Volume 235, Issue 10

Polycrystalline Sc 5 Cu 2 In 4 was synthesized by induction melting of the elements and small single crystals were obtained by a slow cooling sequence. Sc 5 Cu 2 In 4 is the first coinage metal representative in the family of the so-called 5-2-4 intermetallics. The Zr 5 Ir 2 In 4 type structure of Sc 5 Cu 2 In 4 was refined from single crystal X-ray diffractometer data: Pnma , a  = 1716.75(6), b  = 677.94(12), c  = 760.69(2) pm, wR 2 = 0.0531, 1932 F 2 values and 58 variables. Sc 5 Cu 2 In 4 adopts a superstructure of the Lu 5 Ni 2 In 4 type (doubling of the b axis and klassengleiche symmetry reduction from Pbam to Pnma ), caused by dislocation of the copper atoms (puckering effect). Geometrically, Sc 5 Cu 2 In 4 is a 4:1 intergrowth structure of distorted AlB 2 and CsCl related slabs.

The yttrium-rich intermetallic compounds Y 14 Ni 3 Cd 3 and Y 6 Co 2 Zn were obtained by direct reactions of the elements in sealed tantalum tubes in an induction furnace. Both samples were characterized by X-ray powder diffraction and the structures were refined from single-crystal X-ray diffraction data: Lu 14 Co 3 In 3 type, P 4 2 / nmc , a  = 960.06(5), c  = 2314.9(1) pm, wR 2 = 0.0669, 2034 F 2 values, 63 parameters for Y 14 Ni 3.16(2) Cd 2.84(2) and Ho 6 Co 2 Ga type, Immm , a  = 943.08(7), b  = 950.08(7), c  = 997.64(7) pm, wR 2 = 0.0476, 981 F 2 values, 34 parameters for Y 6 Co 2 Zn. One cadmium site shows a small degree of Cd/Ni mixing, leading to the composition Y 14 Ni 3.16(2) Cd 2.84(2) . Although both compounds crystallize with significantly different structure types, they show very similar monomeric building units: (i) transition metal centered trigonal prisms of yttrium, (ii) empty Y 6 octahedra and (iii) icosahedral coordination of the cadmium respectively zinc atoms. The condensation patterns of these building units are discussed and for Y 14 Ni 3.16(2) Cd 2.84(2) , we elaborate a crystal chemical building principle along with the rare earth metal-rich phases RE 15 Rh 5 Cd 2 (La 15 Rh 5 Cd 2 type), RE 23 T 7 X 4 (Pr 23 Ir 7 Mg 4 type), RE 4 TX (Gd 4 RhMg type) and RE 10 TX 3 / RE 9 TX 4 (ordered Co 2 Al 5 versions). The structures of Y 14 Ni 3 Cd 3 and Y 6 Co 2 Zn show dumbbell formation: 306 pm Cd–Cd in Y 14 Ni 3 Cd 3 and 224 pm Co1–Co1 and 246 pm Co2–Co2 in Y 6 Co 2 Zn.

We have investigated the crystal structure of the synthetic analogue of the mineral iwateite using powder diffraction and Raman spectroscopy. Na 2 BaMn(PO 4 ) 2 crystallizes in the space group P 3‾$‾{3}$ m 1 (No. 164) with cell parameters a  = 5.37292(1) Å, and c  = 7.09538(1) Å ( R wp  = 5.7%, V  = 177.38 Å 3 , Z  = 1). The space group assignment is supported by the experimentally observed 11 Raman active modes which agree with the expected number of modes for the P 3‾$‾{3}$ m 1 symmetry.

Synthesis, crystal structures and IR spectra of the first representatives of calcium hydrogen selenite halides are reported. Colourless prismatic crystals of calcium hydrogen selenite chloride Ca(HSeO 3 )Cl and corresponding hydrated analogue Ca(HSeO 3 )Cl(H 2 O) were produced upon evaporation of aqueous solutions. Ca(HSeO 3 )Cl is monoclinic, P 2 1 / c , a  = 7.0031(11) Å, b  = 7.7336(12) Å, c  = 8.5024(13) Å, β = 109.889(3)°, V  = 433.02(12) Å 3 , R 1  = 0.039. Ca(HSeO 3 )Cl(H 2 O) is orthorhombic, Pbca , a  = 6.222(4) Å, b  = 10.413(7) Å, c  = 16.875(10) Å, V  = 1093.3 (12) Å 3 , R 1  = 0.041. Ca(HSeO 3 )Cl and Ca(HSeO 3 )Cl(H 2 O) represent new structure types. In both structures, Ca 2+ cations adopt mixed-ligand environments formed by oxygen atoms of hydrogen selenite anions (and water molecules for Ca(HSeO 3 )Cl(H 2 O)) and chloride ions. Both structures are layered. The crystal structure of Ca(HSeO 3 )Cl(H 2 O) demonstrates a rare phenomenon of hydrogen-bonded assembly of water and chloride in the interlayer space.

