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Conjugated polymers are at the heart of numerous current and emerging technologies. Doping, a process by which charge carriers are introduced, is crucial to their functionality and performance. Despite significant historical context and the exploration of a broad chemical space, doping processes that are activated by formation of a ground-state charge-transfer complex (GS-CTC), which is mediated by the supramolecular hybridization between the frontier molecular orbitals of distinct molecular species, remain poorly understood. There are no clear demonstrations of this phenomena in contemporary donor–acceptor (DA) conjugated polymers (CP). Here, using diketopyrrolopyrrole-based donor–acceptor semiconducting polymers and a -conjugated penta-t-butylpentacyanopentabenzo[25]annulene “cyanostar” macrocycle, we demonstrate the first examples of features that control GS-CTC formation in contemporary DA CP frameworks. Using complementary experimental techniques and theory, we articulate how subtle molecular, electronic, and solid-state features impact supramolecular hybridization of the frontier molecular orbitals and impact the resultant (opto)electronic, magnetic, and transport properties. These studies demonstrate that subtle effects arising from the admixture between distinct -conjugated materials can have dramatic outcomes on properties and performance through modification of the density of states (DOS). These results will enable completely new design rules for organic semiconductors with precise property control. 

We report a novel synthetic route to a series of fused acene derivatives, in which linear extension of the fully conjugated core proves to be an efficient method to tune optoelectronic properties. 

The multiexciton quintet state,⁵TT, generated as a singlet fission intermediate in pairs of molecular chromophores, is a promising candidate as a qubit or qudit in future quantum information science schemes. 

Course-based undergraduate research experiences (CUREs) are high-impact practices that allow students to conduct research during class time. Benefits of a CURE can be maximized when integrated into a faculty member’s ongoing research. However, this can be particularly challenging for field biologists, especially when field sites are not situated near their university. Indeed, few existing CUREs are field based. One solution is to partner with a collaborator near the field site. We describe a semester-long CURE in an animal behavior class that involved collaboration among three institutions: researchers from two “distant” institutions have ongoing research at the “local” institution where the CURE took place. This model uses remote conferencing and strategic collaboration to meet all stakeholders’ needs. Undergraduate students engaged as active participants in collaborative inquiry-based work, learned in a cooperative context, and even participated in the publication process. The local principal investigator and their institution generated a high-impact course that integrated research and teaching. Likewise, the distant principal investigators were able to collect more extensive and longer-term field-based data than otherwise possible, and they gained valuable input from the local researchers that contributed to future projects. Remote collaborations open the door to international collaboration with smaller institutions, promoting greater inclusion in science. 

Abstract Animals eavesdrop on signals and cues generated by prey, predators, hosts, parasites, competing species, and conspecifics, and the conspicuousness of sexual signals makes them particularly susceptible. Yet, when sexual signals evolve, most attention is paid to impacts on intended receivers (potential mates) rather than fitness consequences for eavesdroppers. Using the rapidly evolving interaction between the Pacific field cricket,Teleogryllus oceanicus, and the parasitoid fly,Ormia ochracea, we asked how parasitoids initially respond to novel changes in host signals. We recently discovered a novel sexual signal, purring song, in Hawaiian populations ofT. oceanicusthat appears to have evolved because it protects the cricket from the parasitoid while still allowing males to attract female crickets for mating. In Hawaii, there are no known alternative hosts for the parasitoid, so we would expect flies to be under selection to detect and attend to the new purring song. We used complementary field and laboratory phonotaxis experiments to test fly responses to purring songs that varied in many dimensions, as well as to ancestral song. We found that flies strongly prefer ancestral song over purring songs in both the field and the lab, but we caught more flies to purring songs in the field than reported in previous work, indicating that flies may be exerting some selective pressure on the novel song. When played at realistic amplitudes, we found no preferences–flies responded equally to all purrs that varied in frequency, broadbandedness, and temporal measures. However, our lab experiment did reveal the first evidence of preference for purring song amplitude, as flies were more attracted to purrs played at amplitudes greater than naturally occurring purring songs. As purring becomes more common throughout Hawaii, flies that can use purring song to locate hosts should be favored by selection and increase in frequency.