Volume 68, Issue 7

The lanthanoid(III) oxide fluoride sulfides M 6 O 2 F 8 S 3 (M = La-Nd, Sm, Gd) can be obtained by reacting the rare-earth metals, their trifluorides and sesquioxides with elemental sulfur in appropriate molar ratios at 850 °C flux-assisted by NaCl in gas-tightly sealed niobium or tantalum ampoules. All compounds are colorless, except for those containing M = Pr with green, M = Nd with lilac and M = Sm with yellow color. They form transparent single crystals as needles or rods. The M 6 O 2 F 8 S 3 representatives crystallize in a hexagonal structure (space group: P6 3 /m; a≈1382 - 1326, c≈398 - 376 pm, c/a≈0:288 - 0.284; Z =2) with two different crystallographic M 3+ positions. The (M2) 3+ cations reside in ninefold coordination of anions arranged as tricapped trigonal prisms formed by three F - , four mixed-occupied O 2- /F - and two S 2- anions, resembling the unique M 3+ coordination sphere of the M 3 OF 5 S-type oxide fluoride sulfides. The (M1) 3+ cations are surrounded by square antiprisms built of four O 2- /F - and S 2- anions each, which are capped by one F - anion each, again resulting in a ninefold coordination similar to that of the A-MFS-type fluoride sulfides. While the crystallographically unique S 2- anions have six cationic neighbors arranged in trigonal prisms, there are four different light-anion positions. Two of them, representing only fluoride anions, are situated in a triangular environment of cations ((F1) - : planar, (F2) - : non-planar). The mixed-occupied light-anion positions (F3) - =(O3) 2- and (F4) - =(O4) 2- exhibit tetrahedral coordination spheres with a ratio F - :O 2- =2 : 1. The M 6 O 2 F 8 S 3 arrangement is characterized by an empty hexagonal channel structure created by (F1) - anions with a potential of accommodating alkali-metal cations like Na + . All single-crystal X-ray structure investigations did not indicate any ordering of the O 2- and F - anions, but MAPLE calculations revealed a slightly favored oxygen occupation for the (F4) - =(O4) 2- rather than for the (F3) - =(O3) 2- position. Electron-beam microanalyses gave no evidence for the incorporation of either Na + or Cl - ions stemming from NaCl used as the flux. Graphical Abstract Oxidfluoridsulfide der Lanthanoide vom Formeltyp M 6 O 2 F 8 S 3 (M=La–Nd, Sm, Gd) / Oxide Fluoride Sulfides of the Lanthanoids with the Formula M 6 O 2 F 8 S 3 (M = La–Nd, Sm, Gd)

In the course of the synthesis of mixed oxidosulfido molybdates and tungstates by passing H 2 S gas through solutions of the oxido metalates, several new salts containing the metalates [MOS 3 ] 2- besides further anions (halides X - , hydrosulfide SH - or thiosulfate S 2 O 2- 3 ) were obtained as well-formed crystals. Their crystal structures have been determined using single crystal X-ray data. The salts containing SH - as the additional anion crystallize with a new structure type (orthorhombic, space group Pmn2 1 , M=Mo=W, T M =20=-125 °C: a=957.7(2)/954.15(2), b=636.2(2)/636.19(1), c=812.4(2)/809.88(2) pm, Z =2, R1=0.0319=0.0185). The mixed sulfidomolybdate/ chloride K 3 [MoO 1.25 S 2.75 ]Cl (orthorhombic, space group Pca2 1 , a=1246.3(1), b=623.20(4), c=1230.44(8) pm, Z =4, R1=0.0472) is isotypic with the sulfidotungstate K 3 [WOS 3 ]Cl, but contains 25% of the disulfido molybdate. The structures of the SH - and the Cl - salts are closely related: In both cases, the trisulfido metalates are overall coordinated by cuboctahedra of 12 K + ions, and the small additional anions are centered in K + octahedra. In this regard, the structures are both derivatives of the cubic perovskite (and thus the Cu 3 Au) type. This crystallographic group-subgroup relation is discussed in detail. Yellow hexagonal columns of the double salt K 6 [WOS 3 ] 2 (S 2 O 3 ) were obtained by the methanothermal decomposition of the disulfidotungstate K 2 [WO 2 S 2 ]. It crystallizes with a new structure type (hexagonal, space group P6 3 mc, a=983.78(8), c=1227.3(1) pm, Z =2, R1=0.0175). Like in the other mixed salts, the two crystallographically different [WOS 3 ] 2- anions exhibit an overall cuboctahedral coordination by 12 potassium cations. The smaller S 2 O 2- 3 anions are surrounded by nine K + ions arranged in the form of two flat facesharing octahedra. Again similar to the mixed halides and hydrosulfides, the two K polyhedra around the anions, here present in a 2 : 1 ratio, are arranged in a space-filling packing, in this case related to the ht- BaMnO 3 (and thus the Ni 3 Ti) structure type. According to their ‘double salt’ character, the Mo/W-O and Mo/W-S distances and the intramolecular vibrational frequencies of the tetrahedral moieties of the title compounds are similar between them and those in the pure potassium trisulfido metalates. This further becomes apparent from the additive nature of their molar volumes, which correspond to the sum of the volumes of the simple salts KCl, KSH or K 2 (S 2 O 3 ) and K 2 [MoOS 3 ]. Graphical Abstract Kalium-Doppelsalze mit den gemischten Trisulfidometallat-Ionen [MoOS 3 ] 2- und [WOS 3 ] 2- / Potassium Double Salts with the Mixed Trisulfidometalate Ions [MoOS 3 ] 2- and [WOS 3 ] 2-