The crystallographic parameters of the incommensurately ordered phase ηʺ of the composition Cu 1.235 Sn are reported. This phase belongs to the group of ordered Ni 2 In/NiAs-type phases, with a NiAs-type arrangement Cu(1)Sn and additional Cu(2) atoms partially occupying trigonal-bipyramidal interstices in an ordered fashion, leading to the formula Cu(1)Cu(2) 0.235 Sn = Cu 1.235 Sn. The structure model, afterward refined on the basis of powder X-ray diffraction data, has been derived on the basis of the slightly Cu-poorer commensurately ordered η′-Cu 6 Sn 5 (=Cu 1.2 Sn) phase but also on previously reported commensurate structure models η 8 -Cu 1.25 Sn and η 4+1 -Cu 1.243 Sn derived from selected area electron diffraction data. In line with a recent work (Leineweber, Wieser & Hügel, Scr. Mater. 2020, 183 , 66–70), the incommensurate ηʺ phase is regarded as a metastable phase formed upon partitionless ordering of the η high-temperature phase with absent long-range ordering of the Cu(2) atoms. The previously described η 8 and η 4+1 superstructure are actually of the same phase, and the corresponding superstructure models can be regarded as approximant structures of the ηʺ phase. The refined structure model is described in 3+1 dimensional superspace group symmetry C 2/ c ( q 1 0 -q 3 )00 with a unit cell of the average structure with lattice parameters of a av = 4.21866(3) Å, b av = 7.31425(5) Å, c av = 5.11137(3) Å and b av = 90.2205(5)° and a unit cell volume V = 157.717(2) Å 3 . The modulation vector is with q 1 = 0.76390(4), q 3 = 1.51135(5), and governs the spatial modulation of the occupancy of the Cu(2) atoms described by a Crenel function. The occupational ordering is accompanied by displacive modulations of the atoms constituting the crystal structure, ensuring reasonable interatomic distances on a local level. In particular, the spatial requirements of pairs of edge-sharing Cu(2)Sn 5 trigonal bipyramids (Cu(2) 2 Sn 8 ) lead to a measurable splitting of some fundamental reflections in the powder diffraction data. This splitting is considerable smaller in η′-Cu 1.20 Sn, which lacks such pairs due to the lower Cu content.

The title compound [Cu 4 (NH 3 ) 12 -(µ 2 -CN) 8 -Pd 4 (CN) 8 ] was prepared from the aqueous solution Cu 2+ –  N,N,N′,N′ -tetraethylethane-1,2-diamine – [Pd(CN) 4 ] 2− , where the addition of excess amounts of ammonia caused the dissolution of the precipitate formed during reaction. Using this method, we prepared and structurally characterized the new complex of Cu(II) containing ammine ligand with tetracyanidopalladate(II) anion incorporated within the molecule. The crystal structure of compound is molecular; the unit cell contains centrosymmetric octanuclear molecules in which all central atoms lies on mirror plane. Generally, the structure of the molecule can be divided into central cyclic part and terminal pendants. The structure contains nitrogen atoms derived from the ammonia molecules coordinated to Copper(II) atoms. They are involved in the formation of N-H···N hydrogen bonds type.

Seven biguanide derivatives were prepared by the nucleophilic reaction between dicyandiamide and p -substitute aniline derivatives or memantine or adamantine under acidic conditions. The cyclization of the biguanide compounds were also conducted via acetone to give 1,3,5-triazine derivatives. The structures of the synthesized compounds were characterized by analytical methods. The solid state structures of [HL 5 ]Cl, [H 2 L 7 ]Cl 2 , [HL 1a ]Cl and [HL 5a ]Cl were investigated by X-ray diffraction study. The acetylcholinesterase and α-glucosidase inhibitor properties of the compounds were then evaluated by the spectroscopic method. The compounds were found to show considerable acetylcholinesterase and α-glucosidase inhibitory activities compared to the approved drugs. The cyclization of biguanide derivatives with acetone did not affect inhibition of acetylcholinesterase, yet increased the α-glucosidase inhibition.

A synthesis of the trans -dibromogold(III) t -Bu-Xantphos complex and its self-assembly into infinite 1-dimensional chain in the solid state is reported. The new complex characterized using elemental analyses (C, H, N), ESI-MS, 1 H and 13 C NMR techniques and X-ray diffraction analysis. Results of DFT calculations followed by the topological analysis of the electron density distribution within the framework of QTAIM method at the ωB97XD/DZP-DKH level of theory reveal that strength of attractive intermolecular non-covalent interactions Br···Br in the crystal is 1.2–1.6 kcal/mol.