RESUMEN
A flexible polydentate Salamo-Salen-Salamo hybrid ligand H4L was designed and synthesized, which has rich pockets (salamo and salen pockets) so that it may have fascinating coordination patterns with transition metal(II) ions. Four multinuclear transition metal(II) complexes, novel butterfly-shaped homotetranuclear [Ni4(L)(µ1-OAc)2(µ1,3-OAc)2(H2O)0.5(CH3CH2OH)3.5]·4CH3CH2OH (1), helical homotrinuclear [Zn3(L)(µ1-OAc)2]·2CH3CH2OH (2), double-helical homotrinuclear [Cu2(H2L)2]·2CH3CN (3), and mononuclear [Ni(H2L)]·1.5CH3COCH3 (4), have been synthesized and characterized by single-crystal X-ray diffraction. The effects of different anions [OAc- and (O2C5H7)2-] on the complexation behavior of H4L with transition metal(II) ions were studied by UV-vis spectrophotometry. The fluorescent properties of the four complexes were studied with zebrafish, which are expected to be a potential light-emitting material. Ultimately, interaction region indicator (IRI) valuations, Hirshfeld surface analyses, density functional theory (DFT & TD-DFT), electrostatic potential analyses (ESP), and simulations were carried out to further demonstrate the weak interactions and electronic properties of the free ligand and its four complexes.
RESUMEN
A highly selective turn-on fluorescent and naked-eye colourimetric dual-channel probe for cyanide anions (CN-) has been designed and characterized. In the mixed solution (DMSO / H2O, 9:1, v / v), only CN- could cause an increase in the UV absorption intensity and the corresponding fluorescence intensity increased, and other anions had no significant effect on the probe. After treatment with cyanide in the probe solution, the solution showed a noticeable colour change, from light yellow to purple. Moreover, a fluorescence spectrophotometer can be used to observe that the fluorescence intensity of the solution is significantly enhanced. The response of the colourimetric and fluorescent dual-channel probe to CN- was attributed to nucleophilic addition, and the mechanism was determined by 1H NMR spectroscopy. In addition, this probe was used to detect CN- in actual water samples, including river water, drinking water, and tap water. The spiked CN- recovery rate is very high (97.2%-100.06%), and analytical precision is also very high (RSD < 2%), which shows its feasibility and reliability for detecting cyanide ions in actual water samples.
Asunto(s)
Colorimetría , Cianuros/análisis , Colorantes Fluorescentes/química , Contaminantes Químicos del Agua/análisis , Aniones/análisis , Colorantes Fluorescentes/síntesis química , Estructura Molecular , Espectrometría de FluorescenciaRESUMEN
Novel strategies still need to be proposed that can be used to identify and detect toxic environmental pollutants. In this paper, two channels of colorimetry and fluorescence 'turn-on' fluorescent probe 1 (7-hydroxy-8-[(2-hydroxy-phenylimino)- methyl]-4-methylbenzopyran-2-one) for the simple yet highly selective detection of CN¯ have been successfully designed and synthesized. Crystal features of probe 1 were defined using X-ray single crystal diffractometry. Probe 1 showed a strongly colorimetric and fluorescence response to CN¯ that induced obvious naked-eye colour changes in aqueous solution (DMSO/H2 O, 3:1 v:v). In addition, probe 1 for CN¯ detection displayed low detection limits of 3.91 × 10-8 M, which were significantly lower than the 1.9 × 10-6 M maximum level specified by the World Health Organization (WHO) for potable water. The sensing mechanism for probe 1 was attributed to the deprotonation process as shown by 1 H NMR titration. Moreover, based on the visible colorimetry and fluorescence change for probe 1 to CN¯, measurement was performed for simulated water samples containing CN¯. This study provides a broad prospect for solving other pollution problems and promoting the design of new fluorescent materials.
