Mixed-ligand Cd Research Articles

Water-stable mixed-ligand Cd(II) metal-organic frameworks as bis-color excited fluorescent sensors for the detection of vitamins and pesticides in aqueous solutions

The synthesis and characterization of three 2D to 3D metal-organic frameworks (MOFs) with mixed ligands, namely {[Cd(DINT)(TPA)(H2O)]ACN}n (BAO24) (H2TPA = terephthalic acid, DINT = 1,4-di(imidazol-1-yl)naphthalene, and ACN = acetonitrile), {[Cd(DINT)(IPA)]DMF}n (BAO25) (H2IPA = isophthalic acid and DMF = N,N-dimethylformamide), and [Cd(DINT)(PA)]n (BAO26) (H2PA = phthalic acid), were reported herein. The structures and purities of the MOFs were revealed and confirmed by single-crystal X-Ray diffraction, Fourier transform infrared spectroscopy, powder X-Ray diffraction, thermogravimetric analysis, and elemental analysis. The MOFs exhibited a fluorescence emission peak around λem = 340 nm with relative excitation wavelengths at both 230 and 290 nm. Since the MOFs showed similar fluorescence properties, BAO24 was selected as a representative MOF in the fluorescent sensing processes. The result showed that BAO24 exhibited a high sensitivity for vitamin B2. However, when sensing pesticides, the sensor performed differently at each excitation wavelength. At λex = 230 nm, the sensor was quenched the most significantly with the nitenpyram analyte, while at λex = 290 nm, the highest fluorescence quenching was achieved by the imidacloprid analyte.

Statement of Retraction: Two mixed-ligand Cd(II)-coordination polymers: structural diversity and antitumor activity against human osteogenic sarcoma cells

Statement of Retraction: Two mixed-ligand Cd(II)-coordination polymers: structural diversity and antitumor activity against human osteogenic sarcoma cells

Mixed ligand Cd(II) coordination architectures based on bulky anthracene-9-carboxylate ligand: Crystal structures and optical properties

The reaction of cadmium nitrate with anthracene-9-carboxylic acid (HL) and two terpyridine derivatives, 4′-phenyl-2,2′:6′,2″-terpyridine (L1) and 4′-(4-pyridyl)-2,2′:6′,2″-terpyridine (L2), led to the formation of two mixed-ligand coordination compounds, [Cd(C21H15N3)(C15H9O2)2] (1) and [Cd2(C20H14N4)2.5(C15H9O2)4]n (2). Coordination compounds were characterized by single-crystal X-ray diffraction, elemental analysis, FT-IR, UV–Vis and luminescence spectroscopy. X-ray analysis of prepared coordination compounds reveals that 1 is single nuclear coordination complex, whereas 2 is a one-dimension coordination polymer with zigzag chain structure. The nature of L1 and L2 ligands has an essential influence on the molecular geometry and assembly, as well as on the physicochemical properties of complexes 1 and 2. Finally, 1D polymer 2 was utilized as a precursor for the fabrication of an organic light-emitting diode (OLED@2) whose emission wavelengths were investigated at different voltage.

Antimicrobial and antioxidant studies of Schiff base, 2-(2-hydroxy-2-methyl-1-phenylpropylidene) hydrazine carbothioamide and its mixed ligand cd (II) complexes

New mononuclear mixed ligand Cadmium(II) complexes of the type [Cd(L)(diimine)] (1,2) [where L = 2-(2-hydroxy-2-methyl-1-phenylpropylidene)hydrazinecarbothioamide; diimine = 2,2’-bipyridine (1), 1,10-phenanthroline (2)] have been synthesized and characterized by spectroscopic techniques such as FT-IR, UV-Visible, and1H and 13CNMR Spectroscopy. From the investigations of spectral data, it is evident that the heterocyclic bases (2,2’-bipyridine and 1,10-Phenanthroline) act as neutral bidentate ligand coordinating to the metal ion through two nitrogen donor atoms addition to azomethane nitrogen, thiolate Sulphur, and hydroxyl oxygen in the Schiff base ligand. The synthesized Schiff base metal chelates have been screened for their anti-microbial activities using the agar well diffusion method against different selected types of bacteria and fungi in addition to antioxidant activity. The prepared Schiff base ligand and its metal complexes exhibited good antimicrobial and antioxidant activities. The antibacterial and antifungal efficacy of Complex-1 was higher than that of all the prepared compounds. In the case of antioxidant activity, Complex-2 has stronger scavenging activity among them. Keywords: Cd (II) metal complexes, 2,2’-Bipyridine, 1,10-Phenanthroline, Antimicrobial activities.

