Compete or rest? Willingness to compete hurt among adolescent elite athletes

Objective Training and competing despite underlying health problems is a common social practice in sport. Adolescent elite athletes are particularly vulnerable to possible health consequences of this risky behavior due to their very sensitive developmental stage. Conceptualizing this phenomenon of playing hurt as sickness presenteeism, and taking the concept of absence/presence legitimacy into account, this paper analyzes the propensity of adolescent elite athletes to compete in the face of health problems. The central aim is to empirically identify characteristics of elite sport subcultures which affect athletes’ willingness to compete hurt (WCH). Materials & methods Based on a comprehensive sample of 1138 German elite adolescent athletes from all Olympic sports (14–18 years), the paper applies classification tree analysis to analyze the social and individual determinants of the WCH. Results Determinants on three hierarchical levels were identified, including type of sport, perceptions of social pressure, coach's leadership style and athletes' age. The group with the highest WCH were athletes from technical sports who have a coach with an autocratic leadership style. Second was athletes from ball games, and those in aesthetic and weight-dependent sports, aged between 17 and 18 years old. The lowest mean WCH-score, by some distance, occurred amongst the group of endurance and power sports athletes who experienced no direct social pressure to play hurt. Conclusions The findings enhance our understanding of absence/presence legitimacy in highly competitive social contexts and contribute to the development of more effective target-group-specific health prevention programs for young athletes

Additional file 1: of Subjectively and objectively assessed social and physical environmental correlates of preschoolers’ accelerometer-based physical activity

Table S1. Sample characteristics of the subsample included in the final models and the subsample excluded from the final models due to incomplete data. (XLSX 35 kb

Square-Planar Cobalt(III) Pincer Complex

A series of square-planar cobalt­(II) complexes with pincer ligands {N­(CH₂CH₂P<i>t</i>Bu₂)₂}⁻ ({L₁^tBu}⁻), {N­(CH₂CH₂P<i>t</i>Bu₂)­(CHCHP<i>t</i>Bu₂)}⁻ ({L₂^tBu}⁻), and {N­(CHCHP<i>t</i>Bu₂)₂}⁻ ({L₃^tBu}⁻) was synthesized. Ligand dehydrogenation was accomplished with a new, high-yield protocol that employs the 2,4,6-tri<i>-tert</i>-butylphenoxy radical as hydrogen acceptor. [CoCl­{L_<i>n</i>^tBu}] (<i>n</i> = 1–3) were examined with respect to reduction, protonation, and oxidation, respectively. One-electron oxidations of [CoCl­(L₁^tBu)] and [CoCl­(L₂^tBu)] lead to ligand-centered radical reactivity, like amide disproportionation into cobalt­(II) amine and imine complexes. In contrast, oxidation of [CoCl­{L₃^tBu}] with Ag⁺ enabled the isolation of thermally stable, square-planar cobalt­(III) complex [CoCl­{L₃^tBu}]⁺, which adopts an intermediate-spin (<i>S</i> = 1) ground state with large magnetic anisotropy. Hence, pincer dehydrogenation gives access to a new platform for high-valent cobalt in square-planar geometry

Square-Planar Cobalt(III) Pincer Complex

A series of square-planar cobalt­(II) complexes with pincer ligands {N­(CH₂CH₂P<i>t</i>Bu₂)₂}⁻ ({L₁^tBu}⁻), {N­(CH₂CH₂P<i>t</i>Bu₂)­(CHCHP<i>t</i>Bu₂)}⁻ ({L₂^tBu}⁻), and {N­(CHCHP<i>t</i>Bu₂)₂}⁻ ({L₃^tBu}⁻) was synthesized. Ligand dehydrogenation was accomplished with a new, high-yield protocol that employs the 2,4,6-tri<i>-tert</i>-butylphenoxy radical as hydrogen acceptor. [CoCl­{L_<i>n</i>^tBu}] (<i>n</i> = 1–3) were examined with respect to reduction, protonation, and oxidation, respectively. One-electron oxidations of [CoCl­(L₁^tBu)] and [CoCl­(L₂^tBu)] lead to ligand-centered radical reactivity, like amide disproportionation into cobalt­(II) amine and imine complexes. In contrast, oxidation of [CoCl­{L₃^tBu}] with Ag⁺ enabled the isolation of thermally stable, square-planar cobalt­(III) complex [CoCl­{L₃^tBu}]⁺, which adopts an intermediate-spin (<i>S</i> = 1) ground state with large magnetic anisotropy. Hence, pincer dehydrogenation gives access to a new platform for high-valent cobalt in square-planar geometry

Square-Planar Cobalt(III) Pincer Complex

A series of square-planar cobalt­(II) complexes with pincer ligands {N­(CH₂CH₂P<i>t</i>Bu₂)₂}⁻ ({L₁^tBu}⁻), {N­(CH₂CH₂P<i>t</i>Bu₂)­(CHCHP<i>t</i>Bu₂)}⁻ ({L₂^tBu}⁻), and {N­(CHCHP<i>t</i>Bu₂)₂}⁻ ({L₃^tBu}⁻) was synthesized. Ligand dehydrogenation was accomplished with a new, high-yield protocol that employs the 2,4,6-tri<i>-tert</i>-butylphenoxy radical as hydrogen acceptor. [CoCl­{L_<i>n</i>^tBu}] (<i>n</i> = 1–3) were examined with respect to reduction, protonation, and oxidation, respectively. One-electron oxidations of [CoCl­(L₁^tBu)] and [CoCl­(L₂^tBu)] lead to ligand-centered radical reactivity, like amide disproportionation into cobalt­(II) amine and imine complexes. In contrast, oxidation of [CoCl­{L₃^tBu}] with Ag⁺ enabled the isolation of thermally stable, square-planar cobalt­(III) complex [CoCl­{L₃^tBu}]⁺, which adopts an intermediate-spin (<i>S</i> = 1) ground state with large magnetic anisotropy. Hence, pincer dehydrogenation gives access to a new platform for high-valent cobalt in square-planar geometry

