Abstract. Two one-dimensional cyano-bridged coordination polymers [Ln(tmphen) 2 (DMF) 2 Mo(CN) 8 ] ϱ [Ln = Eu (1) and Gd (2), tmphen = 3,4,7,8-tetramethyl-1,10-phenanthroline, DMF = N,N-dimethylformamide] were synthesized and characterized. The structural determination reveals that complexes 1 and 2 consist of 1D chains, in which