Search

Abstract: A novel organic–inorganic coordination polymer [CdCl3(CH3)3NH] 1 was synthesized by the reaction of CdCl2 with trimethylamine (TMA) at 170 °C for 5 days in ethanol and structurally characterized by means of X-ray single diffraction. The title compound affords a one-dimensional chain structure. It crystallizes in hexagonal system space group with , , , , , , , , , , the final and for 355 observed reflections with . The title compound consists of cation [(CH3)3NH]+ and anion chain , and they are combined by static attracting forces in the crystal. TG–DTA, XRD and IR data for the title compound are reported and discussed. The photoluminescent properties of the compound 1 were also investigated. [Copyright &y& Elsevier]

Abstract: Vibrational and electronic spectral measurements were made for 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ). Optimized geometrical structure and harmonic vibrational frequencies were computed by DFT(B3LYP, CAMB3LYP, B3P86, M062X, mPW3PBE and PBE1PBE) using 6-311++G(d,p) basis set. Complete assignments of the observed spectra were proposed. The absorption spectra of the compound were computed both in gas-phase and in CH2Cl2 solution using TDCAMB3LYP/6-311++G(d,p) and PCM-TDCAMB3LYP/6-311++G(d,p) approaches, respectively, the calculated results provide a good description of positions of the bands maxima in the observed electronic spectrum. [Copyright &y& Elsevier]

Abstract: Four new cyano-substituted styryl derivatives based on carbazole and phenothiazine were facilely synthesized by conventional Knoevenagel condensation and well characterized. The UV–vis spectra of these dyes showed the lowest-energy absorption bands were mainly caused by the HOMO–LUMO one-electron promotion as conformed by TD-DFT calculations. The thermogravimetric analysis showed these dyes were thermally stable up to 350°C. The UV–vis absorption and fluorescence emission spectra were also studied in solvents of different polarity, these dyes exhibited unusual large Stokes shift. [Copyright &y& Elsevier]

The title compound (CHO·CHN)·0.5HO 1 was isolated from solvothermal synthesis of 4′-(4-pyridyl)-2,2′:6′,2′-terpyridine (pytpy) and trimesic acid (1,3,5-benzenetricarboxylic acid, HBTC). It was characterized by element analysis, IR, TGA, XRD, X-ray single-crystal diffraction, and spectroscopy properties, together with quantum chemistry calculation of spectrum (UV-vis spectra) through the method b3lyp/6-31 t g (d,p) are also investigated. Single-crystal X-ray diffraction shows 1 possesses a 3-D supramolecular network with 1-D six-fold helical double chains built from protonated (Hpytpy) $_{n}^{3+}$ cations and deprotonated (BTC) $_{n}^{3-}$ anions. The maximum of the fluorescent emission bands of 1 is located at 427 nm ( λ = 266 nm), with a shoulder at about 390 nm. The result of theoretic calculations confirms that 1 has small HOMO-LUMO energy gap (1.24 eV) and high chemical reactivity. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

Abstract: Two novel conjugated imino-π-extended tetrathiafulvalenes with p-iminobenzene, N,N′-bis(4,5-bis(methylthio)-1,3-dithiol-2-ylidene)benzene-1,4-diamine (1) and N,N′-bis(4,5-bis(ethylenedithio)-1,3-dithiolo-2-ylidene)benzene-1,4-diamine (2), have been synthesized and characterized by NMR, IR, MS and X-ray single-crystal diffraction. Both the two targets adopt chair-like conformation, and the central rings of p-iminobenzene moieties of the two molecules are severely twisted from the planarity of two dithiole rings, respectively. The UV–vis spectra of 1 and 2 show the lowest-energy absorption bands caused by the HOMO–LUMO one-electron promotion. Cyclic voltammetry (CV) measurements show only one, two-electron irreversible oxidation picks. These experimentally estimated energy levels of the frontier orbital of 1 and 2 (E HOMO 1: = −5.45, 2: −5.47 eV) are in good agreement with those obtained from DFT calculations (E HOMO 1: = −5.5, 2: = −5.3eV). The high HOMO–LUMO gaps of 1 (4.05eV) and 2 (4.00eV) indicate high kinetic stability of the title compounds. [Copyright &y& Elsevier]