Three Keggin-based metal-organic frameworks (MOFs) containing multi-nuclear silver subunits, [Ag 7 (ptz) 5 (H 2 O) 2 ][H 2 SiMo 12 O 40 ] (1), [Ag 8 (ptz) 5 (H 2 O) 2 ][AsW 12 O 40 ] (2) and [Ag 7 (ptz) 5 (H 2 O)][HAsMo 12 O 40 ] (3) (ptzH=5-(4-pyridyl)-tetrazole), have been synthesized under hydrothermal conditions by changing the inorganic polyanions. The new compounds have been characterized by elemental analyses, TG analyses, IR spectroscopy, and single-crystal X-ray diffraction. In compound 1, the multi-nuclear Ag 5 (ptz) 5 subunits are interconnected to form chains, which are further linked by Ag I cations to construct a 3D MOF with large channels. Pairs of SiMo 12 O 4 0 4- polyanions reside in the channels as penta-dentate inorganic ligands. In 2, six Ag I cations link five ptz- anions to construct a hexa-nuclear subunit [Ag 6 (ptz) 5 ] + , which is interconnected to form chains. These chains are further linked by Ag I cations to construct a 3D MOF, where AsW 12 O 4 0 3- polyanions reside as hexa-dentate ligands. Compound 3exhibits a 3D MOF based on Ag 5 (ptz) 5 subunits, in which the hexa-dentate AsMo 12 O 40 3- polyanions are incorporated. The rigid tetrazole-based ligand ptz - plays an important role in the formation of the multi-nuclear subunits of the title compounds. The electrochemical properties of compound 1and the photocatalytic properties of compounds 1and 3have been investigated. Graphical Abstract Three 3D Metal-Organic Frameworks Constructed from Keggin Polyanions and Multi-nuclear Ag I Clusters: Assembly, Structures and Properties

kgd The hydrothermal reactions of 5-(benzimidazol-1-ylmethyl)isophthalic acid (H 2 L) with Zn(II) and Cd(II) salts lead to the formation of the two new complexes [Cd(L)] (1) and [Zn(L)] (2). In the presence of 2-(pyridin-2-yl)-1H-benzimidazole (pybim) as auxiliary ligand, complex [Zn(L)(pybim)] (3) was obtained. Complexes 1-3have been characterized by single-crystal and powder X-ray diffraction, IR spectroscopy, and elemental and thermogravimetric analyses. Complexes 1and 2are isostructural and exhibit a binodal (3,6)-connected 2D network structure with (4 3 ) 2 (4 6 .6 6 .8 3 ) topology; 3 consists of uninodal 3-connected 2D (6 3 ) hcb networks. The influential factors of synthetic strategies on the coordination modes of the ligands and on the structures and properties of the resulting complexes are discussed. The luminescence properties of 1-3were investigated. Graphical Abstract Zn(II) and Cd(II) Coordination Polymers with an N,O-Donor Ligand: Structural Characterization and Fluorescence Properties

L Three new metal-organic frameworks based on Zn 2+ and 1,4-diazoniabicyclo[2.2.2]octane-1,4- diacetate () were synthesized and fully characterized by single-crystal X-ray diffraction and other methods. The linker L provides both positively charged quaternary ammonium centers and a flexible methylene chain, which brings conformational diversity to the system. The same reactants, and the same preparation procedures were used for the syntheses of Zn L Cl 2 (1), Zn L 2 (NO 3 )(OH)·(DMF)·(H 2 O) (2) and Zn L 3 (NO 3 ) 2 (H 2 O) (3), to study the role of solvents and anions during the synthesis. All three MOFs show one-dimensional networks with different topologies. Closed loops with different ring sizes could be found in 2and 3along the chain. Rings with 22 atoms were found in 2, while the smallest loop in 3contains 44 atoms, including four linkers and four zinc atoms. Clearly, the solvent, stoichiometries of the reactants, and the anions had an impact on the formation of the three distinct network structures. Graphical Abstract Loop-containing One-dimensional Metal-Organic Frameworks from Flexible Betaine Linkers and Zinc Salts by Controlled Synthesis