Asunto(s)
Cianuros , Bases de Schiff , Cumarinas , Colorantes Fluorescentes , Espectrometría de Fluorescencia , AguaRESUMEN
Diquat (DQ) is a typical bipyridine herbicide widely used to control weeds in fields and orchards. The severe toxicity of diquat poses a serious threat to the environment and human health. Metal-organic frameworks (MOFs) have received widespread attention due to their unique physical and chemical properties and applications in the detection of toxic and harmful substances. In this work, a two-dimensional (2D) Tb(III) functionalized MOF Tb(III)@1 (1 = [Cd(HTATB)(bimb)]n·H2O (Cd-MOF), H3TATB = 4,4',4â³-triazine-2,4,6-tribenzoicacid, bimb = 1,4-bis((1H-imidazol-1-yl)methyl)benzene) has been prepared and characterized. Tb(III)@1 has excellent optical properties and high water and chemical stability. After the Tb(III) is fixed by the uncoordinated -COO- in the 1 framework, Tb(III)@1 emits the typical green fluorescence of the lanthanide ion Tb(III) through the "antenna effect". It is worth noting that Tb(III)@1 can be used as a dual emission fluorescence chemical sensor for the ratio fluorescence detection of pesticide DQ, exhibiting a relatively low detection limit of 0.06 nM and a wide detection range of 0-50 nM. After the addition of DQ, a rapid color change of Tb(III)@1 fluorescence from green to blue was observed due to the combined effects of IFE, FRET and dynamic quenching. Therefore, a simple test paper box has been designed for direct on-site determination of pesticide DQ. In addition, the developed sensor has been successfully applied to the detection of DQ in real samples (fruits a Yin-Xia Sun and Bo-Tao Ji contributed equally to this work and should be considered co-first authors.nd vegetables) with satisfactory results. The results indicate that the probe developed in this study has broad application prospects in both real sample detection and actual on-site testing.
Asunto(s)
Diquat , Contaminación de Alimentos , Malus , Estructuras Metalorgánicas , Solanum tuberosum , Terbio , Zea mays , Estructuras Metalorgánicas/química , Zea mays/química , Malus/química , Contaminación de Alimentos/análisis , Diquat/química , Diquat/análisis , Terbio/química , Solanum tuberosum/química , Herbicidas/análisis , Herbicidas/química , Cadmio/análisis , Límite de DetecciónRESUMEN
A novel colorimetric-fluorescent dual-mode chemosensor (JT5) based on rhodamine B has been produced for monitoring Sn4+ in the DMSO/H2O (4:1, v/v) medium. It has high sensitivity, a low detection limit, a short response time (1â¯s) and high stability, and can still be maintained after two weeks with the red dual fluorescence/ colorimetric response. Enhancement of red fluorescence (591â¯nm) and red colorimetric (567â¯nm) response of JT5 by Sn4+ addition. The electrostatic potential of the sensor JT5 molecule was simulated to speculate on the sensing mechanism, and the IR, mass spectrometry and 1H NMR titration were utilized to further demonstrate that JT5 was coordinated to Sn4+ with a 1:1 type, the rhodamine spironolactam ring of JT5 opens up to form a penta-membered ring with Sn4+, meanwhile, its system may have chelation enhanced fluorescence (CHEF) effect. In addition, theoretical calculations were carried out to give the energy gaps of JT5 and [JT5â¯+â¯Sn4+] as well as to simulate the electronic properties of the maximal absorption peaks. Notably, the sensor JT5 was successfully applied to monitoring Sn4+ in zebrafish, and the JT5-loaded filter paper provided a solid-state platform for detecting Sn4+ by both naked eye and fluorescent methods. In summary, this work contributes to monitoring Sn4+ in organisms and solid-state materials and promotes understanding of Sn4+ functions in biological systems, environments, and solid-state materials.
Asunto(s)
Técnicas Biosensibles , Colorantes Fluorescentes , Rodaminas , Espectrometría de Fluorescencia , Pez Cebra , Rodaminas/química , Animales , Colorantes Fluorescentes/química , Técnicas Biosensibles/métodos , Agua/química , Colorimetría/métodos , Límite de DetecciónRESUMEN
The complete mol-ecule of the title compound, C(21)H(26)N(2)O(6), is generated by a crystallographic twofold axis and adopts a trans configuration with respect to the azomethine group. The two benzene rings are almost perpendicular to one another, making a dihedral angle of 89.53â (3)°. In the mol-ecular structure, pairs of intra-molecular O-Hâ¯N hydrogen bonds generate two six-membered rings. The crystal structure is further stabilized by inter-molecular C-Hâ¯O hydrogen bonds, which link four adjacent mol-ecules into a network structure.