Animal manures usually contain high contents of heavy metals (HMs) and thus pose a considerable threat to human health and environment when applied to soil. In this study, the effect of pyrolysis temperature (300 °C, 400 °C, 500 °C, 600 °C, and 700 °C) on the properties of biochar produced from chicken manure was studied. In addition, the response of speciation, bioavailability, leachability, and environmental risk of HMs in biochar to different pyrolysis temperature was investigated. The results showed that biochars pyrolyzed at high temperatures generally had high pH, ash content, surface area, and stability. As the pyrolysis temperature increased, the total concentrations of Cu, Zn, Cr, and Ni continually increased, whereas those of Pb and Cd initially increased and then decreased. Moreover, the transformation of the bioavailable fractions of HMs into stable fractions obviously increased with increasing pyrolysis temperature. Thus, pyrolysis at high temperature led to a further decrease in the bioavailability, leachability, and environmental risk of six HMs, as shown by DTPA, TCLP, and the potential ecological risk index. Overall, it is convincing that that 700 °C is the optimal temperature when considering the quality and environmental safety of biochar derived from chicken manure. [ABSTRACT FROM AUTHOR]

• Swine manure was pretreated by NaOH to obtain the resultant biochars. • The addition of NaOH enhanced the aromaticity and hydrophily of biochars. • The addition of NaOH promoted the immobilization of Cu, Zn, Cr, Pb and Cd. • The addition of NaOH reduced the leachability and ecological risks of heavy metals. In order to improve characteristics of biochar, especially enhance immobilization of heavy metals in biochar, swine manure was pyrolyzed at low pyrolysis temperature (300 °C, 400 °C and 500 °C) with different amounts of sodium hydroxide (NaOH) added (0.5% and 2%, W/W). Results showed that NaOH addition during pyrolysis increased the pH, EC, ash content, yield rate, aromaticity and hydrophily, but did not increase surface area and porosity of resultant biochars. The addition of NaOH promoted the transformation of the mobile fraction of Cu, Zn and Cd into the oxidizable fraction. With respect to Cr and Pb, the oxidizable and residual fractions were increased slightly by the presence of NaOH. Meanwhile, adding NaOH could reduce the leachability and ecological risks of heavy metals in biochars. Our study suggested that NaOH-assisted pyrolysis of swine manure was an effective disposal approach for the immobilization of heavy metals. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • 0.3-AgI/BiVO 4 exhibits excellent photocatalytic performance. • The band structure was revealed via the CASTEP, and valence band XPS. • The simultaneous photocatalytic oxidation and reduction enhancing mechanism was discussed. Abstract Simultaneous combination of photocatalytic oxidation of tetracycline (TC) and reduction of Cr(VI) over the AgI/BiVO 4 p-n junction photocatalysts were studied systematically. The result showed that the pollutant degradation efficiency of the photocatalyst was greatly enhanced when the system contained both TC and Cr(VI) compared to that containing Cr(VI) or TC alone. It is proposed that the co-existence of oxidizable and reducible species, such as TC and Cr(VI), ensured efficient use of the photoinduced electrons and holes, which leaded high efficiencies for both TC oxidation and Cr(VI) reduction. Among these photocatalysts, the 0.3-AgI/BiVO 4 exhibits excellent photocatalytic activity, which is ascribed to the increased lifetime of the charge carriers confirmed by the result of time-resolved fluorescence emission decay spectra. In addition, seven degradation products of TC were found by GC–MS. Moreover, the band structure of the photocatalyst was obtained by the DFT calculation, VB-XPS spectra and the values of the Fermi level obtained by CASTEP. Finally, simultaneous photocatalytic oxidation and reduction enhancing mechanism over the AgI/BiVO 4 photocatalyst was discussed in detail. The strategy of forming novel p-n junction photocatalyst for both the Cr(VI) reduction and TC oxidation will benefit the development of the other new photocatalysts for the purpose of controlling and improving the environment. [ABSTRACT FROM AUTHOR]

The crystal structure of a new coordination compound tri(2-(2,6-dichlorophenyl)-1H-imidazo[4,5-f][1,10]phenanthroline) Co(II) complex ([Co(dcpip) 3 ]Cl 2 ) was measured with X-ray diffraction measurements. The compound is crystallizes triclinic, Pī space group. The ligand, 2-(2,6-dichlorophenyl)-1H-imidazo[4,5-f][1,10]phenanthroline(dcpip), binds to Co(II) ions with a bis-dentate mode, and each Co(II) ion with a distorted octahedral coordination geometry. The calculated interaction energies of Co(II) with coordination atoms N are between 101.7–206.5 kJ/mol and 115.3–230.9 kJ/mol for B3LYP/6-31+G ∗ and PBE1PBE/6-31+G ∗ theoretical methods, respectively. The experimental Fourier transform infrared spectrum was assigned. The calculated IR based on B3LYP/6-31+G ∗ and PBE1PBE/6-31+G ∗ methods were performed and compared with experimental results. The UV–Vis experimental spectrum of [Co(dcpip) 3 ]Cl 2 was measured in methanol solution. The calculated electronic spectrum was performed with TD/B3LYP and TD/PBE1PBE methods with 6-31+G ∗ basis set. The first and second order hyperpolarizability for the compound was calculated. The calculated values of γ tot are −1.5551344 × 10 −33 esu for B3LYP method and −1.3323259 × 10 −33 esu for PBE1PBE method. The nature bond orbital analysis and temperature dependence of the thermodynamic properties were calculated with the same methods. [ABSTRACT FROM AUTHOR]

