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Four new heteroleptic [Cu(NN)P2]+‐type cuprous complexes—1‐TPP, 2‐POP, 3‐Xantphos, and 4‐DPPF—were designed and synthesized using a diimine ligand 2‐(2′‐pyridyl)benzoxazole (2‐PBO) and different phosphine ligands (TPP, triphenylphosphine; POP, bis[2‐(diphenylphosphino)phenyl]ether; Xantphos, 4,5‐bis(diphenylphosphino)‐9,9‐dimethylxanthene; DPPF, 1,1′‐bis(diphenylphosphino)‐ferrocene). All complexes were characterized using single‐crystal X‐ray diffraction, spectroscopic analysis (infrared, UV–Vis.), elemental analysis, and photoluminescence (PL). Single‐crystal X‐ray diffraction revealed complexes 1–4 as isolated cation complex structures with a tetrahedral CuN2P2 coordination geometry and diverse P–Cu–P angles. Their UV–Vis. absorption spectra exhibited a blue‐shift sequence in wavelength with an enlarged P–Cu–P angle from 4 to 2 then to 3 and then to 1. The PL emission peaks of 1–3 also exhibited a similar blue‐shift sequence (2 → 3 → 1). Their PL lifetime in microseconds (~7.5, 5.1, and 4.7 μs for 1, 2, and 3, respectively) indicated that their PL behavior represents phosphorescence. Time‐dependent density functional theory (TD‐DFT) calculation and wavefunction analysis revealed that S1 and T1 states of 1–3 should be assigned as metal–ligand and ligand–ligand charge‐transfer (ML + L'L)CT states. Their UV–Vis. absorption and phosphorescence should be attributed to the charge transfer from the P–Cu–P segment to the 2‐PBO ligand. Therefore, as the P–Cu–P angle increased (lower HOMO), the energy of S1 and T1 states also increased, following the change of PL color. [ABSTRACT FROM AUTHOR]

Background: Previous studies revealed that vitamin K might help maintain muscle homeostasis, but this association has received little attention. We aimed to explore the associations of vitamin K intake with skeletal muscle mass and strength., Methods: We included cross-sectional data from the U.S. National Health and Nutrition Examination Survey (NHANES, 2011-2018). Vitamin K intake was assessed via 24-h recall. Covariate-adjusted multiple linear regression and restricted cubic splines were used to evaluate the associations of dietary vitamin K intake with skeletal muscle mass and strength, measured by dual-energy X-ray absorptiometry and handgrip dynamometer, respectively., Results: Dietary vitamin K intake was positively associated with skeletal muscle mass in males (β = 0.05747, p  = 0.0204) but not in females. We also revealed a positive association between dietary vitamin K intake and handgrip strength within the range of 0-59.871 μg/d ( P nonlinear  = 0.049). However, beyond this threshold, increasing vitamin K intake did not cause additional handgrip strength improvements., Conclusion: We provided evidence for a positive relationship between dietary vitamin K intake and skeletal muscle mass in males. Moreover, our study revealed a nonlinear relationship between dietary vitamin K intake and handgrip strength, highlighting an optimal intake range., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Wang, Chen, Guo, Wang, Bao, Zhang and Yu.)