A Novel Cd(II) Isophthalate Complex with Triethanolamine: Crystal Structure, Fluorescence and Antimicrobial Activity

A mixed ligand Cd(II) complex [Cd(IsoPht)(TEA)H2O]·3H2O was synthesized for the first time by using isophthalic acid (H2IsoPht) and tetradentate triethanolamine (TEA) and characterized by X-ray single-crystal diffraction, FT-IR, and thermogravimetric analysis (TGA). This novel complex crystallizes in the triclinic system with P-1 space group and distorted monocapped trigonal prismatic geometry. The Cd(II) has seven coordinates with bidentate Isopht, a TEA in the tetradentate mode, and an aqua ligand. The fluorescence properties of the Cd(II) complex and TEA ligand were investigated at room temperature. The present Cd(II) complex was also tested for its antimicrobial activity by in vitro agar diffusion method against some Gram-positive and Gram-negative bacteria and a fungus.

Devising Mixed-Ligand Based Robust Cd(II)-Framework From Bi-Functional Ligand for Fast Responsive Luminescent Detection of Fe3+ and Cr(VI) Oxo-Anions in Water With High Selectivity and Recyclability.

Environmental issue related applications have globally surfaced as hottest areas of research, wherein luminescent metal-organic frameworks (LMOFs) with functionalized pores put unique signature in real-time monitoring of multiple classes of toxic compounds, and overcome many of the challenges of conventional materials. We report a two-fold interpenetrated, mixed-ligand Cd(II)-organic framework (CSMCRI-11) [Cd1.5(L)2(bpy)(NO3)]·DMF·2H2O (CSMCRI = Central Salt and Marine Chemical Research Institute, HL = 4- (1H-imidazol-1-yl)benzoic acid, bpy = 4,4′-bipyridine) that exemplifies bipillar-layer structure with two different Cd(II) nodes, and displays notable robustness in diverse organic solvents and water. Intense luminescence signature of the activated MOF (11a) is harnessed in extremely selective and fast responsive sensing of Fe3+ ions in aqueous phase with notable quenching constant (1.91 × 104 M−1) and impressive 166 ppb limit of detection (LOD). The framework further serves as a highly discriminative and quick responsive scaffold for turn-off detection of two noxious oxo-anions (Cr2O7 2− and CrO4 2−) in water, where individual quenching constants (CrO4 2−: 1.46 × 104 M−1; Cr2O7 2−: 2.18 × 104 M−1) and LOD values (CrO4 2−: 179 ppb; Cr2O7 2−: 114 ppb) rank among best sensory MOFs for aqueous phase detection of Cr(VI) species. It is imperative to stress the outstanding reusability of the MOF towards detection of all these aqueous pollutants, besides their vivid monitoring by colorimetric changes under UV-light. Mechanism of selective quenching is comprehensively investigated in light of absorption of the excitation/emission energy of the host framework by individual studied analyte.

Effect of structural features on the stability and bactericidal potential of two cadmium coordination polymers

Two mixed ligand Cd(ii) coordination polymers have been synthesized using three methods byin situdecarboxylation of phenylmalonic acid. CPs were screened for their antibacterial activities and the influence of structural properties was studied.

Two mixed-ligand Cd(II)-coordination polymers: structural diversity and antitumor activity against human osteogenic sarcoma cells

A systematic investigation into the reactions of Cd(NO3)2·4H2O with o- and p-phenylenediacetic acid within the presence of the semi-rigid 1,4-bis(imidazol-1-ylmethyl)benzene (bimb) co-ligands under similar conditions was carried out. In this study, two novel coordination polymers containing Cd(II) ions as the metal ions {[Cd(μ-opda)(bimb)]·DMF}n (1, opda = 1,2-phenylenediacetate) and [Cd(μ-ppda)(bimb)0.5]n (2, ppda = 1,4-phenylenediacetate) have been prepared and structurally characterized. Furthermore, the inhibitory function of these two synthetic complexes on MG-63 human osteogenic sarcoma cells was evaluated with cell counting kit-8. And the Annexin V-FITC/PI apoptosis detection was performed to detect the induction ability of the complexes on the cancer cell apoptosis. Then, the western blot was performed to measure the activation level of the PTEN-AKT pathway.

Pore-Functionalized and Hydrolytically Robust Cd(II)-Metal-Organic Framework for Highly Selective, Multicyclic CO2 Adsorption and Fast-Responsive Luminescent Monitoring of Fe(III) and Cr(VI) Ions with Notable Sensitivity and Reusability.