RESUMEN
The title Schiff base bis-oxime compound, C(20)H(24)N(2)O(6), lies across an inversion centre and adopts an E configuration with respect to the C=N bond. In the mol-ecule, the oxime group is roughly coplanar with the benzene ring, forming a dihedral angle of 1.77â (2)°. An intra-molecular O-Hâ¯N hydrogen bond forms a six-membered ring with an S(6) motif. Weak inter-molecular C-Hâ¯O hydrogen bonding is present in the crystal structure.
RESUMEN
In the title complex, [Cu(C(14)H(14)NO(2))(2)], the discrete complex mol-ecules have crystallographic inversion symmetry. The slightly distorted square-planar coordination sphere of the Cu(II) atom comprises two phenolate O atoms and two oxime N atoms from two bidentate-chelate 2-[1-(eth-oxy-imino)-eth-yl]-1-naphtho-late O-ethyl oxime (L(-)) ligands [Cu-O = 1.8919â (17)â Å and Cu-N = 1.988â (2)â Å]. The two naphthalene ring systems in the mol-ecule are parallel, with a perpendicular inter-planar spacing of 1.473â (2)â Å, while each complex unit forms links to four other mol-ecules via inter-molecular methyl C-Hâ¯π inter-actions, giving an infinite cross-linked layered supra-molecular structure.
RESUMEN
The complete molecule of title compound, C(17)H(16)N(4)O(6), is generated by a crystallographic twofold axis. Within the mol-ecule, the two benzene units are approximately perpen-dicular, making a dihedral angle of 85.91â (4)°. In the crystal, mol-ecules are linked into a three-dimensional network by C-Hâ¯O hydrogen bonds and short Oâ¯O and Nâ¯O inter-actions, with distances of 2.998â (2) and 2.968â (3)â Å, respectively.
RESUMEN
In the title compound, C(15)H(13)N(3)O(3), the dihedral angle formed by the two benzene rings is 44.23â (2)°. The crystal structure is stabilized by aromatic π-π stacking inter-actions, with centroid-centroid distances of 3.825â (3) and 3.870â (4)â Å between the aniline and the nitro-benzene rings of neighbouring mol-ecules, respectively. In addition, the stacked mol-ecules exhibit inter-molecular C-Hâ¯N and C-Hâ¯O inter-actions.
RESUMEN
The mol-ecule of the title compound, C(27)H(26)N(2)O(4), lies across a crystallographic inversion centre and adopts an l-shaped configuration. Within the mol-ecule, the two naphthalene units are approximately perpendicular, making a dihedral angle of 80.24â (5)°. The two intramolecular O-Hâ¯N hydrogen bonds, generate S(6) ring motifs. In the crystal structure, every mol-ecule links five other mol-ecules into an infinite cross-linked layered supra-molecular structure via inter-molecular C-Hâ¯O hydrogen bonds, C-Hâ¯π inter-actions and π-π stacking inter-actions [centroid-centroid distance = 3.956â (4)â Å].
RESUMEN
The title compound, C(28)H(28)N(2)O(4), was synthesized by the reaction of 2-acetyl-1-naphthol with 1,4-bis-(amino-oxy)butane in ethanol. The molecule, which lies about an inversion centre, adopts a linear structure, in which the oxime groups and naphthalene ring systems assume an anti conformation. The intra-molecular inter-planar distance between parallel naphthalene rings is 1.054â (3)â Å. Intra-molecular O-Hâ¯N hydrogen bonds are formed between the oxime nitro-gen and hydr-oxy groups.
RESUMEN
In the title complex, [Cu(C(12)H(7)Cl(2)N(2)O)(2)], the Cu(II) center is tetra-coordinated by two phenolic O and two azomethine N atoms from two bidentate 4-chloro-2-[(2-chloro-3-pyrid-yl)imino-meth-yl]phenolate (L) ligands. In the crystal structure, the Cu(II) atom has a distorted square-planar coordination environment. The dihedral angles between the benzene and pyridyl rings are 54.39â (3) and 80.14â (4)°, indicating that the pyridine ring has a considerably weaker steric hindrance. The packing of the mol-ecule is controlled by C-Hâ¯π(Ph) inter-actions and short Oâ¯Cl inter-actions [3.196â (4)â Å], linking the mol-ecules into a chain-like structure along the c axis.
