ABSTRACT
Three novel mixed-ligand lithium aggregates, [(mu(3)-EDBP)Li(2)](2)[(mu(3)-(n)Bu)Li(0.5Et(2)O)](2) (1), [(mu(3)-EDBP)Li(2)](2)[(mu(3)-OBn)Li](2) (2), and [(mu(3)-EDBP)Li(2)](2)[(mu(3)-OCH(2)CH(2)OCH(2)CH(3))Li](2) (3), have been synthesized and structurally characterized. The reaction of 2,2'-ethylidene-bis(4,6-di-tert-butylphenol) (EDBP-H(2)) with 3.6 molar equiv of (n)BuLi gives 1 in high yield. 1 further reacts with benzyl alcohol and 2-ethoxyethanol respectively to yield the corresponding products 2 and 3. Experimental results show that 2 and 3 efficiently initiate the ring-opening polymerization of L-lactide in a controlled fashion, yielding polymers with very narrow polydispersity indexes in a wide range of monomer-to-initiator ratios.
Subject(s)
Lactic Acid/chemistry , Lithium/chemistry , Organometallic Compounds/chemical synthesis , Polyesters/chemistry , Polyesters/chemical synthesis , Benzyl Alcohol/chemistry , Cyclization , Ethylene Glycols/chemistry , Magnetic Resonance Spectroscopy , Molecular Conformation , Molecular Structure , Organometallic Compounds/chemistry , Polymers/chemical synthesis , Polymers/chemistryABSTRACT
The reactions of AlMe3 in diethyl ether with 1 molar equiv of 2,2'-methylenebis(4-methyl-6-tert-butylphenol) (MMBP-H2), 2,2'-methylenebis(4,6-di-tert-butylphenol) (MDBP-H2), and 2,2'-ethylidenebis(4,6-di-tert-butylphenol) (EDBP-H2) afford series of four-coordinate monomeric aluminum aryloxides, MeAl(O-O)(OEt2), 1-3 (1, (O-O) = MMBP; 2, (O-O) = MDBP; 3, (O-O) = EDBP). In THF, 1 molar equiv of EDBP-H2 reacts with AlMe3 to provide the THF-coordinated complex MeAl(EDBP)(THF) 4. However, in the absence of a coordinating solvent, the reaction of EDBP-H2 with AlMe3 yields the dimeric complex [MeAl(mu-EDBP)]2 (5). Complex 5 further reacts with Et4NCl, Et4NBr, and Ph3PO to afford the corresponding monomeric ionic complex [Et4N][MeAl(EDBP)(X)] (6, X = Cl; 7, X = Br) and the neutral complex [MeAl(EDBP)(O=PPh3)] (8), respectively. Complexes 1, 2, 4 and 6-8 are subjected to X-ray structure analyses, and the solid state structures reveal that the conformations of the eight-membered heterocycles are governed by the formation of the unusual C-H...X hydrogen bonds.
Subject(s)
Health Status , Health , Nutritional Status , Adolescent , Child , Growth , Humans , Morbidity , UkraineSubject(s)
Activities of Daily Living , Child Rearing , Health Status , Health , Child , Humans , Urban PopulationABSTRACT
Noradrenaline (NA) and isopropyladrenaline in a dose of 11 microM/kg were shown to activate in vivo Na+, K+-ATPase and Mg2+-ATPase in the mouse renal microsomal fraction. NA (10(-6) M) increased the activity of Na+, K+-ATPase in vitro and did not affect the activity of Mg2+-ATPase in the hepatic and renal microsomal fractions. NA did not significantly affect in vivo the mitochondrial ATPases activity in the presence of various stimulators (Mg, dinitrophenol, bicarbonate) and inhibitors (oligomycin, bicyclohexyl carbodiimide) in the mouse liver and kidneys. cAMP (10(-6) M) activated Na+, K+-ATPase in vitro reduced the activity of Mg2+-ATPase in the microsomal fraction, and did not change the activity of the mitochondrial ATPases in the mouse liver and kidneys. The following scheme of the mechanism of catecholamine (CA) effect on Na+, K+-ATPase is suggested: CA leads to beta-adrenoreceptors leads to adenylate cyclase leads to cAMP leads to protein kinase leads to Na+, K+-ATPase. The mechanism of Mg2+-ATPase regulation is discussed.
