Cyano-bridged heterometallic complexes directed by binuclear copper units

A tridentate N,O-donor, 1,3-bis(3,5-dimethylpyrazol-1-yl)propan-2-ol (HL), has been employed to synthesize cyano-bridged complexes and six heterometallic complexes with Cu₂L₂] or Cu₂L₂(H₂O)] have been generated by using slow diffusion. With slightly different synthetic conditions, subtle variations in the crystal structures of the complexes occur. Cu₂L₂]Fe(CN)₅NO]?2CH₃CN (1) and Cu₂L₂]Fe(CN)₅NO]?H₂O (2), synthesized in different solvents with the same precursor, exhibit a very similar 1-D zig-zag chain motif in different space groups, P2₁ and P-1, respectively. Similarly, Cu₂L₂(H₂O)]Ni(CN)₄]·H₂O (3) and Cu₂L₂]Ni(CN)₄]?H₂O (4), synthesized with different diffusion methods, feature trinuclear and 1-D zig-zag chain structures, which indicates a solvent effect of water. Cu₂L₂(H₂O)]₂Cu₂L₂]W(CN)₈]₂·8H₂O (5) is composed of two W(CN)₈]^3? and three Cu₂L₂]²⁺ units. In the octanuclear structure, W(CN)₈]^3? and one Cu₂L₂]²⁺ bridge and the other two Cu₂L₂]²⁺ are terminal to stop extending the 1-D structure. CuL]Ag_2.24Cu_0.76(CN)₄] (6) exhibits a discrete structure, in which the complex anion forms a unique 2-D 6³ network and the complex cations are inserted in the space between two adjacent networks. Magnetic properties of 1 and 4 are discussed.