The synthesis of 28-and 36-membered P,N-containing cyclophanes with two 1,5-diaza-3,7-diphosphacyclooctane (17-21 %) whereas the condensations with the participation of 1,3-bis(4'-aminophenoxy) benzene containing three phenylene groups in the spacer are much less selective, and 36-membered cyclophanes have been obtained in low yields (7-9 %). It shows the strong influence of the starting phosphine nature on the selectivity of the Mannich-like condensation reactions. The treatment of 28-membered P-pyridylethyl substituted cyclophanes with hydrochloric acid in chloroform leads to the corresponding monohydrochlorides as a result of the protonation of pyridyl nitrogen atom, and in the solutions the fast migration of the proton between all pyridyl nitrogen centers is observed.Keywords: Macrocycle, cyclophane, pyridyl-containing phosphine, diamine, condensation, covalent self-assembly.Новые P,N -содержащие циклофаны с экзоциклическими пиридилсодержащими заместителями при атомах фосфора
The first representatives of the tetranuclear gold(i) complexes of P,N-containing cyclophanes with two 1,5-diaza-3,7-diphosphacyclooctane rings incorporated into the macrocyclic core have been obtained. The complexation leads to a change in ligand conformations so that the diazadiphosphacyclooctane fragments of the complexes adopt twist-chair conformations, and two of the four gold(i) ions are located over and under the partially collapsed macrocyclic cavity. The complexes demonstrate moderate solid-state green emission.
In order to synthesize new iron (II) complexes of 1,5-diaza-3,7-diphosphacyclooctanes with a wider variety of the substituents on ligands heteroatoms (including functionalized ones, namely, pyridyl groups) and co-ligands, it was found that these ligands with relatively small phenyl, benzyl, and pyridin-2-yl substituents on phosphorus atoms in acetonitrile formed bis-P,P-chelate cis-complexes [L2Fe(CH3CN)2]2+ (BF4)2−, whereas P-mesityl-substituted ligand formed only monoligand P,P-complex [LFe(CH3CN)4]2+ (BF4)2−. 3,7-dibenzyl-1,5-di(1′-(R)-phenylethyl)-1,5-diaza-3,7-diphosphacyclooctane reacted with hexahydrate of iron (II) tetrafluoroborate in acetone to give an unusual bis-ligand cationic complex of the composition [L2Fe(BF4)]+ BF4−, where two fluorine atoms of the tetrafluoroborate unit occupied two pseudo-equatorial positions at roughly octahedral iron ion, according to X-ray diffraction data. 1,5-diaza-3,7-diphosphacyclooctanes replaced tetrahydrofurane and one of the carbonyl ligands of cyclopentadienyldicarbonyl(tetrahydrofuran)iron (II) tetrafluoroborate to form heteroligand complexes [CpFeL(CO)]+BF4−. The structural studies in the solid phase and in solutions showed that diazadiphosphacyclooctane ligands of all complexes adopted chair-boat conformations so that their nitrogen atoms were in close proximity to the central iron ion. The redox properties of the obtained complexes were performed by the cyclic voltammetry method.
Under conditions of physiological stress of different aetiologies, cells of any organism undergo compensatory metabolic changes. The specificity of such changes primarily depends on functional and histochemical features of the tissues of the body. The purpose of this work was to describe the functioning of the main components of the oxidation-reduction system, (ORS, the Krebs cycle, and the antioxidant system) in the myocardium of geese under conditions of the physiological stress occurring during the transition from the embryonic to postnatal development. It has been experimentally established that in the second half of geese embryogenesis, the content of short-chain fatty acids is significantly increased and the content of long-chain polyunsaturated fatty acids in their myocardium decreases. During the first two weeks of the postnatal period, there are reversible changes in the fatty acid composition of this tissue. The second half of the embryogenesis is characterized by the activation of dehydrogenases of the Krebs cycle in the low variability of antioxidant enzyme activity. At the same time, the experiment demonstrated an increase in the antioxidant activity coefficient, with the exception of its significant reduction on the first day of postnatal ontogenesis. The functioning of the ORS in the myocardium of geese is characterized by the presence of correlations between the nature of the changes of 19 investigated components (dehydrogenases of the Krebs cycle, antioxidant enzymes, lipid peroxidation products, antioxidant activity coefficient, fatty acids, their total content and unsaturation) and structuring of the system into two clusters.
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