Volume 68, Issue 4

The systematic experimental and bond-theoretical study of the phase width of the BaAl4 structure type in the ternary system BaIn4- BaHg4 shows that this structure type is stable up to BaIn1:7Hg2:3 (tetragonal, tI10, space group I4=mmm, a=474.2(3), c=1228.7(9) pm, R1=0.0529). The planar 44 layers (M(2) site) are preferentially formed by In, whereas Hg occupies the tips (M(1) site) of the [M(1)M(2)4] square pyramids. The layers of the pyramids are connected via short M(1)-M(1) dumbbells (bonds a). The analysis of the calculated band structures of BaIn2Hg2 in comparison to BaIn4 and RbIn4 shows that contributions of Ba-d states (which are missing for RbIn4) and Hg-d states (which are missing in the pure indides) are significant. The respective compound with the smaller triel gallium (Hg-richest phase: BaGa1:9Hg2:1, tetragonal, oI40, space group I41=amd, a=671.3(2), c=2220.4(8) pm, Z =8, R1=0.0641) forms a new superstructure of the BaAl4 structure with a partial ordering of three statistically occupied mixed Ga=Hg positions. The 44 nets are formed by an intermediate proportion of Ga=Hg. The tips of the pyramids are alternately formed by a Ga- and an Hg-rich position leading to smaller and larger bond lengths a’ and a”, respectively, between the tip atoms and, consequentely, a puckering of the 44 net. The two Hg-rich 3 : 11 compounds Ba3InHg10 and Ba3CdHg10 (orthorhombic, oI28, space group Immm, a=513.96(8)=511.50(2), b=993.8(2)=991.54(3), c=1500.7(3)=1499.26(5) pm, Z =2, R1=0.0619=0.0482) crystallize in the La3Al11 structure type, which is also observed for K3Hg11 and is closely related to the BaAl4 type: The square pyramidal nets are corrugated leading to a triplication of the BaAl4 unit cell along one of the tetragonal axes. In each third subcell the tips of adjacent pyramids are directly fused, this position being occupied exclusively by In and Cd. With the smaller triel gallium, the 3 : 11 compound Ba3Ga0:2Hg10:8 crystallizes in the Ba3ZnHg10 structure type (orthorhombic, oP28, space group Pmmn, a=709.36(4), b=1707.96(9), c=630.78(4) pm, Z =2, R1=0.0342). The structure contains folded layers of flat rectangular Ga=Hg pyramids, leaving large channels at the folds, in which Ba(1) and Hg(2) atoms alternate. The formation and stability ranges of 1 : 4, 3 : 11 and related 5 : 19 trieles/mercurides are discussed taking geometric, electronic and M13=Hg ,coloring‘ aspects into account. Graphical Abstract Barium-Triel-Mercuride BaM x Hg 4-x und Ba 3 M x Hg 11-x (M=Ga, In, Cd) / Barium Triel Mercurides BaM x Hg 4-x and Ba 3 M x Hg 11-x (M =Ga, In, Cd)

The potassium and rubidium thiosulfates (hydrates) considered in this work were originally obtained as by-products during several syntheses of mixed sulfido=oxido metallates. The interesting complexity of their structural chemistry has motivated us to investigate them in detail. The crystal structures of all title compounds have been determined using single-crystal X-ray data. The structure of the anhydrous potassium thiosulfate K 2 S 2 O 3 (monoclinic, space group P2 1/c , a=1010.15(14), b=910.65(12), c=1329.4(2) pm, b =111.984(11)º, Z =8, R1=0.0665) exhibits two crystallographically different thiosulfate anions, overall coordinated by 9=10 potassium cations. Their packing in the structure leads to a complex structure with a pseudo orthorhombic unit cell. The structure of the anhydrous salt is discussed in comparison with the known even more complicated 1=3 hydrate K 2 S 2 O 3 ·1/3 H 2 O (monoclinic, space group P2 1/c , a=938.27(6), b=602.83(4), c=3096.0(2) pm, b =98.415(6)º, Z =12, R1=0.0327). Under the chosen experimental conditions, rubidium forms the monohydrate Rb 2 S 2 O 3 ·H 2 O, which also crystallizes with a new, in this case less complex structure (monoclinic, space group C2/m, a=1061.4(1), b=567.92(4), c=1096.4(1) pm, b =97.40(1)º, Z =4, R1=0.0734). Its thiosulfate ions form double layers of equally oriented tetrahedral units. The bond lengths and angles of the thiosulfate ions in all title compounds and in the sodium salts used for comparison vary only very slightly (d S-S =199.8 - 203.0 pm, d S-O =144.8 - 147.4 pm), and the deviation from the ideal C 3v symmetry is very small, despite their complex packing. The overall coordination number of the thiosulfate ions by the alkali cations (and water molecules) increases systematically with the ionic radius of the counter cations and the amount of water molecules. For all known alkali thiosulfates, both the conventional and the calculated effective coordination numbers (ECoN) of the alkali cations as well as the partial molar volumes of the cations and the water molecules are compared and discussed. Graphical Abstract Kristallstrukturen der Alkalimetall-Thiosulfate A 2 S 2 O 3 nH 2 O (A/n = K/0, K/⅓ , Rb=1) / Crystal Structures of the Alkali Thiosulfates A 2 S 2 O 3 · nH 2 O (A/n = K/0, K/⅓ , Rb=1)

