Self-Healing Supramolecular Flexible Network of Zn(II): Exploring Chemo-Responsiveness, Antimicrobial Efficiency, and Variable Microelectronic Device Performances

The Zn(II)-supramolecular metallogel (i.e., Zn-Py) of 2,6-pyridinedicarboxylic acid was prepared through the addition of a metal source and 2,6-pyridinedicarboxylic acid as a low molecular weight gelator. The Zn-Py metallogel encapsulated N,N'-dimethylformamide as gel-immobilized polar aprotic solvent media. The mechanical features of the synthesized metallogel were investigated. The thixotropic behavior of the Zn-Py metallogel was also analyzed. The microscopic feature of the metallogel was imaged through FESEM and TEM studies. The EDS pattern of the metallogel ratified the role of different gel-building chemical constituents. The stimuli responsiveness of the metallogel was also tested. The metallogel-forming mechanistic protocol was visualized through FTIR and ESI mass spectroscopic analyses. The bioeffectiveness, i.e., antimicrobial potency, of Zn-Py was also studied. The antimicrobial efficiency against both Gram +ve and Gram -ve bacteria including Salmonella typhimurium (MTCC 98), Escherichia coli (MTCC 1667), Bacillus cereus (ATCC 13061), Listeria monocytogenes (MTCC 657), and Staphylococcus aureus (MTCC 96) was critically analyzed. The FESEM images of the live bacteria and damaged bacteria due to the action of the metallogel were experimentally investigated. The Zn-Py metallogel was also used to fabricate the heterojunction and Schottky-type photodetectors to show their excellent light-matter interaction and their potentiality as active material in optoelectronics. The electrical parameters of semiconductor diodes such as the p-n junction and Schottky diode fabricated by the synthesized Zn-Py metallogel were investigated. Outcomes of the experimental investigation demonstrated that the tested metallogel effectively showed p-n junction diode parameters, especially with the ideality factor (η) of 1.3 under a dark environment. This fabricated device efficiently depicted a great ON/OFF ratio of 33.4 at a reverse bias voltage of -2 V. The metal-semiconductor-metal (M-S-M) junction-type Schottky barrier diode was also fabricated using the Zn-Py metallogel where the Au/Zn-Py metallogel/Au-based device fabrication strategy was implemented.

Synthesis, spectral (FT-IR, 1H, 13C) studies, and crystal structure of [(2,6-CO2)2C5H3NSnBu2(H2O)]2·CHCl3

Di-n-butyltin(IV) 2,6-pyridinedicarboxylate [(2,6-CO2)2C5H3NSnBu2(H2O)]2·CHCl3, has been synthesized and characterized by elemental analyses, infrared and NMR (1H and 13C) spectroscopy, and single-crystal X-ray diffraction. The title complex crystallizes in the triclinic space group P 1 ‾ $P‾{1}$ ; with a = 9.2330(4), b = 10.4790(5), c = 20.2489(8) Å, α = 89.439(4), β = 87.492(3), γ = 85.888(4)°, V = 1951.96(15) Å3, and Z = 2. In this complex, the 2,6-pyridinedicarboxylate groups are tetradentate, chelating, and bridging ligands for the tin(IV) atoms. NMR spectra showed that the ligands bind to the tin(IV) center in the anionic (COO−) form. In the asymmetric unit of the dimeric complex, the monomer is composed of an n-Bu2Sn unit bonded to one 2,6-pyridinedicarboxylate group through one nitrogen and two oxygen donor atoms. It is also coordinated by a water molecule. In the dimer formed by carboxylate bridging, a trans-heptacoordinated geometry around the tin(IV) atom is established. The chloroform molecule is connected to the dimer by C–H···O contacts. Compound exhibits extended O–H···O and C–H···O hydrogen bonding networks leading to a supramolecular layer topology.

Sorption of methyl orange from aqueous solution by protonated amine modified hydrochar

The protonated amine modified hydrochar (PAMH) was synthesized by etherification, amination and protonated reaction with hydrochar, which was enriched with abundant protonated amine for methyl orange (MO) removal. PAMH was characterized by elemental analysis, scanning electron microscopy, nitrogen adsorption-desorption measurement, zeta potential and Fourier transform infrared. The sorption of MO from aqueous solution by PAMH was investigated by batch experiments. The results showed that sorption of MO was significantly influenced by the initial concentration of MO, temperature, contact time and ionic strength, while hardly affected by pH values ranging from 4 to 11. The pseudo-second-order and Langmuir equations were able to depict sorption kinetics and sorption isotherms, respectively. Thermodynamic analysis indicated that the sorption behavior was thermopositive and spontaneous. The maximum theoretical uptake computed by the Langmuir equation was 909.09 mg·g^-1 at 303 K, which suggested that PAMH was an effective sorbent to eliminate anionic dye from aqueous solution.

Mono- and bis-dipicolinic acid heterocyclic derivatives – thiosemicarbazides, triazoles, oxadiazoles and thiazolidinones as antifungal and antioxidant agents

A series of dipicolinic acid derivatives was synthesized and investigated for antimicrobial and antioxidant activity. Mono and bis derivatives of ethyl dipicolinate were utilized as starting materials for synthesis of mono- and bis-hydrazides. Thiosemicarbazides were obtained by reaction of hydrazides with isothiocyanates and cyclized into triazoles, thiadiazoles, oxadiazoles and thiazolidinones. Some of these products, especially those incorporating a thiazolidinone moiety in their structure, are excellent antioxidants, DPPH scavengers and antifungal agents.

Synthesis and characterization of complexes of a novel proton transfer salt and their inhibition studies on carbonic anhydrase isoenzymes

A novel proton transfer compound (HClABT)(+)(HDPC.H2DPC)(-) (1) and its Fe(III), Co(II), Ni(II) and two different Cu(II) complexes (2-6) have been prepared and characterized by spectroscopic techniques. Additionally, single crystal X-ray diffraction techniques were applied to all complexes. All compounds, including acetazolamide (AAZ) as the control compound, were also evaluated for their in vitro inhibition effects on human hCA I and hCA II for their hydratase and esterase activities. Although there is no inhibition for hydratase activities, all compounds have inhibited the esterase activities of hCA I and II. The comparison of the inhibition studies of 1-6 to parent compounds, ClABT and H2DPC, indicates that 1-6 have superior inhibitory effects. The inhibition effects of 2-6 are also compared to the inhibitory properties of the simple metal complexes of ClABT and H2DPC, revealing an improved transfection profile. Data have been analysed by using a one-way analysis of variance for multiple comparisons.

Synthesis and characterization of some metal complexes of a proton transfer salt, and their inhibition studies on carbonic anhydrase isozymes and the evaluation of the results by statistical analysis

A novel proton transfer compound (HMeOABT)(+) (HDPC)(-) (1) and its Fe(III), Co(II), Ni(II) and Cu(II) complexes (2-5) have been prepared and characterized by spectroscopic techniques. Complex 4 has distorted octahedral conformation revealed by single crystal X-ray diffraction method. Structures of the other complexes might be proposed as octahedral according to experimental data. All compounds were also evaluated for their in vitro inhibition effects on hCA I and II for their hydratase and esterase activities. Although there is no inhibition for hydratase activities, all compounds have inhibited the esterase activities of hCA I and II. Data have been analyzed by using a one-way analysis of variance. The comparison of the inhibition studies of 1-5 to parent compounds indicates that 1-5 have superior inhibitory effects. The inhibition effects of 2-5 are also compared to inhibitory properties of the metal complexes of MeOABT and H2DPC, revealing an improved transfection profile.