Square-Planar Cobalt(III) Pincer Complex

A series of square-planar cobalt­(II) complexes with pincer ligands {N­(CH₂CH₂P<i>t</i>Bu₂)₂}⁻ ({L₁^tBu}⁻), {N­(CH₂CH₂P<i>t</i>Bu₂)­(CHCHP<i>t</i>Bu₂)}⁻ ({L₂^tBu}⁻), and {N­(CHCHP<i>t</i>Bu₂)₂}⁻ ({L₃^tBu}⁻) was synthesized. Ligand dehydrogenation was accomplished with a new, high-yield protocol that employs the 2,4,6-tri<i>-tert</i>-butylphenoxy radical as hydrogen acceptor. [CoCl­{L_<i>n</i>^tBu}] (<i>n</i> = 1–3) were examined with respect to reduction, protonation, and oxidation, respectively. One-electron oxidations of [CoCl­(L₁^tBu)] and [CoCl­(L₂^tBu)] lead to ligand-centered radical reactivity, like amide disproportionation into cobalt­(II) amine and imine complexes. In contrast, oxidation of [CoCl­{L₃^tBu}] with Ag⁺ enabled the isolation of thermally stable, square-planar cobalt­(III) complex [CoCl­{L₃^tBu}]⁺, which adopts an intermediate-spin (<i>S</i> = 1) ground state with large magnetic anisotropy. Hence, pincer dehydrogenation gives access to a new platform for high-valent cobalt in square-planar geometry

Four- and Five-Coordinate Osmium(IV) Nitrides and Imides: Circumventing the “Nitrido Wall”

Osmium nitride chemistry is dominated by osmium­(VI) in octahedral or square-pyramidal coordination. The stability of the d² configuration and preference of the strong σ- and π-donor nitride for apical coordination is in line with the Gray–Ballhausen bonding model. In contrast, low-valent osmium­(IV) or other d⁴ nitrides are rare and have only been reported with lower coordination numbers (CN ≤ 4), thereby avoiding π-bonding conflicts of the nitride ligand with the electron-rich metal center. We here report the synthesis of the square-planar osmium­(IV) nitride [Os^IVN­(PNP)] (PNP = N­(CHCHP<i>t</i>Bu₂)₂). From there, a square-pyramidal isonitrile adduct could be isolated, which surprisingly features basal nitride coordination. Analysis of this five-coordinate d⁴ nitride shows an unusual binding mode of the isonitrile ligand, which explains the preference of the weakest σ-donor and strongest π-acceptor isonitrile for apical coordination

A Ruthenium Hydrido Dinitrogen Core Conserved across Multielectron/Multiproton Changes to the Pincer Ligand Backbone

A series of ruthenium­(II) hydrido dinitrogen complexes supported by pincer ligands in different formal oxidation states have been prepared and characterized. Treating a ruthenium dichloride complex supported by the pincer ligand bis­(di-<i>tert</i>-butylphosphinoethyl)­amine (H-PNP) with reductant or base generates new five-coordinate <i>cis</i>-hydridodinitrogen ruthenium complexes each containing different forms of the pincer ligand. Further ligand transformations provide access to the first isostructural set of complexes featuring all six different forms of the pincer ligand. The conserved <i>cis</i>-hydridodinitrogen structure facilitates characterization of the π-donor, π-acceptor, and/or σ-donor properties of the ligands and assessment of the impact of ligand-centered multielectron/multiproton changes on N₂ activation. Crystallographic studies, infrared spectroscopy, and ¹⁵N NMR spectroscopy indicate that N₂ remains weakly activated in all cases, providing insight into the donor properties of the different pincer ligand states. Ramifications on applications of (pincer)Ru species in catalysis are considered

Dinitrogen Splitting and Functionalization in the Coordination Sphere of Rhenium

[ReCl₃(PPh₃)₂(NCMe)] reacts with pincer ligand HN­(CH₂CH₂P<i>t</i>Bu₂)₂ (<i>H</i>PNP) to five coordinate rhenium­(III) complex [ReCl₂(PNP)]. This compound cleaves N₂ upon reduction to give rhenium­(V) nitride [Re­(N)­Cl­(PNP)], as the first example in the coordination sphere of Re. Functionalization of the nitride ligand derived from N₂ is demonstrated by selective C–N bond formation with MeOTf

Stabilizing Doubly Deprotonated Diazomethane: Isolable Complexes with CN₂^2– and CN₂^– Radical Ligands

Transition metal complexes with a doubly deprotonated diazomethane (CNN2–) ligand have been proposed as fleeting intermediates in nitrogen transfer reactions. However, in contrast to isoelectronic azide (N3–), well-defined examples are unknown. We here report the synthesis and characterization of isolable complexes with terminal and bridging CNN2– ligands, stabilized by platinum­(II) pincer fragments. Bonding within the allenic dimetallanitrilimine core (Pt–NNC–Pt) was probed by oxidation of the bridging ligand. Enhanced reactivity toward [3 + 2]-cycloaddition with CO2 was obtained. Photofragmentation favors N–NC over NN–C bond cleavage as a route to cyanide and a transient metallonitrene complex