SYNTHESIS AND STRUCTURAL CHARACTERIZATION OF A NEW tetrakis-(CARBOXYLATO-O,O’) BRIDGED DICOPPER COMPLEX WITH TRIPHENYLPHOSPHINOPROPIONATE

A novel binuclear copper (Ⅱ) complex,namely [Cu 2｛Ph 3P(CH 2) 2CO 2｝ 4(NO 3) 2]·(NO 3) 2 1,has been synthesized from the reaction of Cu(NO 3) 2·4H 2O with Ph 3P +(CH 2) 2CO - 2 L.The single crystal X ray structural analysis of 1 indicates that the compound crystallizes in space group P1(No.2) with a=12.652(3),b=18.983(4),c=9.102(3),α=97.26(2)°,β=107.38(2)°,γ=102.22(2)° and Z=1.In complex 1,a pair of Cu(Ⅱ) atoms are bridged by carboxylate groups of four ligand molecules with a Cu…Cu distance of 2.738 to form a tetrakis (carboxylato O,O) bridge dimetal core,and the apical coordination positions are occupied by monodentate nitrato anions,which is rare in the structures of similar Cu(Ⅱ) complexes in which the apical ligands are usually neutral molecules.The result shows that introducing the anionic ligands into the coordination sphere of the Cu(Ⅱ) atom significantly increases the Cu…Cu distance.

Boosting lithium storage of Li-B alloys through regulating lithium content

Li-B alloy is expected to meet the expanding demands of energy storage,primarily driven by their high energydensity and structural stability.The fibrous porous skeleton can increase the electrochemical active area and reduce thelocal current density,therefore diminishing the lithium dendrites.In this study,we prepared Li-B alloys with differentlithium contents and examined the impact of lithium content on the structure and electrochemical properties of Li-Balloys.With the increase of lithium content,the spacing between the skeleton of the Li-B alloys increases.The lithiumdeposition on the top of the skeleton decreases,leading to thinner SEI,and lower polarization.The Li-B alloy with thehighest lithium content(64 wt.%lithium content)in the symmetric battery exhibits the longest cycle time,lasting over140 h at 1 mA/cm^(2)and 0.5 mA·h/cm^(2),with a minimal overpotential of 0.08 V.When paired with LiNi_(0.5)Co_(0.2)Mn_(0.3)O_(2),thefull battery has the highest specific discharge capacity and the best rate capacity.

Synthesis, characterization, and theoretical analysis of three new nonlinear optical materials K7MRE2B15O30（M= Ca and Ba, RE= La and Bi）

Three new complex borate compounds K7CaBi2B15O30, K7CaLa2B15 O30 and K7BaBi2B15O30 have been synthesized by the high-temperature solution method.K7CaLa2B15O30and K7CaBi2B15O30crystallize in the chiral trigonal space group R32, while K7BaBi2B15O30 crystallizes in the noncentrosymmetric orthorhombic polar space group Pca21. All of the title compounds have similar three-dimensional crystal structures, which are composed of isolated B5 O10 groups and LaO6 or BiO6 octahedra, and K^+, Ca^2+, and Ba^2+ cations fill into the cavities to keep charge balance. Based on our research, in the system of K7 MIIRE2 B15O30(MII= Ca, Sr,Ba, Zn, Cd, Pb, K/RE0.5;RE = Sc, Y, La, Gd, Lu, Bi),K7BaBi2B15O30 is unique and crystallizes in a different space group, which enriches the structural chemistry of borate.Detailed structural analyses indicate that the structural variation is due to the difference in size and coordination number of the alkaline-earth metal cations. Besides, UV-Vis-NIR spectroscopy analysis and the second-harmonic generation(SHG) measurement on the powder samples show that K7CaBi2B15O30 exhibits a UV cutoff edge(about 282 nm) and a moderate SHG response(about 0.6 × KDP). In addition,thermal analysis and infrared spectroscopy were also presented. To better understand the structure-property relationships of the title compounds, the first-principles calculations have been performed.