One-dimensional cyanide-bridged Fe(III)–Mn(II) magnetic complexes with different configurations derived from a new pentacyanoiron(III) building block

Two cyanide-bridged heterometallic Fe III –Mn II complexes with formula {[Mn(bipy)(H 2 O)] 2 [Fe(2-CH 3 im)(CN) 5 ] 2 } n · n CH 3 OH·4 n H 2 O ( 2 ) (bipy = 2,2′-bipyridine) and {[Mn(MAC)][Fe(2-CH 3 im)(CN) 5 ]} n · n DMF·3 n H 2 O ( 3 ) (MAC = 2,13-dimethyl-3,6,9,12,18-pentaazabicyclo-[12.3.1]octadeca-1(18),2,12,14,16-pentaene) have been successfully synthesized by assembling a newly designed pentacyanoiron(III) precursor [PPh 4 ] 2 [Fe(CN) 5 (2-CH 3 im)]·2CH 3 OH ( 1 ) and two Mn(II) compounds containing bulky ancillary organic ligands as segments, and characterized by elemental analysis, infrared (IR) spectroscopy, and X-ray structure determination. X-ray diffraction analysis revealed one-dimensional (1D) ladder-like double or linear single infinite-chain structures for complex 2 and 3 , respectively, indicating the obvious steric influence of the auxiliary ligand(s) on the structural type. Experimental and theoretical investigations on the magnetic properties of the complexes showed the antiferromagnetic coupling between the cyanide-bridged low-spin Fe(III) ion and high-spin Mn(II) ion.