Solid Fluorescence Spectra Research Articles

A new indium-phenanthroline based complex as a fluorescence sensor: Synthesis, characterization and detection of multiple analytes

Chemical contaminants have posed a growing danger to environmental security and human health in recent years, causing considerable alarm. Herein, a new indium-based complex was synthesized by solvothermal method and using 1,10-phenanthroline (phen), namely, [(CH3)2NH2]+·[In(phen)Cl4]− (1). The crystal structure of the complex 1 was determined by single crystal X-ray diffraction (SCXRD). Moreover, elemental analysis (EA), Fourier transform infrared spectrum (FTIR), powder X-ray diffraction (PXRD) analysis and other structural characterization were carried out in detail. Thermal and solvent stabilities were investigated thoroughly. The liquid and solid fluorescence spectra had been also explored to discuss the influence of synthesis conditions on crystal configuration and the relationship between the complex and fluorescence properties. Moreover, complex 1 has good fluorescence properties and can be served as an outstanding candidate for the multi-response sensing of Fe3+, Cu2+, Ni2+, Co2+, Cr2O72− ions and nitrobenzene (NB). Furthermore, the limit of detection (LOD) and fluorescence quenching mechanism were studied in detail.

Preparation and Characterization of Phenanthroimidazole-based Derivatives with Ether Linkage at N1-Phenyl†

1,2-Diphenyl-1H-phenanthro[9,10-d]imidazole( PPI),as a model compound for PI-based compound in optoelectronic researches,exhibits good deep-blue emission with high color purity in solid,but has too bad thermal ability to apply as an emitter because its film would break under annealing. Based on the structure-property relationship of PI block,the newborn structure ONBPPI was prepared and confirmed by NMR spectra. It had the same substituted group at C2-position to PPI,and was introduced the ether linkage at N1-phenyl which was different to PPI at N1-position. The analysis of TGA and DSC showed that the thermal ability was enhanced accompany with the molecular weight increase from PPI to ONBPPI. AFM graphs showed that the film of ONBPPI had better stability than PPI in annealing at 90 ℃ for 2 h. And the similar fluorescence spectra in single molecular with fine split delivered that the unchanged transition process existed in both. In the film,a little blue-shift was observed in ONBPPI,which implied that the aggregation effect was weakened because of the ether bond insert. The phenomenon of the proportion of low-energy level emission increase in solid fluorescence spectra was found,but there was no obvious effect on deep-blue color. All of these results were consisted with our expected,and this strategy of enhancing multi-functions on PPI was realized under unchanged transition process by inserting ether linkage at N1-phenyl.

Construction and properties investigation of propeller type and three-fold interpenetration topology Mn(II) complexes

Two new complexes, namely [(Iptp)4(MnCl2)5·6DMF] (1) and [(Iptp)2(tpa)3·4DMF]n (2) have been synthesized by solvothermal method based on terpyridine ligand: 4′-(4-(1H-imidazol-1-yl)phenyl)-2,2′:6′,2″-terpyridine (Iptp) and auxiliary ligand p-phthalic acid (H2tpa), respectively. Single crystal X-ray diffraction analyses reveal that complex 1 is a propeller type pentanuclear zero dimensional structure. While complex 2 is a three-dimensional structure, and has a topological structure of three-fold interpenetrating networks. Thermogravimetric analysis indicate 1 and 2 have good thermal stability. Furthermore, solid fluorescence spectra properties of two complexes were also investigated, and the result shows the fluorescence intensity both of complex 1 and complex 2 are weaker than that of the Iptp ligand.

Molecular interactions of the inclusion complexes of hinokitiol and various cyclodextrins.

The aim of this study was to prepare inclusion complexes of hinokitiol (HT)/α-cyclodextrin (α-CD) and HT/β-cyclodextrin (β-CD) by cogrinding and to evaluate the differences in their formation. The physical properties of the preparation were evaluated by Job's plot, phase solubility studies, differential scanning calorimetry, powder X-ray diffraction, solid fluorescence spectra, and infrared absorption spectra. Intermolecular interaction in the solid state was confirmed to be in the ratios HT/α-CD=1/2 and HT/β-CD=1/1. Results indicated that the dissolution property of HT was improved by inclusion in the complexes HT/α-CD and HT/β-CD compared with HT crystals. The 1H-1H ROESY NMR spectrum of HT/α-CD showed that part of the seven-membered ring of HT and the isopropyl group of HT was linked to the wider edges of the two α-CDs. In HT/β-CD, the seven-membered ring of HT interacted with the narrower edge of β-CD and the isopropyl group of HT interacted with the wider edges. This structure of inclusion complexes was attributed to the difference in the cavity diameter of the CD and was thought to influence the dissolution properties.

