An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Abstract Two novel lanthanide coordination polymers, {[Ln(stp)(bipy)(H 2 O)] · (H 2 O)} n [Ln = Eu ( 1 ) and Dy ( 2 )], were synthesized by hydrothermal reactions of 2‐sulfoterephthalate (stp) and 4,4′‐bipyridine (bipy) ligands with europium/dysprosium(III) salts. Structural analyses show that both complexes 1 and 2 are isomorphic and crystallize in the monoclinic crystal system with space group P 2 1 / n . Complex 1 exhibits a two‐dimensional grid‐like structure from europium(III) ions bridged by the carboxyl and sulfonate groups of stp ligands. Notably, the stretching 4,4′‐bipyridine ligands besides the 2D grid‐like layers form π ··· π interactions and interpenetrate into the empty voids of another adjacent layer into a twofold interpenetrated structure. Fluorescence analysis show that the emission of two complexes exhibit the characteristic peaks of lanthanide ions.
Abstract A new Cd(II) coordination polymer, [Cd(CNA)] n ( 1 ) (H 2 CNA = 3-(carboxymethoxy)-2-naphthoic acid), was hydrothermally synthesized and structurally characterized by single-crystal X-ray diffraction. The crystals are monoclinic, space group P 2 1 / c with a = 16.9698(18), b = 7.8314(8), c = 8.9553(10) Å, β = 100.657(2)°, V = 1169.6(2) Å 3 , Z = 4, D calcd. = 2.03 g cm −3 , μ (Mo K α ) = 1.9 mm −1 , F (000) = 696 e, R = 0.0305, wR = 0.0784 for 172 refined parameters and 2285 data. Each CNA anion bridges three Cd(II) cations to give rise to a two-dimensional network structure. Topologically, if each CNA anion is regarded as a linker, and each Cd(II) atom considered as a 4-conencted node, the structure is simplified as a 4-connected (4,4) network. The solid state photoluminescent properties of the compound were also studied at room temperature.
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
The photoluminescence (PL) mechanism of graphene quantum dots (GQDs) has remained ambiguous, which restricts their simulations and applications. Here, stable and pure GQDs were fabricated by laser ablation of highly oriented pyrolytic graphite along the orientation parallel to the graphite layers. Two intense PL peaks were surprisingly achieved, which experimentally demonstrates that the double emissions coexist in the PL mechanism. This finding contrasts with the conventionally reported cases in which only one PL peak was observed and intensively studied. The peak at shorter wavelengths corresponds to the reported PL peak. This peak is redshifted with excitation wavelengths and is attributed to transitions from π* to π states rather than from π* to surface states as in most conventionally assigned situations. Notably, the peak at longer wavelengths is derived from the emission transition from π* to surface states and exhibits an excitation wavelength-independent feature. Because of the sufficient passivation and the resulting increase in electron density on the GQDs, the bandwidth that is composed of the energy levels of all surface states becomes narrowed and close to that of a single GQD, which causes the peak position to be insensitive to the sizes of the GQDs. Furthermore, an investigation indicates that in quite a few reported PL spectra, with an intense peak, a weak shoulder at longer wavelengths appeared with excitation wavelength-independence although this shoulder was usually ignored. This work is significant not only for true understanding of the PL mechanism but also for multi-colour photoluminescence and cancer cell imaging applications.
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Abstract In this work, a highly sensitive and selective method for detecting folic acid (FA) was developed using D‐penicillamine (DPA) stabilized Ag/Cu alloy nanoclusters (DPA@Ag/Cu NCs). The yellow emission of DPA@Ag/Cu NCs was found to be quenched upon the addition of FA to the system. The fluorescence intensity quenching value demonstrated a linear relationship with FA concentrations ranging from 0.01 to 1200 μM, with a limit of detection (LOD) of 5.3 nM. Furthermore, the detection mechanism was investigated through various characterization analyses, including high resolution transmission electron microscopy, fluorescence spectra, ultraviolet‐visible absorption spectra, and fluorescence lifetime. The results indicated that the fluorescence quenching induced by FA was a result of electron transfer from FA to the ligands of DPA@Ag/Cu NCs. The selectivity of the FA sensor was also evaluated, showing that common amino acids and inorganic ions had minimal impact on the detection of FA. Moreover, the standard addition method was successfully applied to detect FA in human serum, chewable tablets and FA tablets with promising results. The use of DPA@Ag/Cu NCs demonstrates significant potential for detecting FA in complex biological samples.
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