Synthesis of pyrimidine Schiff base transition metal complexes: characterization, spectral and electrochemical analyses, and photoluminescence properties

Zengin, Gulay/0000-0001-5454-006XWOS: 000441789200035This study includes the synthesis, characterization, electrochemical analysis and photoluminescence properties of a Schiff base ligand bearing a pyrimidine ring and its Co(II), Ni(II), Cu(II) and Pd(II) metal complexes. The Schiff base ligand was derived from the condensation reaction of a pyrimidine amine with 2-hydroxy-1-naphthaldehyde. The structures were characterized using FT-IR, UV-Vis, elemental analysis, magnetic susceptibility and electrolytic conductivity. The ligand and its metal complexes displayed strong violet emissions upon UV exposure. The photoluminescence quantum yield and excited-state decay were measured for the ligand and its complexes. The excited-state lifetime for the ligand was 3.70 ns and its quantum yield of luminescence was found to be 0.40. A reduction in photoluminescence intensity and quantum yield was observed upon metal ion complexation. The compounds synthesized were studied by cyclic voltammetry to probe the existence of electrochemical reduction and oxidation processes

Subclinical hypothyroidism in childhood — current knowledge and open issues

Subclinical hypothyroidism is defined as serum levels of TSH above the upper limit of the reference range, in the presence of normal concentrations of total T4 or free T4. This biochemical profile might be an indication of mild hypothyroidism, with a potential increased risk of metabolic abnormalities and cardiovascular disease recorded among adults. Whether subclinical hypothyroidism results in adverse health outcomes among children is a matter of debate and so management of this condition remains challenging. Mild forms of untreated subclinical hypothyroidism do not seem to be associated with impairments in growth, bone health or neurocognitive outcome. However, ongoing scientific investigations have highlighted the presence of subtle proatherogenic abnormalities among children with modest elevations in their TSH levels. Although current findings are insufficient to recommend levothyroxine treatment for all children with mild asymptomatic forms of subclinical hypothyroidism, they highlight the potential need for assessment of cardiovascular risk among children with this condition. Increased understanding of the early metabolic risk factors associated with subclinical hypothyroidism in childhood will help to improve the management of affected individuals