Microwave-assisted solvent-free catalyzed synthesis and luminescence properties of 1,2,4,5-tetrasubstituted imidazoles bearing a 4-aminophenyl substituent

A solvent-free microwave-assisted four-component synthesis of 1,2,4,5-tetrasubstituted imidazoles bearing a 4-aminophenyl substituent was studied by condensation of p-phenylenediamine, aryl diketone, benzaldehyde derivatives and ammonium acetate in the presence of solid support silica gel and catalyst Keggin-H3[PW12O40]. The effects of four components molar ratio along with catalyst loading, irradiation time on the yields were investigated. Also, the structures of synthesized compounds were characterized by FT-IR, HRMS, 1H NMR and 13C NMR spectroscopy. Furthermore, their ultraviolet–visible maximum absorption, liquid fluorescence emission maximum and quantum yields were, respectively, measured in 0.05 M H2SO4 aqueous solution and in dichloromethane. Simultaneously, solid fluorescence spectra were determined in the powder state. The relationships between the optical behavior and the polarity of the solvents for some compounds were assessed. The results showed that the fluorescence quantum efficiency was increased by introducing amino phenyl in comparison with benzyl on 1-position of trisubstitued imidazoles. The compounds synthesized were sensitive to the polarity of the solvents.

Construction and optical properties of infinite Cd and finite Cu molecules stairs

Two coordination complexes, namely [(hpdq)(pta)Cd]n (1) and [(pptp)(pta)Cu2Cl] (2) have been synthesized by solvothermal method based on two polypyridyl ligands, 2,3,6,7,10,11-hexakis- (2-pyridyl)dipyrazino[2,3-f:2′,3′-h]quinoxaline) (hpdq), 4′-(4- (3H-pyrrol-3-yl)phenyl)- 2,2′:6′,2″- terpyridine (pptp) and auxiliary ligand p-phthalic acid (pta), respectively. Single crystal x-ray diffraction analyses reveal that complexes 1 and 2 assembled based on distinct asymmetric unit comprising one and two respective polypyridyl ligands but one Cd(II) and two Cu(I)ions, respectively. Among them, The asymmetric units in 1 was extended to one dimensional chain via the link of auxiliary ligand pta, just like infinite layers of stairs that connected by cadmium ions as the node. While that in 2 to Zero dimensional tetranuclear structure via the link of auxiliary ligand pta, just like finite four layers of stairs that Copper ion as the node connection. Furthermore, solid fluorescence spectra properties of two complexes were also investigated, and the result shows the fluorescence intensity of complex 1 is stronger than that of the hpdq ligand, but the fluorescence intensity of complex 2 is weaker than that of the pptp ligand. CCDC number of 1and 2 are 1483301 and 1483302.

Two new frameworks for biphenyl-3,3′,5,5′-tetracarboxylic acid and nitrogen-containing organics

AbstractTwo complexes, {Zn(bptc)0.5(bib)}n (I) and {Mn2(bptc)(pip)(H2O)}n (II) (H4bptc = biphenyl-3,3′,5,5′-tetracarboxylic acid; bib = 1,4-bis(2-methylimidazol-1-yl)butane; pip = 2-phenyl-1H-imidazo[4,5-f][1,10]phenanthroline) were synthesized and characterized by single-crystal X-ray diffraction, elemental analysis, IR, TGA and solid fluorescence spectra. The results show that I and II both have 3D network architectures. I has porous architecture with a 162 topology structure. Effective porosity calculated by Platon is 5.5 %. Moreover, it has a two-fold interpenetrating structure allowed by a 70.73° torsion between the benzene rings of the bptc4− ligand and the flexibility of bib. II has a tetranuclear structure composed of binuclear architecture units with the torsion of 43.44° between the benzene rings of the bptc4− ligand. TGA shows that the skeletons of I and II are stable up to 372°C and 553°C, respectively. I exhibits fluorescence.