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The reactions of cadmium bromide and cadmium iodide with pyridazine (C4H4N2) in ethanol under solvothermal conditions led to the formation of crystals of [CdBr2(pyridazine)]n (1) and [CdI2(pyridazine)]n (2), which were characterized by single-crystal X-ray diffraction. The asymmetric units of both compounds consist of a cadmium cation located on the intersection point of a twofold screw axis and a mirror plane (2/m), a halide anion that is located on a mirror plane and a pyridazine ligand, with all atoms occupying Wyckoff position 4e (mm2). These compounds are isotypic and consist of cadmium cations that are octahedrally coordinated by four halide anions and two pyridazine ligands and are linked into [100] chains by pairs of μ-1,1-bridging halide anions and bridging pyridazine ligands. In the crystals, the pyridazine ligands of neighboring chains are stacked onto each other, indicating π–π interactions. Larger amounts of pure samples can also be obtained by stirring at room-temperature, as proven by powder X-ray diffraction. Measurements using thermogravimetry and differential thermoanalysis (TG-DTA) reveal that upon heating all the pyridiazine ligands are removed in one step, which leads to the formation of CdBr2 or CdI2.

The reactions of cadmium bromide and cadmium iodide with pyridazine (C4H4N2) in ethanol under solvothermal conditions led to the formation of crystals of [CdBr2(pyridazine)]n (1) and [CdI2(pyridazine)]n (2), which were characterized by single-crystal X-ray diffraction. The asymmetric units of both compounds consist of a cadmium cation located on the intersection point of a twofold screw axis and a mirror plane (2/m), a halide anion that is located on a mirror plane and a pyridazine ligand, with all atoms occupying Wyckoff position 4e (mm2). These compounds are isotypic and consist of cadmium cations that are octahedrally coordinated by four halide anions and two pyridazine ligands and are linked into [100] chains by pairs of μ-1,1-bridging halide anions and bridging pyridazine ligands. In the crystals, the pyridazine ligands of neighboring chains are stacked onto each other, indicating π-π interactions. Larger amounts of pure samples can also be obtained by stirring at room-temperature, as proven by powder X-ray diffraction. Measurements using thermogravimetry and differential thermoanalysis (TG-DTA) reveal that upon heating all the pyridiazine ligands are removed in one step, which leads to the formation of CdBr2 or CdI2. [ABSTRACT FROM AUTHOR]

The co-pyrolysis tar formed from microcrystalline cellulose (MCC) and polyethylene (PE) was used to study their further conversion path under the effect of steam. This paper addressed the yield and transformation of tar with different steam/feedstock mass ratios (S/F= 0.8, 1.6) in a two-stage fixed bed when the two stages' furnace temperature was set at 600°C and 800°C, separately. Compared with pyrolysis, steam promoted tar cracking effectively, the tar yield decreased at least 1/3. However, when the S/F ratio increases to 1.6, the cracking effect of tar is not further improved. The tar yield depended more on the PE content in the mixture, which was enhanced with PE increment. Besides, the H/C atom ratio was related to the conversion path of tar. Steam was beneficial to the cracking of compounds, but the generated hydrogen radicals affected the direction of the subsequent reaction. The steam mainly promotes the cracking of long-chain hydrocarbons, accompanied by cyclization and aromatization when the steam was limited. Nevertheless, the chain compounds are hard to crack efficiently when the steam was excessive, and the cyclization and aromatization processes were hindered due to the apparent effect of hydrogenation. [ABSTRACT FROM AUTHOR]

The asymmetric unit of the title compound, {[Mn2Sb2S5(C15H11N3)2]·4H2O}n, consists of two crystallographically independent MnII ions, two unique terpyridine ligands, one [Sb2S5]4− anion and four solvent water molecules, all of which are located in general positions. The [Sb2S5]4− anion consists of two SbS3 units that share common corners. Each of the MnII ions is fivefold coordinated by two symmetry-related S atoms of [Sb2S5]4− anions and three N atoms of a terpyridine ligand within an irregular coordination. Each two anions are linked by two [Mn(terpyridine)]2+ cations into chains along the c-axis direction that consist of eight-membered Mn2Sb2S4 rings. These chains are further connected into a three-dimensional network by intermolecular O—H...O and O—H...S hydrogen bonds. The crystal investigated was twinned and therefore, a twin refinement using data in HKLF-5 [Sheldrick (2015). Acta Cryst. C71, 3–8] format was performed.

The asymmetric unit of the title compound, {[Mn2Sb2S5(C15H11N3)2]·4H2O}n, consists of two crystallographically independent Mn ions, two unique terpyridine ligands, one [Sb2S5]4- anion and four solvent water molecules, all of which are located in general positions. The [Sb2S5][sup 4-] anion consists of two SbS3 units that share common corners. Each of the MnII ions is fivefold coordinated by two symmetry-related S atoms of [Sb2S5]4- anions and three N atoms of a terpyridine ligand within an irregular coordination. Each two anions are linked by two [Mn(terpyridine)]2+ cations into chains along the c-axis direction that consist of eight-membered Mn2Sb2S4 rings. These chains are further connected into a three-dimensional network by intermolecular O--H⋯O and O--H⋯S hydrogen bonds. The crystal investigated was twinned and therefore, a twin refinement using data in HKLF-5 [Sheldrick (2015). Acta Cryst. C71, 3-8] format was performed. [ABSTRACT FROM AUTHOR]

