Samarium complexes of a σ-/π-pyrrolide/arene based macrocyclic ligandCCDC reference numbers 763508, 763509and 763510for 1, 2aand 2brespectively. . For crystallographic data in CIF or other electronic format see DOI: 10.1039/c002514n.

Autor: Ilango, Sougandi, Vidjayacoumar, Balamurugan, Gambarotta, Sandro
Předmět:
Zdroj: Dalton Transactions: An International Journal of Inorganic Chemistry; Jul2010, Vol. 39 Issue 29, p6853-6857, 5p
Abstrakt: A bis-pyrrolide macrocyclic ligand [L = trans-calix[2]benzene[2]pyrrole(H)] containing two aromatic phenyl rings in the macrocycle backbone was reacted with SmCl3(THF)3to afford the corresponding [LSmIIICl] (1) complex. Its crystal structure showed the ligand adopting the σ-bonding mode with the pyrrolide moieties and the π-bonding with the two aromatic rings. Reaction of 1with MeLi in THF gave a mixture of two compounds. The major was a C–H activated complex [LSmIII(THF)] (2a) where the bonding mode of the pyrrolide rings was switched from σ- to π- as a result of the deprotonation and metallation of one of the two aromatic rings. The minor component was an unusual [(L)SmIII(HL′)] (2b) complex containing both a regular ligand and an “N-confused” macrocyclic ligand. The two ligands wrapped the Sm center with the regular ligand adopting a bonding mode similar to 1. The second ligand instead acted as a simple σ-bonded monodentate ligand, only using one nitrogen atom of one pyrrolide ring. However, this particular pyrrolide moiety has been isomerized by shifting the ring attachment to the macrocycle (N-confused system). In addition, the second pyrrolide ring has been protonated at the nitrogen atom. Complex 2bwas obtained as major compound and in analytically pure form by reacting 1with NaH. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index