Chiral photomagnets compose a class of multifunctional molecule-based materials with light-induced alteration of magnetization and chiral properties. The rational design and synthesis of such assemblies is a challenge, and only few such systems are known. Herein, the remarkable octacyanide-bridged enantiomeric pair of 1-D chains [Cu((R,R)-chxn)(2)](2)[Mo(CN)(8)]center dot H2O (1R) and [Cu((S,S)-chxn)(2)](2)[Mo(CN)(8)]center dot H2O (IS) exhibiting enantiopure structural helicity, which results in optical activity in the 350-800 nm range as confirmed by natural circular dichroism (NCD) spectra, is reported. The photomagnetic effects of 1R, 1S, and lrac result from the blue light excitation (436 nm) of the photomagnetically active octacyanidomolybdate(IV) ions. In the excited state Mo rv Hs centers with S = 1 couple antiferromagnetically with the neighboring Cu-II centers with J(CUMO) values of -1.3, -1.0, and -1.1 cm(-1) for 1R, 1S, and lrac, respectively. The values of thermal relaxation energy barriers have been estimated as 142 and 356 K for 1R and IS, being comparable with the energy range of the thermal bath. The value for lrac reveals a significantly lower value of 75 K. On the basis of these results the value of g(Mo)(HS) has been estimated to be in the range 4.8-5.8.