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Incorporation of o-carborane into the backbone of poly­(dihexylfluorene)­s drastically affects emission properties due to an intramolecular charge-transfer state (ICT) that forms between the fluorene and carborane moieties in the polymer backbone, which is emissive and solvatochromic. Such polymers exhibit duel emissions from both the ICT state and the conjugated fluorene local excited state (LES). In order to evaluate the influence of higher degrees of LES conjugation on the emission properties of carborane-containing poly­(dihexylfluorene)­s, four random copolymers were synthesized with different feed ratios of 2,7-dibromo-9,9-dihexylfluorene and 1,2-bis­(7-bromo-9,9-dihexyl-9H-fluoren-2-yl)-closo-dicarbodecaborane. These polymerizations were carried out through Yamamoto coupling with greater equivalents of 2,7-dibromo-9,9-dihexylfluorene, and the photophysical properties were compared to the homopolymer of 1,2-bis­(7-bromo-9,9-dihexyl-9H-fluoren-2-yl)-closo-dicarbodecaborane. With increasing equivalents of 2,7-dibromo-9,9-dihexylfluorene the polymer molecular weight is increased from the homopolymer, the ground-state absorption is red shifted, and the emission spectra show gradually increasing LES character. Time-resolved spectroscopic methods displayed the characteristic ICT excited-state absorption and decay for three of the polymers, with the LES absorption and decay features increasing in intensity with increasing fluorene character in the polymer backbone. The polymer with the largest degree of conjugated fluorene shows excited-state properties consistent with a linear poly­(dihexylfluorene), showing negligible ICT character. In the solid state, the intensity of the ICT emission is enhanced as compared to the LES emission for the copolymers with the largest degree of conjugated fluorene. Through synthetic tuning, it is possible to produce polymers with higher molecular weights, and overall characteristics of the non-carborane-containing analogues, but maintain the useful properties of carborane-containing materials, like solvatochromism, in the solid state.

Self-report data suggests a large proportion of total physical activity (PA) occurs at work. However, adults with higher levels of occupational PA may compensate by engaging in less non-occupational PA. The study aims were to 1) estimate the intensity, volume, and duration of PA in American adults that occurs at work, and 2) determine if those more active at work are less active outside of work. A cross-sectional sample of full-time employed adults (N = 510) was recruited from Georgia city and county governments in 2013–2015. Participants wore an Actigraph GT3X + accelerometer for two weeks. In 2016, for 442 participants with complete data including work schedules and self-reported job titles, accelerometer wear minutes were classified as either occupational or non-occupational, and as sedentary, LPA (light-intensity PA), or MVPA (moderate-to-vigorous intensity PA). The proportion of daily PA that occurred during work was 41.2% for total PA, 41.0% for LPA, and 39.5% for MVPA. Higher levels of occupational LPA were associated with lower levels of non-occupational LPA (r = − 0.38, P < 0.0001). However, higher levels of occupational MVPA were associated with higher levels of non-occupational MVPA (r = 0.17, P < 0.0001). These associations remained significant in a MANOVA adjusting for labor sector and other covariates. On average, employed adults get more LPA and MVPA outside of work. Adults who do more occupational MVPA do not compensate by doing less non-occupational MVPA. In contrast, adults who do more occupational LPA do compensate by doing less non-occupational LPA. Evaluations of interventions to reduce sedentary behavior should be designed to detect compensation effects.