Volume 64, Issue 8

A range of new 7-phenyl-2H,5H-pyrano[4,3-b]pyran-5-ones and related tricyclic heterocycles was prepared in a single step by means of a domino Knoevenagel condensation/6π-electron electrocyclization under different reaction conditions, including thermal and microwave conditions. The influence of several ionic liquids as solvents was also studied Graphical Abstract Synthesis of Phenylsubstituted 2H,5H-Pyrano[ 4,3-b] pyran-5-ones and Related Heterocycles via a Domino Knoevenagel Condensation/ 6π-Electron Electrocyclization of 4-Hydroxy-6-phenyl-2H-pyran-2-one with Cyclic and Acyclic α, β-Unsaturated Aldehydes under Different Conditions Synthesis and Crystal Structure of the High-pressure Iron Borate β-FeB2O4 Synthesis and Crystal Structure of the High-pressure Iron Borate β-FeB2O4 Synthesis and Crystal Structure of the High-pressure Iron Borate β-FeB2O4 Synthesis and Crystal Structure of the High-pressure Iron Borate β-FeB2O4 Synthesis and Crystal Structure of the High-pressure Iron Borate β-FeB2O4

The iron borate β -FeB 2 O 4 was synthesized under high-pressure / high-temperature conditions of 8 GPa and 1030 ◦ C. The structure of β -FeB 2 O 4 is isotypic to HP-NiB 2 O 4 , representing the second example of a borate in which every BO 4 tetrahedron shares a common edge with a second one. β - FeB 2 O 4 crystallizes in the space group C2/c (Z = 4) with the parameters a = 950.0(2), b = 562.9(2), c = 443.7(1) pm, β = 108.50(3) ◦ , V = 0.22495(8) nm 3 , R1 = 0.0293, and wR2 = 0.0647 (all data). The structure consists of layers of BO 4 tetrahedra, connected via strings of edge-sharing FeO 6 octahedra. A ligand field splitting of Δ o ≈8860 cm −1 is estimated from polarized single-crystal electronic absorption spectra of β -FeB 2 O 4 . The tetragonal distortion of the ligand field in the [Fe II O 6 ] chromophore amounts to −(8/3)dσ ≈2900 cm −1 . In the range of 16000 cm −1 ≤ṽ ≤24000 cm −1 , rather strong spin-forbidden transitions within the [Fe II O 6 ] chromophore are observed Graphical Abstract Synthesis and Crystal Structure of the High-pressure Iron Borate β-FeB 2 O 4

Ruby-red single crystals of Ag 13 I 4 (AsO 4 ) 3 were prepared for the first time by reacting a stoichiometric mixture of Ag 2 O, AgI and As 2 O 3 at elevated oxygen pressure of 120 MPa and at a temperature of 350 ◦ C. The polyhedral crystals belong to the monoclinic space group P2 1 /m with a = 9.247(1), b = 7.152(1), c = 17.674(2) Å , β = 91.492(2) ◦ , and Z = 2. The structure is fully ordered and was solved by Direct Methods, and refined on single crystal diffraction data (10376 observed reflections, R1 = 3.28 %). The crystal structure is built up of two two-dimensional interlocked partial structures, one consisting of silver and iodine ions, the other of silver and arsenate(V) ions. The slabs extend in the ac plane, and the Ag-I framework is linked to the AsO 4 3 − units by Ag-O contacts. The silver-oxygen interactions perturb the tetrahedron of the arsenate group, resulting in As-O distances ranging from 1.670 to 1.697 Å, and angles varying from 107.3 to 112.1 ◦ . Pure Ag 13 I 4 (AsO 4 ) 3 is a solid ion conductor with a r. t. conductivity of 6.4×10 −6 Ω −1 cm −1 at 30 ◦ C. The activation energy for silver ion conduction is 0.41 eV in the temperature range from 30 to 130 ◦ C Graphical Abstract Ag 13 I 4 (AsO 4 ) 3 : Synthesis, Crystal Structure and Ionic Conductivity

