Functionalised azetidines as ligands: species derived by selective alkylation at substituent-nitrogen.
Selective functionalisation of the tridentate ligand 1-(2-aminoethyl)-3-methyl-3-(2-pyridyl)azetidine at its terminal amino-nitrogen atom can be readily achieved by both reductive alkylation and simple alkylation reactions to give tri-, quadri-, quinque- and sexi-dentate derivatives. Simple alkylation by 2-picolinyl chloride provides the only example of a second reaction pathway where the azetidine ring of the reactant has undergone activation towards ring opening. Structural characterisation of the Cu(II) complexes of these ligands has revealed several remarkable aspects of their solid-state coordination chemistry, including the formation of infinite helical aggregates through pi-stacking and tetramerisation through carboxylate bridging, as well as further examples of the crystallisation of mixed species found to be rather common with complexes of the parent ligand.
Lee
Young Hoon
YH
Department of Chemistry, Kyungpook National University, Daegu 702-701, South Korea.
Harrowfield
Jack M
JM
Kim
Jong Seung
JS
Kim
Yang
Y
Lee
Min Hee
MH
Lim
Woo Taik
WT
Park
Yu Cheol
YC
Thuéry
Pierre
P