Chain compounds of paddle-wheel Cu2-clusters of 3-carboxy-2,2,5,5-tetramethyl- 1-pyrrolidinyloxy (Hcaproxy) and 4-carboxy-2,2,6,6-tetramethylpiperidinyloxy (Hcatempo) and N,N'-bidentate ligands (L = 4,40-bipyridine (4,40-bpy), 1,2-bis(4-pyridyl)ethane (bpe), trans-1,2-bis(4-pyridyl)ethylene (bpel), 4,40-dipyridyl disulfide (pds), 1,4-diazabicyclo[2.2.2]octane (dabco), and pyrazine (pyz)), [Cu2(caproxy)4(L)]n, and [Cu2(catempo)4(L)]n, were synthesized and characterized by elemental analysis, infrared and UV-vis spectra and temperature dependence of magnetic susceptibilities (4.5-300 K). The crystal structures of [Cu2(caproxy)4(pds)]n, [Cu2(catempo)4(4,40-bpy)]n, and [Cu2(catempo)4(bpe)]n revealed zigzag or linear chains consisting of alternate arrangement of the dinuclear cluster bearing four nitroxide radicals and N,N'-bidentate ligand. Temperature dependence of magnetic susceptibilities showed a considerable antiferromagnetic interaction between the two copper(II) ions within the dinuclear cluster, and weak antiferromagnetic interaction between the dinuclear clusters and/or the radical and dinuclear cluster. [ABSTRACT FROM AUTHOR]

The incorporation of amino-substituted benzoquinoid bridging ligands into extended solids may provide a route to access light-weight metal-organic solids with high-temperature magnetic behavior and electronic conductivity. Reaction of Zn(NO 3 ) 2 ·6H 2 O with 2,5-diamino-3,6-dibromo-1,4-benzoquinone ( Br LH 2 ) in DMF at 130 °C gave a black crystalline solid of the compound Zn( Br L)(DMF), which features a structure comprised of one-dimensional chains made up of alternating Zn II ions and Br L 2− bridging ligands. The preservation of NH groups on Br L 2− was confirmed by X-ray crystallography, a suite of spectroscopic measurements, and elemental analysis. To our knowledge, this chain compound represents the first structurally-characterized solid that contains amino-substituted benzoquinoid bridging ligands. Finally, an ambient temperature electronic conductivity value of σ = 1.076(5) × 10 −12 S·cm −1 was measured for the chain compound. [ABSTRACT FROM AUTHOR]

Abstract: The synthesis, crystal structure, as well as the electronic and magnetic properties, of a new trinuclear-based Cu(II) compound [Cu3(μ-aapm)2(μ-dca)2(Haapm)2](CF3SO3)2, containing the ligands N-(pyridin-2yl)acetamide (Haapm) and dicyanamide (dca) is reported. The central Cu1 atom has a distorted elongated octahedral coordination with the basal plane comprised of two nitrogens from two different tetrachelating dehydronated aapm ligands and two nitrogen atoms of two dca anions (Cu–N distances 2.016(2) and 1.988(3)Å). The apical positions are occupied by two nitrogen atoms of the two different tetrachelating aapm ligands (Cu–N distance 2.539(3)Å), with a trans angle of 180°. Also the N–Cu–N angle is extremely small (58.25(9)°), due to the four-membered chelate ring. The outer Cu2 ions have also a distorted octahedral geometry with the basal plane formed of two nitrogens and two oxygen atoms from a tetrachelating dehydronated aapm ligand (which is bridging between Cu1 and Cu2) and from a Haapm ligand (Cu–N/O distances vary from 1.95.4(2) and 2.022(2)Å), with basal angles of 177.29(9)° and 171.12(8)°. The apical positions are occupied by an oxygen atom of a triflate anion (Cu–O distance 2.534(3)Å) and a nitrogen atom of a neighbouring dca anion (Cu–N distance 2.314(3)Å), with an angle of 171.92(8)°. The Cu–Cu distance within the trinuclear unit is 5.23Å. The dca anions are connected in an end-to-end fashion to a neighbouring Cu(II) ion (Cu–Cu distance 8.54Å), forming in this way a chain of trinuclear units bridged by two dca anions. The EPR as a powdered solid revealed a weak S =1 triplet spectrum at RT. The magnetic susceptibility measurements, measured from 5 to 200K, revealed a weak ferromagnetic interaction between the Cu(II) ions. [Copyright &y& Elsevier]

The asymmetric unit of the title compound, {[Mn 2 Sb 2 S 5 (C 15 H 11 N 3 ) 2 ]·4H 2 O} n , consists of two crystallographically independent Mn II ions, two unique terpyridine ligands, one [Sb 2 S 5 ] 4- anion and four solvent water mol-ecules, all of which are located in general positions. The [Sb 2 S 5 ] 4- anion consists of two SbS 3 units that share common corners. Each of the Mn II ions is fivefold coordinated by two symmetry-related S atoms of [Sb 2 S 5 ] 4- anions and three N atoms of a terpyridine ligand within an irregular coordination. Each two anions are linked by two [Mn(terpyridine)] 2+ cations into chains along the c -axis direction that consist of eight-membered Mn 2 Sb 2 S4 rings. These chains are further connected into a three-dimensional network by inter-molecular O-H⋯O and O-H⋯S hydrogen bonds. The crystal investigated was twinned and therefore, a twin refinement using data in HKLF-5 [Sheldrick (2015 ▸). Acta Cryst. C 71 , 3-8] format was performed., (© Danker et al. 2020.)