Electronic structure and photoelectron spectra of nickel (II) acetylacetonate and its thio- and amino-substituted analogues

Fluorimetric determination of aqueous formaldehyde employing heating and ultrasound-assisted approach through its derivatization with a ß-diketone-nickel(2+) complex immobilized in a PMMA flow cell

Formaldehyde (FA) is a highly toxic substance present in many matrices, including freshwater as well as found in natural mechanisms such as rainfall and combustion of organic matter. Consumption of water contaminated with high levels of FA can cause severe short-term or long-term health problems. Due to these health risks, procedures are necessary to determine and quantify FA in aqua sources This paper reports on a study of fluorimetric determination of FA using a nickel(2 + )-diketonate coordination compound immobilized as a solid precursor. The compound was characterized by electronic absorption, Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), thermogravimetry (TG), optical microscopy (OM), and scanner electron microscopy (SEM). The methodology was based on the reaction of the synthesized compound with an ammoniacal buffer generating a selective reagent for formaldehyde: fluoral-P. The product of the reaction generates 3,5-diacetyl-1,4-dihydrolutidine (DDL), which is responsible for the fluorescence of the system. Several parameters such as temperature, duration of heating time, and dilution effect with the best effects were studied to carry out FA determination. Under the optimum experimental conditions, a linear response ranging from 1.0 to 10.0 mg/L FA (R = 0.997 and n = 10), and a detection (3σ criterion) and quantification (10 σ criterion) limit estimated at 0.129 and 0.389 mg/L, respectively were achieved. The FA analysis was able to be conducted in 05 min with a relative standard deviation estimated at 1.10 %.

Synthesis of a non-hazardous/smart anti-corrosion nano-carrier based on beta-cyclodextrin-zinc acetylacetonate inclusion complex decorated graphene oxide (β-CD-ZnA-MGO)

Recently, the high research considerations have been devoted to designing smart coatings with self-healing propensity along with improved anti-corrosion properties, durability, and effectiveness. In the present work, a novel nano-container, namely beta-cyclodextrin (β-CD), was introduced and applied for encapsulating and subsequent controlled release of a metal-organic inhibitor, namely zinc acetylacetonate (ZnA) in the polymeric matrix. The smart release is another principal object which has been lacked in recent reports. For this aim, graphene oxide nanoparticles were employed to carry the inclusion complexes (β-CD-ZnA) to the defected zones of coatings. FT-IR, Raman, XRD, and UV-vis experiments ascertained that the β-CD-ZnA inclusion complex successfully adsorbed onto the GO sheets modified by 3-aminopropyl tri-ethoxysilane (MGO). The electrochemical inspections (i.e., potentiodynamic polarization and EIS) proved that the β-CD-ZnA-MGO particles could remarkably inhibit the steel corrosion in 3.5 % NaCl solution via mixed cathodic/anodic retardation mechanisms with approximately 93 % efficiency after 48 h metal exposure. It was also found that the corrosion protection performance of the polymeric matrix loaded by β-CD-ZnA-MGO nano-particles enhanced markedly, assigning to the significant epoxy defect coverage by β-CD-ZnA. The intelligent transmission was affirmed by EDS-mapping analysis in the defected regions of epoxy coating. The high quantity of the Zn element ensured the successful adsorption of the ZnA on the metal surface. The damage, as well as the delaminated degrees of the un-scratched epoxy coating, was estimated by the EIS experiment outcomes. Achievements reflected that the presence of β-CD-ZnA-MGO nano-filler in the epoxy resin matrix significantly reduced the electrolyte/ion diffusion. Furthermore, the computational results elucidated from DFT-D approach clarified the stronger β-CD-ZnA affinity towards the GO adsorbent compared with the pure β-CD, supporting the experimental findings.