Metal-organic frameworks (MOFs) show a distinctive pre-eminence over other heterogeneous systems for adsorption of carbon dioxide (CO2) gas and fluorescence detection of water contaminating ions, where integration of both these attributes along with enhancement of pore functionality and water stability is crucial for potential applications related to environmental remediation. Pore functionalization has been achieved in a 2-fold interpenetrated, mixed-ligand Cd(II)-framework [Cd1.5(L)2(bpy)(NO3)]·2DMF·2H2O (CSMCRI-5) (HL = 4-(4-carboxyphenyl)-1,2,4-triazole, bpy = 4,4'-bipyridine, DMF = dimethylformamide, CSMCRI = Central Salt & Marine Chemicals Research Institute) by utilizing a bifunctional ligand HL. The bpy-pillared framework, containing diverse Cd(II) nodes, optimum sized voids, and free N-atom affixed one-dimensional porous channels, shows notable structural robustness in diverse organic solvents and water. In spite of a negligible surface area, the activated MOF (5a) exhibits good CO2 uptake and highly selective CO2 adsorption over N2 (259.94) and CH4 (14.34) alongside minor loss during multiple CO2 adsorption-desorption cycles. Luminescence studies demonstrate extremely selective and ultrafast sensing of Fe3+ ions in the aqueous phase with notable quenching (1.13 × 104 M-1) as well as an impressive 98 ppb limit of detection (LOD). Importantly, Fe3+ detection is exclusively retained under simulated physiological conditions. The framework further serves as a quick-responsive scaffold for toxic CrO42- and Cr2O72- anions, where individual quenching constants (CrO42-: 1.73 × 104 M-1; Cr2O72-: 5.42 × 104 M-1) and LOD values (CrO42-: 280 ppb; Cr2O72-: 320 ppb) rank among the best sensory MOFs for aqueous phase detection of Cr(VI) species. It is imperative to stress vivid monitoring of all these aqueous pollutants by a handy paper-strip method, besides outstanding applicability of 5a toward their recyclable detection. Mechanism of selective quenching is comprehensively investigated in light of the absorption of the excitation/emission energy of the host framework by an individual studied analyte.

Tunable excitation-dependent emissions in mixed-ligand Cd(II) complexes

Two Cd(II) coordination compounds, i.e. [Cd(HL)(phen)2(H2O)]·HL·3H2O (1) and {[Cd(HMeL)2(4,4′-bipy)(H2O)]·H2O}n (2) and (where HL = N-carboxymethyl-N-phenyliminoacetato, HMeL = N-carboxymethyl-N-(m-methylphenyl)iminoacetato, 4,4′-bipy = 4,4′-bipyridine and phen = phenanthroline) have been synthesized and characterized by elemental analysis, IR and single-crystal X-ray diffraction methods. The photoluminescence properties and mechanisms, studied by means of solid state absorption, excitation/emission spectra, time-resolved lifetime techniques, and density functional theory (DFT) calculations, indicate that the emissions of both compounds originate from a combination of exciplex and charge-transfer complex. Interestingly, both compounds exhibit excitation-dependent emissions, which can be used to fine-tune their emission wavelengths.

Two mixed-ligand Cd(ii)–organic frameworks with unique topologies: selective luminescence sensing of TNP and Cu2+ ions with recyclable performances

Two luminescent Cd(ii)–organic frameworks exhibit unprecedented (4,4,5,5)-c and (4,4,4,6,7)-c topologies, and highly sensitive and selective sensing of 2,4,6-trinitrophenol and Cu2+.

Syntheses and Characterization of Cadmium (II) Oxide Nanostructure from two Nano-sized Cadmium (II) Coordination Polymers

Two nano-sized mixed-ligand Cd (II) coordination polymers; [Cd (4,4' -bpy) (C4H4O4)].1/4 H2O (1) and[Cd(bpy)1.5 (NO3)2].3H2O (2) (bpy=bipiridine) were synthesized by a sonochemical method and characterized by elemental analyses, thermal gravimetric analysis (TGA), differential thermal analysis (DTA), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR). The crystallinity of these compounds were studied by Powder X-ray diffraction (XRD). CdO nanostructures were obtained by direct calcinations of nano polymers at 400 oC. The cadmium (II) oxidenano-particles were characterized by Powder X-ray diffraction (XRD) and scanning electron microscopy (SEM).

Ultrasound assisted syntheses of a nano-structured two-dimensional mixed-ligand cadmium(II) coordination polymer and direct thermolyses for the preparation of cadmium(II) oxide nanoparticles

A nano-sized mixed-ligand Cd(II) coordination polymer, {[Cd(bpa)(4,4′-bipy) 2(H 2O) 2](ClO 4) 2} n ( 1); bpa = trans-1,2-bis(4-pyridyl)ethane and 4,4′-bipy = 4,4′-bipyridine, has been synthesized by a sonochemical method and characterized by IR and 1H NMR spectroscopy. Compound 1 grows in one dimension by two different bridging ligands, 4,4′-bipy and bpa. The thermal stability of compound 1 in the bulk form and nano-sized was studied by thermogravimetric (TG) and differential thermal analysis (DTA). The crystallinity of this compound was studied by X-ray powder diffraction and compared with an XRD simulation of the single crystal data. CdO nanoparticles were obtained by direct calcination at 500 °C and decomposition in oleic acid at 200 °C of the nano-sized compound 1. The obtained cadmium(II) oxide nano-particles were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM).