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Polymers that release small molecules in response to mechanical force are promising for a wide variety of applications. While offering a general platform for mechanically triggered release, previous mechanophore designs based on masked 2-furylcarbinol derivatives are limited to polar protic solvent environments for efficient release of the chemical payload. Here, we report a masked furfuryl carbonate mechanophore incorporating a tethered primary alcohol that enables efficient release of a hydroxycoumarin cargo in the absence of a protic solvent. Density functional calculations also implicate an intramolecular hydrogen bonding interaction between the tethered alcohol and the carbonyl oxygen of the carbonate that reduces the activation barrier for carbonate fragmentation leading to molecular release. This new mechanophore design expands the generality of the masked 2-furylcarbinol platform for mechanically triggered release, enabling the implementation of this strategy in a wider range of chemical environments.

Teams are central to human accomplishment. Over the past half-century, psychologists have identified the Big-Five cross-culturally valid personality variables: Neuroticism, Extraversion, Openness, Conscientiousness, and Agreeableness. The first four have shown consistent relationships with team performance. Agreeableness (being harmonious, altruistic, humble, and cooperative), however, has demonstrated a non-significant and highly variable relationship with team performance. We resolve this inconsistency through computational modelling. An agent-based model (ABM) is used to predict the effects of personality traits on teamwork and a genetic algorithm is then used to explore the limits of the ABM in order to discover which traits correlate with best and worst performing teams for a problem with different levels of uncertainty (noise). New dependencies revealed by the exploration are corroborated by analyzing previously-unseen data from one the largest datasets on team performance to date comprising 3,698 individuals in 593 teams working on more than 5,000 group tasks with and without uncertainty, collected over a 10-year period. Our finding is that the dependency between team performance and Agreeableness is moderated by task uncertainty. Combining evolutionary computation with ABMs in this way provides a new methodology for the scientific investigation of teamwork, making new predictions, and improving our understanding of human behaviors. Our results confirm the potential usefulness of computer modelling for developing theory, as well as shedding light on the future of teams as work environments are becoming increasingly fluid and uncertain., Comment: Final version (open access) as published in journal

The field of polymer mechanochem. investigates the use of mech. force to promote selective chem. transformations. Polymer chains transduce external mech. forces to a particular covalent bond in mech. sensitive mols. called mechanophores, resulting in a specific chem. reaction. We report on a new mechanophore based on a cyclopentadienemaleimide Diels-Alder adduct that undergoes a retro-[4+2] cycloaddn. reaction promoted by mech. force to reveal a diarylethene (DAE) photoswitch. Initially, the mechanophore is photochem. inert because it does not possess the necessary 6p electronic framework required for electocyclization; however, ultrasound-induced mech. activation of the mechanophore covalently linked to polymer chains generates a DAE photoswitch, which isomerizes between colorless and colored forms upon exposure to UV and visible light. Control expts. confirm the mech. origin of the revealed photochromic activity and illustrate the thermal stability and reversible switching properties of the cyclopentadiene-based DAE photoswitch.

Mechanophores are mols. that undergo selective chem. transformations in response to applied mech. force. Covalent incorporation of mechanophores in polymers enables the coupling of mech. stress to covalent bond activation - an emerging field of research termed polymer mechanochem. We present new mol. design approaches for harnessing mech. force in polymers to promote useful chem. transformations. For example, targeted applications include the generation of photoactive compds. using mechanochem. to reveal locations of mech. stress in polymeric materials and release of small mols. using force.

Materials that change properties upon exposure to applied stimuli have received tremendous interest. Among various stimuli, light has unique advantages because it allows precise control over the location and timing. Moreover, irradn. parameters, such as light intensity and wavelength, can easily be modulated to comply with the system. Mol. design of polymers incorporating photocleavable groups enables photochem. control of covalent bonds or non-covalent intermol. interactions in polymer materials. We have developed three classes of new light-responsive polymer systems: 1) layer-by-layer polyelectrolyte films that switch interlayer charge-charge interactions from attractive to repulsive, 2) photopatternable conjugated polymers with photocleavable solubilizing sidechains that switches soly. in orthogonal solvents, and 3) polymer gels with phototunable viscoelastic properties and solubilities. Such novel photochem. approaches to control polymers have potential applications in three-dimensional photolithog. and photolabile drug delivery systems.

Leader humor has been considered one of the most promising yet least understood influential tools by psychologists and management scholars. Here, I review the growing body of research on leader humor and its implications for followers and organizations, showing that despite being theorized as a positive leadership tool, leader humor can function as a double-edged sword in bringing both beneficial and detrimental outcomes for followers and organizations.In the process, I identify six distinct mechanisms (three positive and three negative) through which leader humor affects followers. In a way, leader humor can be used to reduce or increase the social and psychological distance between leaders and followers. I also discuss the directions for future research on leader humor.

Using both experimental and field data, we examined how and what style of leader humor expression leads to positive work outcomes. We develop and test a dual process model (the affective mechanism and the cognitive mechanism) delineating the psychological process by which leader humor expressions influence follower outcomes. We test our model across two studies. Study 1 demonstrates in an experiment that the perceived funniness of leader humor causes followers to report greater positive affect as well as positive evaluation of the leader. Extending these findings into organizational field context, Study 2 surveys a sample of 211 employees and 47 managers and finds that employees’ positive affect at work and their positive evaluation of their manager mediated the relationship between perceived funniness of manager’s humor and employee performance. However, the mediation path of positive evaluation is negatively moderated by manager’s humor style such that when the manager has a self-deprecating humor style, the positive effect of perceived humor funniness will decrease. We also contribute to the leadership, affect and humor literature by suggesting the need to view leader humor expression as a perception by the recipient rather than intention of the sender, proposing two features of leader humor expression (perceived humor funniness and humor style) that have been neglected by past research.