Chemistry Journal of Moldova

 

Graphycal Abstract: In this work, the synthesis of Schiff bases derived from trans-(R,R)-diaminocyclohexane by microwave irradiation (MW) is presented. The reaction yields varied between 31% and 69%, being influenced by the electronic nature of the substituents (H, Cl, Br, NO₂, MeO, t-BuO, BnO, and 4-(4-Me)PhO) and the reaction temperature. The spectrophotometric properties of the products were investigated by UV-Vis spectrophotometry, revealing bathochromic and hypso-chromic effects attributable to the different substituent groups. These effects were interpreted by DFT calculations with the B₃LYP functional at the 6-311G(d,p) level. The results suggest that the electronic properties of the substituents in the para position have a significant impact on the spectroscopic characteristics of the Schiff bases.

 

Graphycal Abstract: Lipid fractions from Helianthus annuus L. pollen collected across three Moldovan agroclimatic zones were analyzed via GC-MS after Soxhlet extraction, saponification, and methylation. Chromatographic profiling resolved >40 constituents, including: Polyunsaturated fatty acid esters (e.g., methyl linolenate, a ω-3 precursor); Diterpenoid derivatives (methyl labdatrien-19-oate); Oxygenated sterols (lanostan-3-one); Lipophilic vitamins (α-tocopherol, retinol derivatives). Chemometric analysis revealed climate-induced shifts in metabolite profiles, with heat and drought favoring terpenoid accumulation. Results highlight sunflower pollen as a structurally rich source of bioactive lipids with nutraceutical potential.

 

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Graphycal Abstract: The synthesis of three structurally distinct copper(II) coordination compounds with iminodiacetic acid (H₂IDA) as ligand was achieved by varying the reaction pH. Under neutral conditions (pH 6–6.5), compound 1 formed as a two-dimensional ionic coordination polymer, {[NH₂(CH₃)₂]₂[Cu₃(IDA)₄]·1.75H₂O}ₙ, consisting of layered [Cu₃(IDA)₄]²ₙ⁻ anions stabilized by hydrogen-bonding networks. Under basic conditions (pH 8–8.5), compound 2 was obtained as a neutral 2D molecular polymer, {[Cu₃(IDA)₂(IDAH)₂]·5H₂O}ₙ, built from trinuclear copper units bridged by bi- and monodeprotonated ligands. Under acidic conditions (pH 3), compound 3, ((CH₃)₂OH)₂[Cu(IDA)₂]·[Cu(IDAH)₂], was isolated as an ionic structure containing neutral and anionic mononuclear complexes charge-balanced by protonated dimethylether cations.

 

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Graphycal Abstract: The contribution of in silico analysis in the development of corrosion inhibitors field by predicting adequate new molecules that could be employed for this purpose. QSAR analysis of already published experimental results of corrosion inhibition efficiency (IE%) of mild steel in acidic media for eighteen furan derivatives was performed.

 

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Graphycal Abstract: Melissa officinalis L. and Urtica dioica L. were evaluated for their phytochemical composition and antioxidant and anti-lithiatic activities. LC-MS/MS analysis showed that M. officinalis contained a more diverse profile, especially flavonoids and phenolic acids enriched in the ethyl acetate fraction, while U. dioica demonstrated a simpler composition dominated by myricetin, riboflavin, sinapic acid, catechin, and β-carotene in its aqueous fraction. M. officinalis ethyl acetate extract showed the strongest antioxidant capacity in DPPH, ABTS, and FRAP assays. Its aqueous extract also exhibited notable anti-lithiatic activity, inhibiting calcium oxalate crystal formation by 87.12% at 2 mg/mL.

 

 

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Graphycal Abstract: Concentrations of fluoride ions in the Dniester river and Dubasari reservoir, located on the territory of the Republic of Moldova, were analysed for 2011–2024. They ranged 0.05–1.07 mg/L, with higher values during low-water periods. Despite seasonal sampling, no clear dynamics were observed, due to altered hydrological regime. Fluoride levels were lower than the World Health Organization for drinking water.