Dinuclear and octanuclear Mn(II) complexes with μ2-C, μ2-N(pyrrolide), and μ-η1:η5-(pyrrolide) bridges:: A structural and magnetic study

Reaction of the dinuclear [(CH2SiMe3)(mu-CH2SiMe3)Mn(THF)](2) (1) with an equivalent amount of 1,1-dipyrrolylcyclohexane afforded two compounds depending on the solvent employed. Reaction carried out in THF afforded the dinuclear {[1,1-(mu-C4H3N)(C4H3N)C6H10]Mn(THF)(2)}(2)(.)2(THF) (2) while reaction in toluene yielded the octanuclear and cyclic cluster {[1,1-(mu,eta(1):eta(5)-C4H3N)(2)C6H10]Mn}(8)(.)4(toluene) (3). The magnetism in all three cases is dominated by intramolecular antiferromagnetic exchange with strong coupling in 1(J = -85 cm(-1)), and in 2 (J = -23.2 cm-1), whereas substantially weaker coupling through the sigma/pi-bonded dipyrrolide bridges (J = -3.3 cm(-1)) was observed within the cyclic and octameric 3.