RESUMEN
The mol-ecule of the title compound, C(21)H(26)N(2)O(6), which lies across a crystallographic inversion centre, crystallizes with two unique half-molecules in the symmetric unit and adopts a linear configuration and the imino group is coplanar with the aromatic ring, making a dihedral angle of 3.26â (3)°. Strong intra-molecular O-Hâ¯N and weak inter-molecular O-Hâ¯O and C-Hâ¯O hydrogen bonds and weak inter-molecular π-π stacking inter-actions [centroid-centroid distance = 4.419â (2)â Å]establish an infinite three-dimensional supra-molecular structure.
RESUMEN
The mol-ecule of the title compound, C(31)H(34)N(2)O(4), adopts an L-shaped configuration, in which the naphthalene units are approximately perpendicular, making a dihedral angle of 87.89â (3)°. Intramolecular H-bonds are formed between the OH substituents and the N atoms at each end of the molecule. In the crystal structure, each mol-ecule links six other mol-ecules into an infinite three-dimensional network supra-molecular structure, which is built from one-dimensional zigzag chains via weak C-Hâ¯π stacking and inter-molecular C-Hâ¯O hydrogen bonds.
RESUMEN
The Schiff base, C(18)H(20)N(2)O(2), which lies about an inversion centre, adopts a linear conformation. The mol-ecules are packed by C-Hâ¯π inter-actions, forming a two-dimensional supra-molecular network.
RESUMEN
The title compound, C(29)H(30)N(2)O(4), adopts a distorted Z configuration with respect to the oxime group, which is almost coplanar with the adjacent naphthalene ring [dihedral angle = 4.11â (2)°]. There is one half-mol-ecule in the asymmetric unit, with a crystallographic twofold rotation axis passing through the central C atom of the -CH=N-O-(CH)(5)-O-N=CH- bridge. Within the mol-ecule, the dihedral angle formed by the two naphthalene rings is 79.08â (3)°, and there are two intra-molecular O-Hâ¯N hydrogen bonds.
RESUMEN
A new naphthalenediol-based bis(salamo)-type fluorescent probe H4L for Zn2+ and CN- was reported. Probe H4L showed a highly selective fluorescence enhancement toward Zn2+ over other metal ions including Cd2+, and obtained the L-Zn2+complex can only detect CN- in various anions. Their recognition mechanisms were explained by Job plots, fluorescent and UV-vis titrations, and theoretical calculations. The L-Zn2+complex has been synthesized and structurally characterized using Hirshfeld surface analysis, elemental analyses, IR, UV-Vis and fluorescent spectra. Additionally, the relay probe with the wide adaptability of pH range and excellent stability showed highly selectivity for CN- recognition.
RESUMEN
Four new hetero-pentanuclear 3d-4f complexes [Zn4(L)2La(NO3)2(OEt)(H2O)] (1), [Zn4(L)2Ce(NO3)2(OMe)(MeOH)] (2), [Zn4(L)2Pr(NO3)2(OEt)(EtOH)] (3) and [Zn4(L)2Nd(NO3)2(OMe)(MeOH)] (4) were synthesized by the reactions of a newly synthesized octadentate bis(salamo)-based tetraoxime ligand (H4L) with Zn(OAc)2·2H2O and Ln(NO3)3·6H2O (Ln = La, Ce, Pr and Nd), respectively, and characterized via elemental analyses, FT-IR, UV-Vis spectroscopy and single crystal X-ray crystallography. The X-ray crystallographic investigation revealed that all ZnII ions were located in N2O3 coordination spheres, and possessed a trigonal bipyramid coordination environment. The LnIII ion lay in an O8 coordination sphere, and adopted a distorted square antiprismatic coordination environment. Furthermore, supramolecular interactions and fluorescence properties were investigated.
RESUMEN
The mol-ecule of the centrosymmetric title compound, C(18)H(20)N(2)O(6), assumes an E configuration with respect to the azomethine C=N bond. The imino group is coplanar with the aromatic ring. Intra-molecular O-Hâ¯O and O-Hâ¯N bonds are found between the hydroxyl groups and adjacent O (or N) atoms. In the crystal structure, inter-molecular O-Hâ¯O bonds link each mol-ecule to two others, forming a layered network.