining compound suggest that the NO units exhibit nitroxide (NO-) character. This assignment was validated by computational studies, which reveal also that the electronic structure of iron NHP/NO complexes is closely akin to that of the Hieber anion, [Fe(CO)3(NO)]-. The electrophilic character of the NHP units is further reflected in the chemical behavior of the mixed complexes. Cyclic voltammetry and IR-SEC studies revealed that complex [(NHP)Fe(CO)2(NO)] (4) undergoes chemically reversible one-electron reduction. Computational studies indicate that the NHP unit in the resulting product carries significant radical character, and the reduction may thus be classified as predominantly ligand-centered. Reaction of 4 with sodium azide proceeded likewise under nucleophilic attack at phosphorus and decomplexation, while super hydride and methyl lithium reacted with all chromium and iron complexes via transfer of a hydride or methyl anion to the NHP unit to afford anionic phosphine complexes. Some of these species were isolated after cation exchange or trapped with electrophiles (H+, SnPh3+) to afford neutral complexes representing the products of a formal hydrogenation or hydrostannylation of the original M═P double bond.

Tuning the overpotential of electrocatalytically active cyclopentadienylnickel complexes containing 1,4-diaza-1,3-butadienes (DAB) for proton reduction.

The complexes [CpNi(DAB)]BF4, Cp = cyclopentadienyl, DAB = substituted 1,4-diaza-1,3-butadienes, undergo two reduction processes. EPR spectroscopically active Ni(i) intermediates were observed despite the potential redox activity of the DAB ligands and these reduced species catalyse the conversion of electrons and protons (from acetic acid) into dihydrogen.