During attempts to synthesize a high-pressure phase of KSr 4 (BO 3 ) 3 using pressures of up to 12 GPa, single crystals of the normal-pressure phase KSr 4 (BO 3 ) 3 with sufficient quality for singlecrystal diffraction experiments could be obtained at 3 GPa and 1300 °C in a Walker-type multianvil apparatus. The single-crystal structure determination verified the published powder diffraction data of KSr 4 (BO 3 ) 3 revealing the non-centrosymmetric space group Ama2 with a = 1104:8(2), b=1199:1(2), c=688:8(2) pm and Z =4. Additionally, IR- and Raman-spectroscopic investigations were performed on single crystals of the compound. Graphical Abstract Single-crystal Structure Determination and Spectroscopic Characterization of KSr 4 (BO 3 ) 3

A new Lindqvist polyoxometalate-based hybrid compound with a helical chain structure, [Cu(bipy) 2 ][W 6 O 19 ] (1), (bipy = 2;20`-bipyridine), has been hydrothermally synthesized and characterized by elemental analysis, infrared spectroscopy, thermogravimetry, and single-crystal X-ray diffraction. The compound crystallizes in the space group C2/c of the monoclinic system. In 1, the [W 6 O 19 ] 2- anions are connected alternately with [Cu(bipy) 2 ] 2+ subunits to form a meso-helical chain. To our knowledge, this structure represents the first example of a helical chain structure consisting of the hexatungstate anion [W 6 O 19 ] 2- . The electrochemical properties of the title compound have been studied. Graphical Abstract Hydrothermal Synthesis and Crystal Structure of a Meso-Helical Chain Based on Lindqvist Polyoxometalates

A Mn(II) metal-organic framework {[MnL 2 (NCS) 2 ]·(H 2 O) 4 }n (1) with L=bis(pyridin-3-ylmethylene) biphenyl-2,20`-dicarbohydrazide has been synthesized and characterized by IR spectroscopy, elemental analysis, UV spectroscopy, thermogravimetric (TG) analysis, powder X-ray diffraction, and single-crystal X-ray structure determination. The Mn(II) atom has a distorted octahedral coordination environment with an N 6 donor set from four ligands and two NCS - anions. The structure of 1exhibits a layer framework containing tetranuclear metallacyclic ring units [Mn II 4 L 4 ] in the chair conformation. In addition, there are multiform O-H···O, C-H···O, N-H···O, and C-H···N hydrogen bonds and C-H···p interactions in a three-dimensional supramolecular network. Graphical Abstract Synthesis and Crystal Structure of a Mn(II) Metal-Organic Framework Based on a Polydentate Schiff Base Ligand

The ultrasound-assisted reaction of AgNO 3 , 2-amino-4,6-dimethylpyrimidine (dmapym) and 2,6-naphthalenedicarboxylic acid (H 2 npd) gave rise to a new 2D network of the formula [Ag 2 (dmapym) 2 (npd)]n (1). The atoms Ag1 and Ag2 in the complex show seesaw and distorted tetrahedral coordination geometries, respectively. The dmapym ligand acts as a bidentate bridge to bind paired Ag(I) ions into a chain. The chains are further connected by npd linkers to form the resultant 2D network reinforced by N-H···O hydrogen bonds between dmapym and npd. Weak C-H···p interactions are also found in the crystal structure. Complex 1 exhibits photoluminescence in the solid state at room temperature with an emission maximum at 418 nm upon excitation at 330 nm. Graphical Abstract Mixed Linker Strategy for the Construction of a Fluorescent 2D Network Based on [Ag 2 (COO) 2 ] as Secondary Building Unit

A series of tetrahydrobenzo[c]acridinone derivatives have been prepared by a one-pot fourcomponent reaction of 1-naphthol, aromatic aldehydes, dimedone, and ammonium acetate in aqueous media using a catalytic amount of titanium dioxide nanoparticles (TiO 2 NPs). The advantages of this novel protocol include the excellent yields, operational simplicity, short reaction time, easy work-up, reusability of the catalyst and an environmentally friendly procedure. Graphical Abstract TiO 2 Nanoparticles as an Efficient Catalyst for the One-pot Preparation of Tetrahydrobenzo[c]acridines in Aqueous Media

