Benzoic hydroxamate-based iron complexes as model compounds for humic substances: synthesis, characterization and algal growth experiments
作者:Ewelina Orlowska、Alexander Roller、Hubert Wiesinger、Marc Pignitter、Franz Jirsa、Regina Krachler、Wolfgang Kandioller、Bernhard K. Keppler
DOI:10.1039/c5ra25256c
日期:——
complexes in pure water and seawater was monitored over 24 h by means of UV-Vis spectrometry. The ability to release iron from the synthesized model complexes has been investigated with algae growth experiments.
Described is a protective solution for avoiding ischemic, storage or ischemia/reperfusion to organs, or to isolated cell systems, or to tissue components after perfusion, surgery, transplantation, or cryopreservation and subsequent reperfusion, which contains alkali ions, and if need be also alkaline earth ions as the electrolyte, a buffer e.g. on a histidine derivation basis, as well as a polyol and/or a saccharide, has an osmolarity of about 290 mosm/l to about 350 mosm/l, as well as a pH value of about 6.8 to about 7.4, and to which hydroxamic acid, and/or one or more hydroxamic acid derivatives are added.
Protektive Lösung zur Verhinderung von Ischämieschäden
申请人:Dr. Franz Köhler Chemie GmbH
公开号:EP1362511A1
公开(公告)日:2003-11-19
Beschrieben wird eine protektive Lösung zur Vermeidung von Ischämieschäden an Organen, oder an isolierten Zellsystemen oder Gewebeteilen nach Perfusion, Operation, Transplantation oder Kryokonservierung und anschließender Reperfusion, welche als Elektrolyte Alkali- gegebenenfalls auch Erdalkaliionen, einen Puffer sowie einen Polyol und/oder einen Zucker enthält, eine Osmolarität von etwa 290 mosm/l bis etwa 350 mosm/l sowie einen pH-Wert von etwa 6,8 bis etwa 7,4 aufweist, und der Hydroxamsäure und/oder eines oder mehrere Hydroxamsäurederivate zugesetzt sind.
Preparation of Site-Differentiated Mixed Ligand and Mixed Ligand/Mixed Metal Metallacrowns
作者:George Psomas、Ann J. Stemmler、Catherine Dendrinou-Samara、Jeffrey J. Bodwin、Manuela Schneider、Maria Alexiou、Jeff W. Kampf、Dimitris P. Kessissoglou、Vincent L. Pecoraro
DOI:10.1021/ic000578+
日期:2001.3.1
Assembly reactions that can prepare reliably regioselective metallamacrocyclic complexes have been a target in the development of metalracrowns. To this end, a series of mixed ligand and mixed Ligand/mixed metal metallacrowns have been synthesized in high yield and structurally characterized. Two distinct connectivities have been observed in these types of metallacrowns. The monomeric, vacant metallacrown with mixed ligand composition [12-MCNi(II)Ni(Hshi)2(pko)2-4] (1a) shows the connectivity pattern [-O-Ni-O-N-Ni-N-](2) while the other Ni metallacrowns, [12-MCNi(II)N(shi)2(pko)2-4] (2a) and the coupled [12-MCNi(II)N(shi)2(pko)2-4] [12-MCNi(II)N(shi)3(pko)-3] (3a) fused metallacrowns as well as the mixed metal Mn-Ni metallacrown [12-MCNi(II)Mn(III)N(shi)2(pko)2-4] (4a), follow the pattern [-Ni-O-N-](4). Also, three distinct arrangements of the chelate rings around the metal ions have been observed. The syntheses an completely general, allowing for the substitution of different ligands into the metallacrown core. Compounds 1 and 4 show the 6-5-6--5-6-5-6-5 arrangement, compounds 2 and 3(1) the 6-6-5-5-6-6-5-5, and the 3(2) component the 6-6-5-5-6-5-6-5. The obtained structures can be rationalized by balancing the charge at each metal site in the metallacrown. Variable temperature magnetic susceptibility measurements show that exchange interactions for all the compounds are weak and dominantly antiferromagnetic (e.e., 2a gives an exchange coupling of J = -1.2 cm(-1) with g = 2.2). In solution, the metallacrowns are shown to be stable both to decomposition and ligand exchange.
THE BECKMANN REARRANGEMENT OF 2,4-DIHYDROXY-BENZHYDROXAMIC ACID DERIVATIVES<sup>1</sup>