Browsing by Author "Cocu, Maria"

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    AGENȚI DE COORDINARE DE TIP BAZE SCHIFF – SURSE GENERATIVE DE EMISIE
    (CEP USM, 2024) Danilescu, Olga; Culicova, Olga; Cocu, Maria; Bulhac, Ion
    This work elucidates the structure-property correlation and comparative study of the photoluminescent activity of three lumonophore Schiff base coordination agents H2L1, H2L2 and H2L3 (H2L1 = 2,6-diacetylpyridine bis(isonicotinoylhydrazone), H2L2 = 2,6-diacetylpyridine bis(nicotinoylhydrazone) and H2L3 = 2,6-diacetylpyridine bis(picolinoylhydrazone)) and their precursors. The fluorescent emissions of both the starting substances and the coordination agents show emission bands in the blue region (500-550 nm). The comparative study of the photoluminescent activity shows a 100-fold increase in the luminescence intensity of the coordination agents H2L1 and H2L2 compared to that of their precursors, and the coordination agent H2L3 showed a 50-fold increase in luminescence intensity compared to that of the starting substances.
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    COORDINATION COMPOUNDS AND CHEMICAL COMPOSITIONS WITH ANTIOXIDANT PROPERTIES
    (2023) Bulhac, Ion; Ștefîrță, Anastasia; Brînză, Lilia; Coropceanu, Eduard; Voloșciuc, Leonid; Cocu, Maria
    In the paper are presented the main results that argue the antioxidant effect of BACC and some chemical compositions on plants. The anti-stress action of the new preparations - Conimid, Difecoden, Fludisec, Polyel, Galmet and Thiogalmet, is provided by increasing the antioxidant protection capacity due to the decrease of the content of malondialdehyde, intensification of the activity of antioxidant enzymes, increase in the content of non-enzymatic antioxidants with low molecular mass. The possibilities of optimizing the resistance of plants to oxidative stress, caused by drought, and stabilization of plant productivity are promising. The biological performance of plants pre-treated with BACC and antioxidant preparations are more fully realized under both optimal moisture and moderate drought conditions.
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    SINTEZA POLIMERULUI COORDINATIV HETEROMETALIC Mn(II)/Cd(II), STUDIUL STRUCTURAL ȘI AL FOTOLUMINESCENȚEI
    (CEP USM, 2024) Danilescu, Olga; Croitor, Lilia; Bouroș, Polina; Kulikova, Olga; Cocu, Maria; Bulhac, Ion; Chumakov, Iurie
    Based on solvothermal synthesis, self-assembly of the heptadentate 2,6-diacetylpyridine bis(nicotinoylhydrazone) schiff base ligand (H2l) and Mn(II) and Cd(II) salts has led to formation a heterometallic {[Mn0.3Cd0.7l]·dmf·0.25H2O}n (1) coordination polymer. This compound was characterized by IR spectroscopy, single-crystal X-ray diffraction, as well as the photoluminescente proprietes were studied.