- Tytuł:
-
Kompleksy jonów metali d- i f-elektronowych z N-tlenkiem pirydyny i związkami pochodnymi : badania spektroskopowe
Complexes of d- and f-metal ions with pyridine N-oxide and its derivatives: spectroscopic studies - Autorzy:
- Hnatejko, Z.
- Powiązania:
- https://bibliotekanauki.pl/articles/171812.pdf
- Data publikacji:
- 2011
- Wydawca:
- Polskie Towarzystwo Chemiczne
- Tematy:
-
kompleksy jonów metali
jony metali
N-tlenki pirydyny
spektroskopia
complexes
metal ions
pyridine N-oxides
spectroscopy - Opis:
- This article reviews results of studies, collected in the literature, related to complexation abilities of pyridine N-oxides, including forms and properties of dand f-metal ion complexes with this group of ligands. In this paper the synthetic pathways of the ligands, based on an oxidation of the corresponding heterocyclic compounds are presented (Scheme 3) [2, 4, 5]. Substituted pyridine N-oxides form an interesting group of compounds, which have found numerous applications [296-299, 314-318]. They have been used in catalysis, crystal engineering, synthesis of coordination polymers, as well as drugs and components in pharmaceutical chemistry [300-309]. Some of them are useful in destroying of microorganisms and the HIV virus [277, 278, 303-307]. Moreover, they are important compounds in the thermal and photochemical oxidation processes [296-299]. The complexes of metal ions with the N-oxide ligands can be formed by binding an oxygen atom of the N›O group, and/or by binding the substituents present in the aromatic ring, e.g. oxygen atoms of carboxylic groups. The complexes can be obtained in monomeric [64, 159], dimeric [58] or polymeric forms [60, 153, 175]. The formation of polymeric forms is more effective when the distance between the positions of COOH and N›O groups in the aromatic ring increases [168]. Complexes of Ln3+ ions and particularly of Eu3+ with pyridine N-oxides are good luminescent materials, better than their heterocyclic counterparts [180, 211]. The emission intensity of europium ions in these systems depends on the efficiency of the LMCT (ligand-metal charge transfer) and LMET (ligand-metal energy transfer) transitions, as well as on electron-donor properties of the substituents present in the pyridine N-oxide ring [37, 132, 155]. A special role in the complexation of Ln3+ ions plays cryptands, which can encapsulate the metal ion. This process protects the metal ion from a penetration of its first coordination sphere by solvent molecules or counterions [245, 246]. The complexes of europium(III) with macromonocyclic, macrobicyclic and acyclic ligands, equipped with photoactive units such as pyridine N-oxide, 2,2'-bipyridine-N,N'-dioxide or 3,3'-biisoquinoline-2,2'-dioxide in solutions, solid states, and incorporated in a silicate matrices by sol-gel method, gained a lot of attention [247-274].
- Źródło:
-
Wiadomości Chemiczne; 2011, 65, 5-6; 461-501
0043-5104
2300-0295 - Pojawia się w:
- Wiadomości Chemiczne
- Dostawca treści:
- Biblioteka Nauki
Artykuł