Synthesis of Isomeric Tb3+‐Phthalocyanine Double‐Decker Complexes Depending on the Difference in the Direction of Coordination Plane and Their Magnetic Properties.

A C4h symmetrically substituted phthalocyanine, 1,8,15,22‐tertrakis(2,4‐dimethylpent‐3‐oxy)phthalocyanine (H2TdMPPc), was used to synthesize Tb3+‐phthalocyanine double‐decker complexes ([Tb(TdMPPc)2]s). Because H2TdMPPc has C4h symmetry, S,S, R,R, and meso isomers of [Tb(TdMPPc)2] were obtained depending on the difference in the direction of the coordination plane of two C4h‐type phthalocyanines with respect to a central Tb3+ ion. We investigated the physical properties of these [Tb(TdMPPc)2] isomers, including their single‐ion magnetic properties, and found that the spin‐reversal energy barrier (Ueff) of the meso isomer was apparently higher than that of the enantiomers. Detailed crystal structural analyses indicated that the meso isomer has a more symmetrical structure than do the enantiomers, thereby suggesting that the higher Ueff of the meso isomer originated from the more highly symmetrical structure. [ABSTRACT FROM AUTHOR]