The Mizoroki-Heck coupling of 1-bromopyrene with acrylates provides a convenient access to a variety of 3-pyrenylacrylates in very good yields (up to 93%). Their photophysical properties combined with solvatochromic effects were studied. In addition, electrochemical oxidation potentials were determined by DPV (differential pulse voltammetry) measurements. The fine structure of the absorbance spectra obtained from photophysical measurements are compared with the results of theoretical calculations performed by time dependent TD-B3LYP methods using the 6-31G* basis set. Graphical Abstract 3-Pyrenylacrylates: Synthetic, Photophysical, Theoretical and Electrochemical Investigations

5-(2-Methoxyethyl)biphenyls have been prepared by regioselective formal [3+3] cyclocondensations of 1,3-bis(trimethylsilyloxy)-1,3-butadienes. Graphical Abstract Regioselective Synthesis of 5-(2-Methoxyethyl)biphenyls by Formal [3+3] Cyclocondensations of 1,3-Bis(trimethylsilyloxy)-1,3-butadienes

Thirteen 1-deoxynojirimycin (DNJ) derivatives of five different skeletal structures were designed and synthesized. The newly synthesized compounds were evaluated using an in vitro a- glucosidase assay, and kinetic parameters (Ki, IC50) were measured. Some DNJ derivatives showed weak a-glucosidase inhibitory activities, and the compounds 1-(3-benzyloxy-2-hydroxypropyl)- 2-hydroxymethyl-piperidine-3,4,5-triol (2a) and 1-{3-[1-(4-fluorophenyl)-1H-[1,2,3]triazol-4-ylmethoxy]- 2-hydroxypropyl}-2-hydroxymethyl-piperidine-3,4,5-triol (13d) showed activities comparable to that of DNJ. While 2a was found to be a reversible, non-competitive inhibitor of a-glucosidase with a Ki value of 1.56X10 -4 M and an IC50 value of 3.07X10x4 M, 13d was a reversible, competitive inhibitor of a-glucosidase with a Ki value of 2.08X10 -4 M and an IC50 value of 3.31X10 -4 M. Graphical Abstract Synthesis and Biological Activity of Novel Deoxynojirimycin Derivatives as Potent α-Glucosidase Inhibitors

Reaction of aromatic a-bromoketones, sodium azide and aromatic or aliphatic terminal acetylenes in the presence of Cu/Cu(OTf) 2 following the classical method (aqueous acetonitrile at room temperature) and under microwave irradiation (H 2 O at 85 °C) leads to 1,4-disubstituted 1,2,3-triazoles as the final products after simple filtration. Graphical Abstract Synthesis of 1,4-Disubstituted 1,2,3-Triazoles from Aromatic a-Bromoketones, Sodium Azide and Terminal Acetylenes via Cu/Cu(OTf) 2 -catalyzed Click Reaction under Microwave Irradiation

Temperature-dependent regioselectivity between amino and hydroxyl groups mediated by hydrogen bonding was observed in the reaction of acetic anhydride with 2-(2,3-dimethoxyphenyl)- 4-(2-hydroxyphenyl)-2,3-dihydro-1H-1,5-benzodiazepine (1), obtaining 1-acetyl-2-(2,3-dimethoxyphenyl)- 4-(2-hydroxyphenyl)-2,3-dihydro-1H-1,5-benzodiazepine (1a), when these were reacted at room temperature, and 4-(2-acetoxyphenyl)-1-acetyl-2-(2,3-dimethoxyphenyl)-2,3-dihydro-1H-1,5- benzodiazepine (1b), when they were refluxed (148 - 150 °C). Acylation of the less hindered analog 4-(2-hydroxyphenyl)-2-phenyl-2,3-dihydro-1H-1,5-benzodiazepine (2) via crotonyl chloride (a bulky acylating agent compared with acetic anhydride) afforded by refluxing only 1-crotonyl-4- (2-hydroxyphenyl)-2-phenyl-2,3-dihydro-1H-1,5-benzodiazepine (2a). All compounds were characterized spectroscopically, and the molecular structures of compounds 1a and 2a were determined by X-ray diffraction analysis. Graphical Abstract Synthesis of N-Acylated 1,5-Benzodiazepines: Differentiation between Two Possible Acylation Sites via Hydrogen Bonding

A chiral two-dimensional (2D) coordination polymer {[Zn(cmmb)(1,4-bbi)]·H 2 O}n (1) has been synthesized by a hydrothermal reaction of Zn(NO 3 ) 2 ·6H 2 O with 4- (carboxymethoxy)-2-methylbenzoic acid (H 2 cmmb) and 1,1`-(1,4-butanediyl)bis(imidazole) (1,4-bbi). It has been characterized by elemental analysis, X-ray crystallography, IR spectroscopy and thermogravimetry, and also by its fluorescence properties. The metal-organic layer of the complex is held together with its neighbors via C-H···O hydrogen bonds to give rise to a chiral three-dimensional supramolecular network. Graphical Abstract Synthesis, Crystal Structure and Properties of a Chiral 2D Zn(II) Coordination Polymer with Helical Chains