Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 7 de 7
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Sci Rep ; 5: 17344, 2015 Dec 09.
Artigo em Inglês | MEDLINE | ID: mdl-26648133

RESUMO

Exploration of new spin systems with low-dimensional subunits have been of great interest in the past decades due to their interesting physical properties and potential applications in molecular spintronics. Two inorganic supramolecular complexes, (Hg3S2)(FeCl4) and (Hg3S2)(CoCl4), with trigonally aligned 1-D infinite magnetic ∞(1)(FeCl4)(2-) or ∞(1)(CoCl4)(2-) chains have been prepared by solid-state reactions. They exhibit 3-D long-range spin order with strong field dependence and field induced metamagnetic behavior. The intrachain and interchain magnetic coupling constants were estimated by DFT+U and DFT+U+SOC calculations and the both complexes can be regarded as partially frustrated spin systems. The spin Hamiltonian was constructed, the ground state is proposed to be incommensurate spiral spin order, which differs from the commensurate 120° spin structure ground state of fully frustrated trigonal case by a little canted angle. This study shows that cooperative magnetic ordering induced by geometric frustration can be realized in inorganic supramolecular systems assembled by weak van der Waals' interactions.

2.
Dalton Trans ; 44(21): 10089-96, 2015 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-25952460

RESUMO

Two new lead(II) coordination polymers, [Pb(NO3)(tzib)]n (1) and [Pb(tzib)2]n (2), were successfully synthesized from the reaction of a rigid ligand 1-tetrazole-4-imidazole-benzene (Htzib) and lead(II) nitrate in different solvents. The obtained polymers have been characterized by single-crystal X-ray diffraction analyses, which show that both polymers feature 2D layer structures. The inorganic anion nitrate in 1 shows a µ2-κO3:κO3 bridging mode to connect adjacent lead ions into a zigzag chain, and then the organic ligands tzib(-) join the neighboring chains into a 2D layer by a µ3-κN1:κN2:κN6 connection mode. In 2, there are two different bridging modes of the tzib(-) ligand: µ3-κN1:κN2:κN6 and µ3-κN1:κN6 to coordinate the lead ions into a 2D layer structure. Interestingly, both polymers displayed broadband emissions covering the entire visible spectra, which could be tunable to near white-light emission by varying excitation wavelengths.

3.
Dalton Trans ; 44(7): 3289-94, 2015 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-25597698

RESUMO

Three air-stable tetrahedral manganese(ii) dihalide complexes [MnX2(DPEPO)] (DPEPO = bis[2-(diphenylphosphino)phenyl]ether oxide; X = Cl, Br and I) were prepared. All of the obtained compounds were structurally characterized by single-crystal X-ray diffraction analyses, which reveal that they crystallize in centrosymmetric space groups and feature an isolated mononuclear structure with Mn(2+) in a tetrahedral environment. Interestingly, these complexes show excellent photoluminescent performance in neat solid form, with the highest total quantum yield (Φtotal) of up to 70% recorded for the dibromide complex. Intense green flashes of light could be observed by the naked eye when rubbing the manganese(ii) complexes.

4.
Inorg Chem ; 52(17): 10096-104, 2013 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-23937409

RESUMO

We employed two pairs of new in-situ-generated chiral amino acid-tetrazole ligands in constructing homochiral Zn(II) coordination compounds: [Zn(tzet)]n (1a for (S)-tzet and 1b for (R)-tzet, H2tzet = N-[2-(1H-tetrazol-5-yl)ethyl]tryptophan) and [Zn(tzep)(H2O)2]·H2O (2a for (S)-tzep and 2b for (R)-tzep, H2tzep = N-[2-(1H-tetrazol-5-yl)ethyl]proline), which were hydrothermally synthesized and structurally characterized by single-crystal X-ray diffraction. Structural analysis reveals that 1 features a 2D homochiral framework generated by both tetrazolate and carboxylate bridges in tzet(2-) ligands. The isolated structure of 2 is stabilized by extensive hydrogen bonds, which leads to formation of a supramolecular 2D architecture. The absolute configuration induced at the nitrogen atoms of 1 and 2 is strictly related to the neighboring chiral carbon atoms by hydrogen-bond interactions. To further investigate their chirality, the combined experimental and theoretical analyses of circular dichroism spectra reveal the absolute configurations and nature of the Cotton effects. Solid-state excitation and emission spectra for 1 and 2 at room temperature were investigated with relevant density of states calculation, and tunable photoluminescence emission of 1 under different excitation wavelengths was discussed. As nitrogen-rich tetrazolate compounds, 1 and 2 possess higher enthalpies of combustion and may serve as a new family of promising energetic materials.