The compound 9-p-tolyl-9H-carbazole-3-carbaldehyde (HCCD) was synthesized and characterized by X-ray diffraction, FT-IR, FT-Raman and UV–Vis spectra. The X-ray diffraction study showed that HCCD has a Z-configuration. The benzene ring including methyl is twisted from the mean plane of the carbazole group by 59.7(3)°, which is comparable with the calculated result 65° for B3LYP/6-311++G(d, p) method. Vibrational spectra and electronic spectra measurements were made for the compound. Optimized geometrical structure and harmonic vibrational frequencies were computed with B-based DFT (BLYP, B3LYP and cam-B3LYP) methods, and WB-based DFT (WB97, WB97X and WB97XD) methods and ab initio RHF method using 6-311++G(d, p) basis set. Assignments of the observed spectra were proposed. The equilibrium geometries computed by all of the methods were compared with X-ray diffraction results. The absorption spectra of the title compound were computed both in gas phase and in DMF solution using TD-(cam)B3LYP/6-311++G(d, p) and PCM-(cam)B3LYP/6-311++G(d, p) approaches, respectively. The calculated results provide good descriptions of the bands maxima in the observed electronic spectrum. Temperature dependence of thermodynamic parameters in the range of 100–1000 K was determined. The natural atomic hybrids were calculated and discussed. [ABSTRACT FROM AUTHOR]

Highlights: [•] The FT-IR, FT-Raman spectra and UV–Vis of the title compound have been recorded experimentally. [•] Optimized geometry, vibrational frequencies, IR and Raman intensities are obtained with RHF and six DFT methods. [•] The complete assignments of the experimental spectra are performed on the basis of the potential energy distribution (PED). [•] The absorption spectra of the compound were computed both in gas-phase and in DMF solution. [Copyright &y& Elsevier]

Highlights: [•] The FT-IR, FT-Raman spectra and UV–vis of the title compound have been recorded experimentally. [•] Optimized geometry, vibrational frequencies are obtained with six DFT methods. [•] The complete assignments of the experimental spectra are performed on the basis of PED. [•] The HOMO and LUMO energies have been calculated. [•] The absorption spectra of the compound were computed both in gas-phase and in H2O solution. [Copyright &y& Elsevier]

• g-C 3 N 4 /SnS 2 shows superior photocatalytic activity for the removal of Cr6+ and BPS. • The photocatalytic degradation pathway of BPS is proposed based on the result of GC–MS. • DFT displays the band distribution of g-C 3 N 4 /SnS 2 is staggered near the forbidden. • Z-scheme photocatalysis mechanism is proposed based on the results of experiments and simulations. A novel 2D/3D Z-scheme g-C 3 N 4 /SnS 2 photocatalyst was successfully fabricated via self-assembly forming 3D flower-like SnS 2 microspheres on the surface of the 2D g-C 3 N 4 nanosheets. The photocatalytic performances of the samples were systematically explored through catalytic reduction of Cr6+ and oxidation of Bisphenol S (BPS) under the illumination of visible light, and the photocatalytic degradation pathway of BPS was also proposed based on the degradation products confirmed by GC MS. Among the as-prepared samples, 0.4-g-C 3 N 4 /SnS 2 exhibited the most efficient photocatalytic performances, and the apparent quantum efficiency (QE) for the removal of Cr6+ could achieve 30.3 %, which is 2.8 times higher than that of the SnS 2. The enhancing photocatalytic activities originated from the efficient interfacial charge migration and separation obtained in g-C 3 N 4 /SnS 2 , which was firstly verified via the photoluminescence spectra, time-resolved photoluminescence spectra and photoelectrochemical characterizations. Importantly, the DFT calculated shows that the band distribution of the g-C 3 N 4 /SnS 2 sample is staggered near the forbidden, which can facilitate the efficient interfacial charge migration and separation as well as result in the improvement of the catalytic activity. Finally, we put forward a more reasonable Z-scheme charge transfer mechanism, it was verified by analysing the results of free radical scavenging tests, EPR experiments and theoretical calculations. [ABSTRACT FROM AUTHOR]