The reactions of the lithio-o-carborane Li 2 C 2 B 10 H 10 with ClCH 2 CH 2 CH 2 Br were studied under various conditions. While the main product is the known exo-polyhedrally cyclized 1,2- (1,3-propanediyl)-o-carborane (2), the expected 3-chloropropyl-substituted carborane products 1- (ClCH 2 CH 2 CH 2 )C 2 B 10 H 11 (3) and 1,2-(ClCH 2 CH 2 CH 2 ) 2 C 2 B 10 H 10 (4) can be obtained in a total yield of 22%. In the presence of CuCl, the same reaction proceeded rather slowly and gave compound 3and bis(o-carborane) (5) in small yields, with the recovery of the starting o-C 2 B 10 H 12 . Compounds 2- 4were characterized by means of IR and NMR spectroscopy and mass spectrometry, as well as by single-crystal X-ray diffraction. Graphical Abstract Synthesis and Characterization of 3-Chloropropyl-substituted o- Carboranes: Crystal Structures of 1,2-(1,3-Propanediyl)-o-carborane, 1-(3-Chloropropyl)-o-carborane and 1,2-Bis(3-chloropropyl)-ocarborane

Photocatalytic ring opening of α-epoxyketones by 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) in acetone resulted in the diastereoselective formation of 1,3-dioxolanes through C α -O bond cleavage. The facility of the ring opening is influenced by the nature and the location of the additional substituent on the a-epoxyketones. Graphical Abstract Diastereoselective 1,3-Dioxolane Formation by Photocatalytic Ring Opening of α-Epoxyketones

A one-pot and efficient approach to the synthesis of dialkyl 2-[1-[(alkoxycarbonyl)anilino]-2(1H)- (isoquinolin-2-yl) (or -quinolin-1-yl or -pyridin-1-yl)]-2-butenedioates is described. This method involves a three-component reaction between isoquinoline, quinoline or pyridine, dialkyl acetylenedicarboxylates and N-phenylcarbamates under solvent-free conditions, without using any catalyst and at room temperature. The mild reaction conditions and good yields of the products exhibit the synthetic advantage of this method. Graphical Abstract Solvent-free Synthesis of 1,2-Disubstituted Derivatives of 1,2- Dihydroisoquinoline, 1,2-Dihydroquinoline and 1,2-Dihydropyridine

The cyclocondensation of 4-methylthiosemicarbazide with 2-bromo-1,2-diphenylethan-1-one in ethanol afforded isomeric 2-methylamino-5,6-diphenyl-6H-3,4-thiadiazine and 2-hydrazono-3- methyl-4,5-diphenyl-2,3-dihydro-1,3-thiazole. A pyrazole was obtained by cyclocondensation and subsequent desulfurization of the thiadiazine when the reaction was carried out in concentrated hydrochloric acid. A chemical proof of the structures has been provided. The product distribution of the cyclizations strongly depends on the substitution pattern of the starting materials, and the cyclizations of methylthiosemicarbazide with 2-bromo-1,2-diphenylethan-1-one behaved considerably different from that of the analogous reactions of α-bromoacetophenone. Graphical Abstract Cyclocondensations of Substituted Thiosemicarbazides with 2-Bromo- 1,2-diphenylethan-1-one

Homophthalates were prepared by formal [3+3] cyclocondensation of 1,3-bis(silyl enol ethers) with silylated methyl 3,5-dioxohexanoate. Graphical Abstract Synthesis of Homophthalates by [3+3] Cyclocondensation Reactions of 1,3-Bis(silyloxy)-1,3-butadienes with Silylated Methyl 3,5-Dioxohexanoate

A new approach to γ-alkylidenetetronic acids is reported which is based on Me 3 SiOTf-catalyzed [3+2] cyclization of 4-tert-butoxy-1,3-bis(trimethylsilyloxy)-1,3-butadiene with oxalyl chloride, orthogonal protection of the α-hydroxy group by benzylation and subsequent deprotection of the β-hydroxy group. Graphical Abstract 4-tert-Butoxy-1-ethoxy-1,3-bis(trimethylsilyloxy)-1,3-butadiene. A New Diene and its Application to the Synthesis of γ-Alkylidenetetronic Acids

We have calculated the vibrational spectra of isoamyl alcohol and of tert-amyl alcohol using Density Functional Theory (DFT) with the Becke-3 Lee Yang Parr (B3LYP) functional and a 6-311+G** atomic basis set. The energies of the conformers were also calculated with ab initio Perturbation Theory of second (MP2) and fourth order restricted to single, double and quadruple excitations (MP4 SDQ) with the same basis set. We found rather complicated equilibria of four conformations in each case, counting only those with appreciable abundancies. PED data were compared with GAUSSVIEW animations. The calculated wavenumbers agree rather well with the experimental ones when the gauche-trans conformer is assumed as the most important one for isoamyl alcohol, and the gauchegauche one for tert-amyl alcohol. However, some of the experimental bands had to be assigned also to other conformers, indicating their presence in the equilibrium mixture. Due to sterical reasons both the CO and the OH bonds appear to be weaker in the tertiary alcohol, considering the wavenumbers of the CO and OH bond stretching vibrations. The bond lengths point into the same direction, however, the OH bond in the tertiary alcohol is only slightly longer than that in the primary alcohol. Graphical Abstract Equilibrium Structures and Vibrational Assignments for Isoamyl Alcohol and tert-Amyl Alcohol: A Density Functional Study