The arsenite chloride Ce 3 OCl[AsO 3 ] 2 was synthesized in the form of colorless crystals from arsenic and cerium dioxide in a NaCl / KCl flux at 850 ◦ C. Ce 3 OCl[AsO 3 ] 2 crystallizes with the noncentrosymmetric tetragonal Gd 3 OCl[AsO 3 ] 2 type, space group P4 2 nm. The structure was refined from single crystal diffractometer data: a = 12.8590(6), c = 5.5627(3) Å, wR2 = 0.0429, 1463 F2 values, and 65 variables. The structure is built up from chains of trans edge-sharing OCe 4/2 tetrahedra. The [AsO 3 ] 3− units coordinate to these chains via the oxygen atoms. Their lone-pairs point all to a common channel. Formation of the non-centrosymmetric superstructure is most likely driven by geometrical constraints and is discussed on the basis of a group-subgroup scheme Graphical Abstract Non-centrosymmetric Ce 3 OCl[AsO 3 ] 2

The aluminide CeRuAl with orthorhombic LaNiAl-type structure contains two crystallographically independent cerium sites which both exhibit relatively short Ce-Ru distances, i. e. 280 - 302 pm for Ce1 and 286 - 310 pm for Ce2. Susceptibility measurements show intermediate valence behavior of the cerium atoms (1.19(1) μ B per formula unit) and no magnetic ordering down to 2 K. Chemical bonding analysis reveals a non-magnetic ground state and strong Ce-Ru bonding. The Ce-Ru bonding peculiarities of CeRuAl are discussed in line with those of other binary and ternary cerium- ruthenium compounds Graphical Abstract Unusually Short Ce–Ru Distances in CeRuAl and Related Compounds

The crystal structure of the new ternary antimonide Ho 5 GaSb 3 has been determined from X-ray single-crystal data: space group Pnma, a = 7.9667(8), b = 15.128(2), c = 7.9616(8) Å , V = 959.5(3) Å 3 , Z = 4, R F = 0.059, R w = 0.066 for 9020 reflections. The crystal structure of Ho5GaSb3 is a ternary derivative of the Sm 5 Ge 4 structure type with partially ordered distribution of gallium and antimony atoms Graphical Abstract Crystal Structure of the New Ternary Antimonide Ho 5 GaSb 3

Solid solutions Ga 1−x Ge x V 4 S 8 (x = 0−1) were synthesized by solid-state reactions and characterized by temperature-dependent X-ray powder diffraction and static magnetic susceptibility measurements. The compounds crystallize in the cubic GaMo 4 S 8 -type structure (space group F43m), built up by heterocubane-like [V 4 S 4 ] (5−x)+ cubes and [Ga 1−x Ge x S 4 ] (5−x)− tetrahedra arranged in a NaCllike manner. The successive substitution of Ga 3+ by Ge 4+ increases the electron count in the molecular orbitals (MO’s) of the V4-cluster gradually from seven to eight. We observe an almost linear increase of the magnetic moments, connected with a transition from ferromagnetic to antiferromagnetic ordering around x ≈ 0.5. Remarkably, low-temperature structural phase transitions as known from the ternary compounds were also detected in the solid solutions. The gallium-rich compounds (0 ≤ x < 0.5) undergo rhombohedral distortions like GaV 4 S 8 (space group R3m), whereas distortions to orthorhombic symmetry (space group Imm2) as known from GeV 4 S 8 occur in the germanium-rich part of the solid solutions (0.5 ≤ x ≤ 1) Graphical Abstract Low-temperature Crystal Structures and Magnetic Properties of the V 4 -Cluster Compounds Ga 1-x Ge x V 4 S 8

