Wyniki wyszukiwania - BazTech

Ograniczanie wyników

2 Wiadomości Chemiczne

2 1999

Znaleziono wyników: 2

Liczba wyników na stronie

Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych: dibenzotetraaza[14]annuleny

Sortuj według:

Ogranicz wyniki do:

Dibenzotetraaza[14]annuleny. Cz.2.

Eilmes Julita, Ptaszek Marcin

Wiadomości Chemiczne

1999

[Z] 53, 5-6

329-347

'Dibenzotetraaza[14]annulenes. Part II' presents an overview of the transition and main groups metal compounds of the title macrocyclic ligands. The results of the crystal structure determination are also summarized.(...)

Dibenzotetraaza[14]annuleny. Cz.1.

Eilmes Julita, Ptaszek Marcin

Wiadomości Chemiczne

1999

[Z] 53, 5-6

306-328

The title dibenzotetraaza[14]annulenes belong to the class of the synthetic tetraaza macrocyclic ligands of bioinorganic relevance. Their similarity to porphyrins makes them attractive as models of important biological systems like for example hemoproteins (hemoglobin, myoglobin), cytochromes and metalloenzymes (e.g. oxygenses, peroxidases, catalase). Dibenzotetraaza[14]annulene and porphyrin ligand both have four coplanar nitrogen donor atoms and substantial bond unsaturation and delocalization in the macrocyclic framework. However, the dibenzotetraaza[14]annulenes are Hückel anti-aromatic (4n), whereas the porphyrins are fully delocalized aromatic (4n+2). There is also remarkable difference in the confoormation of the macrocyclic ligand which is flat in porphyrins and taa system (R1=R3=H) and saddle-shaped in the case of other dibenzotetraaza[14]annulenes (R1=R3?H). The conformation of the ligands greatly influences the metal coordination geometries in their metal complexes. Structure of the dibenzotetraaza[14]annulenes is discussed in details in part II. The purpose of this article is to provide the readers with the preparative methods of the synthesis of various dibenzatetraaza[14]annulenes. Reactivity of the macrocyclic framework is also reviewed, as a method of further modification of the ligand structure. (...)