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Six homo-or heteroleptic tricationic Ir(R 1-tpy)(R 2-tpy) 3+ complexes (Ir1-Ir6, R 1 /R 2 = Ph, 4′-N(CH 3) 2 Ph, pyren-1-yl, or 4′-{2-[2-(2-methoxyethoxy)ethoxy]ethoxy}Ph, tpy = 2,2';6',2"terpyridine) were synthesized and tested for photodynamic therapy (PDT) effects. The ground-and excited-state characteristics of these complexes were studied systematically via spectroscopic methods and quantum chemistry calculations. All complexes possessed intraligand charge transfer (1 ILCT) / metal-to-ligand charge transfer (1 MLCT) dominated transition(s) in their low-energy absorption bands, which red-shifted with the increased electron-releasing strength of the R 1 /R 2 substituent. Five of the complexes exhibited ligand-centered 3 π,π*/ 3 ILCT/ 3 MLCT emission. With a stronger electron-releasing R 1 /R 2 substituent, the degree of charge transfer contribution increased, leading to a decrease of the emission quantum yield. When the 4′-N(CH 3) 2 Ph substituent was introduced on both tpy ligands, the emission of Ir3 was completely quenched. Our *

Mg2(Si,Sn)-based compounds have shown great promise for thermoelectric (TE) applications, as they are nontoxic and comprised abundantly available constituent elements. In this work, the crystal structures and TE properties of polycrystalline materials with nominal compositions Mg2Si0.35Sn0.65–x Bi x (x = 0, 0.015, 0.030, and 0.045) and Mg2Si y Sn0.97–y Bi0.03 (y = 0.30, 0.325, and 0.35) have been investigated. The electrical conductivity, Seebeck coefficient, and thermal conductivity are strongly affected by the presence of Bi. Undoped samples showed higher values of Seebeck coefficients (below 600 K), lower electrical conductivity, and lower thermal conductivity (above 600 K) in comparison to the Bi-doped samples. Furthermore, the signs of Seebeck coefficients are all negative, confirming that n-type conduction is dominant in these materials. Electrical conductivity was enhanced by increasing the Bi content up to 3% on the Si/Sn site because of the increasing amount of electron donors, and the absolute value of Seebeck coefficient decreased. When the Bi content is greater than 3%, lower zT values were obtained at 773 K. Thermal conductivity values might decrease with increasing Sn alloying for Mg2Si y Sn0.97–y Bi0.03, as mass and strain fluctuation caused by alloying can effectively scatter phonons. However, a different behavior was observed in higher Sn content material, possibly because of the absence of Mg atoms at the interstitial site [Mgi, on (1/2, 1/2, 1/2)] and vacancies of Mg atoms at the (1/4, 1/4, 1/4) site, as confirmed by Rietveld refinements. Outstanding figure of merit values in excess of unity were achieved with all samples, culminating in zT max = 1.35.

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In this paper, we propose a new discrete-continuous codification of the Chu–Beasley genetic algorithm to address the optimal placement and sizing problem of the distribution static compensators (D-STATCOM) in electrical distribution grids. The discrete part of the codification determines the nodes where D-STATCOM will be installed. The continuous part of the codification regulates their sizes. The objective function considered in this study is the minimization of the annual operative costs regarding energy losses and installation investments in D-STATCOM. This objective function is subject to the classical power balance constraints and devices’ capabilities. The proposed discrete-continuous version of the genetic algorithm solves the mixed-integer non-linear programming model that the classical power balance generates. Numerical validations in the 33 test feeder with radial and meshed configurations show that the proposed approach effectively minimizes the annual operating costs of the grid. In addition, the GAMS software compares the results of the proposed optimization method, which allows demonstrating its efficiency and robustness.

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Millimeter-sized single crystals of C60 were grown by sublimation of C60 powder in a vacuum for 6–24 h. The crystals had excellent facets, were free of C70 or solvent, and showed face-centered cubic symmetry with a very small mosaic spread down to 0.01°.