Single crystals of Li(6)CuB(4)O(10) have been synthesized, and its crystal structure has been determined. Li(6)CuB(4)O(10) crystallizes in the non-centrosymmetric triclinic space group P1 (No. 1). The structure consists of isolated [CuB(4)O(10)](6)(-) polyanions that are bridged by six LiO(4) tetrahedra. Li(6)CuB(4)O(10) is a congruently melting compound. It produces SHG intensity similar to that produced by KH(2)PO(4) and is phase-matchable.

This paper reports the evaluation of the cubic B site cation-ordered double perovskite system Ba2Co2−x (Mo1/2Nb1/2) x O6, resulting in the single phase composition Ba2CoMo0.5Nb0.5O6−δ (BCMN) with a mixed Co charge state stabilized by a combination of Mo and Nb doping as a new mixed conductor with potential SOFC cathode applications. X-ray, neutron, and electron diffraction show that hexagonal intergrowths found in multiple phase samples at lower Mo/Nb contents are suppressed in BCMN, which has large domains of rock-salt ordered B site cations with separate Co and Mo/Nb sites. Conductivity measurement and impedance spectroscopy investigation shows that BCMN has a considerably reduced dc conductivity compared with materials such as BSCF but exhibits comparable electrochemical properties to some existing cathode materials in symmetrical cell measurements, and shows higher structural stability and reduced reactivity with the Ce0.8Sm0.2O2−δ (SDC) electrolyte. The role of Mo in dioxygen activation is proposed to offset the reduction that the d 0 Mo(VI) and Nb(V) cations on the B site produce in the electronic and ionic conductivity.

Nutraceutical compound p-coumaric acid, a phytochemical that possesses antioxidant and anti-inflammatory properties, was cocrystallized with nicotinamide, a member of the vitamin B complex, resulting in the discovery of three polymorphic 1:1 cocrystals. Slurries of two forms of the 1:1 cocrystal in water induced conversion to a 2:1 (p-coumaric acid-nicotinamide) cocrystal. In situ monitoring of this conversion at limited conditions by dispersive Raman spectroscopy illustrates rapid incomplete transformation. Additionally, a variety of conditions were evaluated to reach complete conversion. All four cocrystals were characterized by X-ray powder diffraction, thermal analyses, and spectroscopic techniques. In addition, single crystal structures for two of the 1:1 polymorphic cocrystals are presented. Further, competitive slurries, isothermal solution calorimetry, and differential scanning calorimetry analyses at a variety of heating rates were employed to explore the thermodynamic relationships among the three polymorphs.

A second polymorph of an anhydrous 1:1 caffeine citric acid cocrystal (C 8 H 10 N 4 O 2 , C 6 H 8 O 7 ) is reported. Crystals were analyzed using single crystal X-ray diffraction and the structure was solved in the monoclinic space group P2 1 /c with unit cell parameters a = 13.7783(8) Å , b = 12.3149(8) Å , c = 9.6587(6) Å , and b = 92.854(4)°. The three dimensional hydrogen bonding network is compared to the two dimensional network of the previously reported polymorph. Graphical Abstract A second polymorph of an anhydrous 1:1 caffeine citric acid cocrystal (C 8 H 10 N 4 O 2 , C 6 H 8 O 7 ) is reported, and the three dimensional hydrogen bonding network is compared to the two dimensional network of the previously reported polymorph.

Crystal frameworks that can accommodate a wide range of elements, oxidation states, and stoichiometries are an important component of solid-state chemistry. These frameworks allow for unique comparisons of different metal-cation compositions with identical atomic arrangements. The mineral Lyonsite, alpha-Cu(3)Fe(4)(VO(4))(6), is emerging as the archetypal framework structure for a large class of materials, similar to known frameworks such as perovskite, garnet, apatite, and spinel. The new lyonsite-type oxides Li(2.82)Hf(0.795)Mo(3)O(12) and Li(3.35)Ta(0.53)Mo(3)O(12), in which hafnium and tantalum retain their highest oxidation states, are presented to advance the concept of the lyonsite structure as an adaptable framework.