The Building Block [Fe III (pzphen)(CN) 4 ] – and its Lanthanide Complexes: Synthesis, Crystal Structure, and Magnetic Properties

The cyanide building block [Fe III (pzphen)(CN) 4 ] – and its four lanthanide complexes [{Fe III (pzphen)(CN) 4 } 2 Ln III (H 2 O) 5 (DMF) 3 ] · (NO 3 ) · 2(H 2 O) · (CH 3 CN) [ Ln = Nd ( 1 ), Sm ( 2 ), DMF = dimethyl formamide] and [{Fe III (pzphen)(CN) 4 } 2 Ln III (NO 3 )(H 2 O) 2 (DMF) 2 ](CH 3 CN) [ Ln = Gd ( 3 ), Dy ( 4 )] were synthesized and structurally characterized by single‐crystal X‐ray diffraction. Compounds 1 and 2 are ionic salts with two [Fe III (pzphen)(CN) 4 ] – cations and one Ln III ion, but compounds 3 and 4 are cyano‐bridged Fe III ‐ Ln III heterometallic 3d‐4f complexes exhibiting a trinuclear structure in the same conditions. Magnetic studies show that compound 3 is antiferromagnetic between the central Fe III and Gd III atoms. Furthermore, the trinuclear cyano‐bridged Fe III 2 Dy III compound 4 displays no single‐molecular magnets (SMMs) behavior by the alternating current magnetic susceptibility measurements.