BODIPY-conjugated bis-terpyridine Ru(II) complexes showing ultra-long luminescence lifetimes and applications to triplet-triplet annihilation upconversion.

The poor excited-state properties of bis-terpyridine Ru(II) complexes have significantly limited the applications of these complexes as sensitizers in photocatalysis and triplet-triplet annihilation upconversion. In the present work, two novel ruthenium bis-terpyridine complexes (Ru-1 and Ru-2) conjugated with visible-light-harvesting bodipy chromophores were synthesized. These complexes showed strong absorption of visible light, the bodipy-localized intraligand triplet state (3IL) was efficiently populated, and the phosphorescence of bodipy at room temperature in both complexes was observed. The luminescence lifetimes of these complexes were significantly prolonged, with that of the heteroleptic complex Ru-2 prolonged to 37.9 µs and that of the homoleptic bis-terpyridine complex Ru-1 unprecedentedly prolonged to 356 µs, which was hundreds of times longer than the current longest emissive state achieved in ruthenium terpyridine complexes. The ultra-long triplet lifetimes and strong visible-light absorbing ability made them new candidates of triplet sensitizers, and were first applied to TTA-UC for terpyridine Ru(II) complexes with a Ru-1/Py system showing a ΦUC of 2.93% in dilute solutions at concentrations as low as 1.0 µM.

The time course of neural responses to social versus non-social unfairness in the ultimatum game.

The unfairness effects are always the hotspot within social psychology and cognitive neuroscience. However, people's neural responses to social versus non-social unfairness remain under-researched, especially about temporal features. We engaged participants in the Ultimatum Game to respond to human and computer proposers (representing social and non-social contexts respectively) and recorded their event-related potentials. The interactions elicited three components of interest: medial frontal negativity (MFN), late positive potential (LPP) and response related negativity (RRN). First, unfair human offers elicited larger MFN than unfair computer offers did, suggesting a greater perception of unfairness in the social context. Second, rejected unfair human offers elicited smaller LPP than rejected unfair computer offers did. This finding implies that the rejection to social unfairness could down-regulate the unfairness-aversive emotions. These two mechanisms explained the stronger resistance to social unfairness in behavioural results. Last, the RRN for unfairness rejections were larger than for fairness acceptances, but showed no variance to the two types of proposers, signifying a similar degree of response conflict behind rejections to social and non-social unfairness. These results of our exploratory study will be helpful in revealing the sociality effect on the perceptual, emotional and reappraisal processing during the unfairness response.

Neural Basis of Two Kinds of Social Influence: Obedience and Conformity.

Event-related potentials (ERPs) were used in this study to explore the neural mechanism of obedience and conformity on the model of online book purchasing. Participants were asked to decide as quickly as possible whether to buy a book based on limited information including its title, keywords and number of positive and negative reviews. Obedience was induced by forcing participants to buy books which received mostly negative reviews. In contrast, conformity was aroused by majority influence (caused by positive and negative comments). P3 and N2, two kinds of ERP components related to social cognitive process, were measured and recorded with electroencephalogram (EEG) test. The results show that compared with conformity decisions, obedience decisions induced greater cognitive conflicts. In ERP measurements, greater amplitudes of N2 component were observed in the context of obedience. However, consistency level did not make a difference on P3 peak latency for both conformity and obedience. This shows that classification process is implicit in both conformity and obedience decision-making. In addition, for both conformity and obedience decisions, augmented P3 was observed when the reviews consistency (either negative or positive) was higher.

Cognitive and emotional conflicts of counter-conformity choice in purchasing books online: an event-related potentials study.

Using event-related potentials (ERPs), this study investigated the neural substrates of the conflicts in counter-conformity choices in purchasing books online. For each trial, a participant decided whether to buy a book according to the title keyword, as well as the numbers of positive and negative reviews on the book. A participant's choice was termed conformity if she/he decided to buy the book under the condition of consistently positive reviews, or not to buy the book under the condition of consistently negative reviews, whereas the case was counter-conformity if a participant did the opposite. In the time window 300-600ms after the stimulus onset, a strong negative deflection of ERP (N500) was recorded when participants made counter-conformity choices. The topographic distribution of the N500 (N400-like) is not typical of the semantic N400. The N500 might be evoked by the cognitive and emotional conflicts faced by participants in counter-conformity choices. The present findings provide evidence that the N400 can be elicited by non-semantic conflicts.