5.
Inorg Chem ; 52(15): 8865-71, 2013 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-23837877

RESUMO

Two new different-bond-type hybrid compounds, (Hg6P4Cl3)(PbCl3) (1) and (Hg23P12)(ZnCl4)6 (2), with supramolecular interactions between host and guest moieties, which based on metal-pnicogen, pnicogen-pnicogen, and metal-halogen bonds were obtained by solid-state reactions. Compounds 1 and 2 show large second-harmonic-generation (SHG) activity and are transparent in the wide mid-IR region, providing an effective route for searching new IR nonlinear-optical material systems by combining two or more different bond types with no IR absorption within a single compound through supramolecular assembly. Theory predications based on first-principles calculations are also performed on the SHG properties of 1 and 2.

6.
Zhonghua Nan Ke Xue ; 14(3): 227-30, 2008 Mar.
Artigo em Chinês | MEDLINE | ID: mdl-18488335

RESUMO

OBJECTIVE: To observe the efficacy and safety of Fushile, a compound preparation of several Chinese herbal drugs, in the treatment of benign prostatic hyperplasia (BPH). METHODS: A multi-centered, open and self-controlled clinical trial was performed in 60 BPH patients, who were treated with Fushile for 12 weeks. The efficacy of the compound was evaluated by the International Prostate Syndrome Score (IPSS), maximum flow rate (Qmax), post void residual (PVR) and prostate volume as the primary indexes and by the quality of life (QOL) score and average urinary flow rate (Qave) as the secondary indexes. RESULTS: After 12 weeks of Fushile treatment, IPSS, Qmax, PVR, QOL and Qave of the BPH patients were significantly improved (P < 0.01), but there was no significant difference in the volume of the prostate before and after the treatment (P > 0.05). No adverse events were observed in any of the patients. CONCLUSION: Fushile can significantly improve voiding symptoms, increase urinary flow and reduce PVR in BPH patients. It is effective and safe in the treatment of BPH.


Assuntos
Medicamentos de Ervas Chinesas/uso terapêutico , Fitoterapia , Hiperplasia Prostática/tratamento farmacológico , Idoso , Combinação de Medicamentos , Medicamentos de Ervas Chinesas/efeitos adversos , Humanos , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento , Micção/efeitos dos fármacos
7.
Artigo em Chinês | MEDLINE | ID: mdl-14761574

RESUMO

OBJECTIVE: To observe changes of plasma polypeptide hormone levels in rats with gastric ulcer after exposure to intense noise, and to discuss their mechanism. METHODS: 80 Wistar rats were used in the study. Plasma levels of rat gastrin (GAS), motilin (MTL), osteocalcin (BGP), substance P (SP), neurotensin (NT) and somatostatin (SS) in rats were measured by radioimmunoassay. RESULTS: (1) In non-noise-exposure but with gastric ulcer group, the plasma MTL [(160.70 +/- 40.34) pg/ml] and BGP [(27.63 +/- 13.13) pg/ml] levels on 10 d after gastric ulcer model operation were remarkably higher than those in control group [(89.21 +/- 49.94) pg/ml, (9.10 +/- 1.38) pg/ml respectively] (P < 0.05 and P < 0.01), while the GAS level was remarkably descended [(107.00 +/- 21.75) vs (158.48 +/- 20.92) pg/ml] (P < 0.01). (2) In noise-exposure but without gastric ulcer group, the plasma MTL [(312.80 +/- 207.42) pg/ml] and BGP [(17.76 +/- 12.33) pg/ml] levels on 10 d were also significantly increased as compared with the control group (P < 0.01 and P < 0.05 respectively), while the GAS levels didn't change. (3) In noise-exposure + gastric ulcer group, the areas of gastric ulcer on 10 d and 40 d after noise and operation [(15.33 +/- 7.26) and (15.11 +/- 12.45) mm(2) respectively] were significantly larger than those of the control [(8.22 +/- 6.66), (3.67 +/- 9.90) mm(2)] (P < 0.05). The plasma MTL levels on 10 d and 40 d [(244.44 +/- 68.11) and (191.20 +/- 60.50) pg/ml respectively] were higher than those in control group [(160.70 +/- 40.34) and (93.10 +/- 52.90) pg/ml respectively] (P < 0.01). CONCLUSION: Intense noise exposure may make the rat gastric ulcer worsened and induce negative effect on healing of it. The gastrointestinal endocrine would be disturbed by combined effect of intense noise exposure with gastric ulcer in rats.


Assuntos
Ruído , Peptídeos/sangue , Úlcera Gástrica/sangue , Animais , Masculino , Ratos , Ratos Wistar , Úlcera Gástrica/etiologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...