The compounds Pr 6 (C 2 )Br 10 , Pr 10 (C 2 ) 2 Br 15 and Pr 14 (C 2 ) 3 Br 20 were prepared from PrBr 3 and the appropriate amounts of Pr and C and characterized by X-ray structure analyses of single crystals. All three compounds crystallize in space group P1 with lattice parameters a = 7.571(2), b = 9.004(2), c = 9.062(2) Å ,α = 108.57(3), β = 97.77(3), γ = 106.28(3) ◦ for Pr 6 (C 2 )Br 10 ; a = 9.098(2), b = 10.127(2), c = 10.965(2) A° , α = 70.38(3), β = 66.31(3), γ = 70.84(3) ◦ for Pr 10 (C 2 ) 2 Br 15 ; a = 9.054(2), b = 10.935(2), c = 13.352(3) Å , α = 86.27(3), β = 72.57(3), γ = 66.88(3) ◦ for Pr 14 (C 2 ) 3 Br 20 . They are members of a general series Ln 4n+2 (C 2 ) n Br 5n+5 and isostructural with the corresponding iodides known for Ln = La, Ce, Pr. Pr 6 (C 2 )Br 10 was further characterized via transmission electron microscopy techniques Graphical Abstract The Starting Members of the Series Pr 4n+2 (C 2 ) n Br 5n+5 (n = 1, 2, 3)

Graphical Abstract Ionic Liquid-assisted Solvothermal Synthesis of Ni Particles and Study of Their Electrocatalytic Effect for Calcium Dobesilate Oxidation

A series of 2-(2-aminophenyl)-4-arylquinazoline derivatives (5a - j), with various 4-substituents, have been synthesized by one-pot cyclization in 66 - 79% yield by heating 2-aminoarylbenzimidamides 3a - j with isatoic anhydride (4). The high yield and simplified workup procedure, in addition to the neutral reaction conditions, are the main advantages of our approach. The structure of the product 5e was further confirmed by single-crystal X-ray structure analysis Graphical Abstract Synthesis of 2-(2-Aminophenyl)-4-arylquinazoline Derivatives by Reaction of 2-Aminoarylbenzimidamides with Isatoic Anhydride

Crystallization of silver di(4-methylbenzenesulfonyl)amide [Ag(MA)], silver di(4-nitrobenzenesulfonyl) amide [Ag(NA)], silver di(4-bromobenzenesulfonyl)amide [Ag(BA)] or silver di(4-fluorobenzenesulfonyl) amide [Ag(FA)] from acetonitrile solutions under slightly different conditions afforded single crystals of the following complexes, which were structurally authenticated by X-ray diffraction at low temperatures: (MeCN)Ag(MA) (1, triclinic, space group P1, Z’ = 1), (MeCN) 2 Ag(NA) (2, monoclinic, P2 1 /c, Z’ = 1), (MeCN) 2 Ag(BA) (3, monoclinic, P2 1 /c, Z’ = 1), (MeCN) 2 Ag(BA) (4, monoclinic, P21/c, Z’ = 2), and [(MeCN) 3 Ag][Ag(FA) 2 ]・MeCN (5, triclinic , Z’ = 1). In each structure, the inner coordination sphere of silver is formed by the ligand nitrogen atoms, leading to a linear NAgN core for the molecular complex 1 and the complex anion of 5, or to a trigonal planar AgN 3 core for the molecular complex 2, the molecular polymorphs 3 and 4, and the complex cation of 5. The flexible di(arenesulfonyl)amide ligands adopt extended pseudo-C 2 symmetric conformations in 1, 2 and 5, but folded pseudo-mirror symmetric conformations in 3 and 4. The molecules of 1 are associated into inversion-symmetric dimers via a short Ag・ ・ ・O contact; the dimers form stacks by translation along the a axis, causing the silver ions to segregate in zigzag chains. The arrangement of the molecules in 2 is controlled mainly by a centered C-H・ ・ ・Ph hydrogen bond, a dipolar nitro-nitro and a dipolar nitro-sulfonyl interaction, giving rise to layers oriented parallel to the bc plane. The packing motifs of polymorphs 3 and 4 are very similar. Both forms consist of layers in which the molecules act as 4-connecting nodes in a network based upon C-Br・ ・ ・O=S halogen bonds. In the Z’ = 1 structure of 3, the layers are generated by 2 l screw axes and display one short and one long halogen bond, whereas in the Z’ = 2 structure of 4, the layers are realized by glide planes and are based on four independent halogen bonds that are all reasonably short. The packing of 5 exhibits alternating layers comprised of complex anions or of complex cations and acetonitrile solvent molecules, respectively. This Z’ = 2 structure may be viewed as a kinetic polymorph of a more symmetric Z’ = 1 crystal Graphical Abstract Polysulfonylamine, CLXXXVII [1]. Strukturvielfalt in (Acetonitril)silber(I)-di(arensulfonyl)amiden: Zwei Molek¨ulkristalle mit Z'= 1, ein Ionenkristall mit Z' = 2 und zwei auf Halogenbr¨ucken C–Br···O=S beruhende molekulare Polymorphe mit Z' = 1 beziehungsweise Z' = 2 in der gleichen Raumgruppe / Polysulfonylamines, CLXXXVII. Structural Diversity in (Acetonitrile)silver(I) Di(arenesulfonyl)- amides: Two Molecular Z' = 1 Crystals, an Ionic Z' = 2 Crystal, and Two Molecular Polymorphs Based upon C–Br· · ·O=S Halogen Bonds and Featuring Z' = 1 or Z' = 2 in the Same Space Group

Since the amino and the hydroxyl groups of 4-(2-hydroxyphenyl)-2-phenyl-2,3-dihydro-1H-1,5- benzodiazepine can both act as nucleophiles, the introduction of both an N-acetyl and an O-acetyl group is expected when the compound is allowed to react with an excess of an electrophile such as acetic anhydride. An intramolecular hydrogen bond between OH and N-5 of the benzodiazepine has been used to obtain differentiation between the two possible sites of acetylation. Thus, this feature offers a preparatively utilizable protecting effect for the OH group and allows for a regioselective N-acetylation at ambient temperature. Both mono- and diacetylated compounds were prepared and characterized by crystal structure analysis Graphical Abstract Regioselective N-Acetylation of 4-(2-Hydroxyphenyl)-2-phenyl-2,3- dihydro-1H-1,5-benzodiazepine Using Protection by an Intramolecular Hydrogen Bond

4-Alkylamino-2-chloroquinoline-3-carbonitriles 4a - c react with NaN 3 to give the corresponding tetrazolo[1,5-a]quinoline-4-carbonitriles 5a - c which are converted into 2-amino-quinoline-3-carbonitriles 8a - c by reaction with PPh 3 via an iminophosphorane and subsequent hydrolysis. On the other hand, the new 3,4-diamino-1H-pyrazolo[4,3-c]quinoline (11) was prepared by fusion of the aminoquinolines 8a - c with hydrazine hydrate. Diazotization of 11 followed by reaction with NaN 3 yielded the novel tetracyclic ring system 3-azido-1H-1,2,4,5,6,6a-hexaazabenzo[a]indacene (13) Graphical Abstract Fused Quinoline Heterocycles IX: First Example of a 3,4-Diamino-1H-pyrazolo[4,3-c]quinoline and a 3-Azido-1H-1,2,4,5,6,6a-hexaazabenzo[a]indacene

Various 2-(α-hydroxyalkyl)cyclopropanols were generated by chromium(II)-mediated crosscoupling of acroleins and aldehydes with high diastereoselectivities up to 95%. The unstable diols were converted selectively to the stable monosilyl ethers by treatment with TBDMS-Cl in the presence of the second secondary alcohol Graphical Abstract Diastereoselective Formation of Cyclopropanols by a Chromium(II)-mediated Cross-coupling Reaction

The cobalt complex [{K(18-crown-6)} 2 (C 5 H 5 )]- [Co(C 8 H 12 ) 2 ]・(THF) 2 (3) has been synthesized and characterized by X-ray single-crystal structure determination. The crystal structure of Co(C 8 H 12 )(C 8 H 13 ) (2) has been reinvestigated and compared with the structure of 3. The 1,5-cyclooctadiene (C 8 H 12 ) and C 8 H 13 ligands are coordinated in an η 4 and η 3 fashion, respectively. The cyclopentadienyl anion in [{K(18-crown-6)} 2 (C 5 H 5 )]+ in 3 is η 5 -coordinated to the two crown ether-encapsulated potassium cations Graphical Abstract The Anion [Co(C 8 H 12 ) 2 ]–. A Comparative Study of the Crystal Structures of [{K(18-crown-6)} 2 (C 5 H 5 )][Co(C 8 H 12 ) 2 ] and Co(C 8 H 12 )(C 8 H 13 )