Abstract
Two heterometallic Cu(II)/Ni(II) coordination polymers, [Cu(2)(Hbdea)(2)Ni(CN)(4)](n) (1) and [Cu(2)(dmea)(2)Ni(CN)(4)](n)·nH(2)O (2), were successfully self-assembled in water by reacting Cu(II) nitrate with H(2)bdea (N-butyldiethanolamine) and Hdmea (N,N-dimethylethanolamine) in the presence of sodium hydroxide and [Ni(CN)(4)](2-). These new coordination polymers were investigated by single-crystal and powder X-ray diffraction and fully characterized by FT-IR spectroscopy, thermogravimetry, elemental analysis, variable-temperature magnetic susceptibility measurements, and theoretical DFT and CASSCF calculations. Despite differences in crystal systems, in both compounds, each dinuclear building block [Cu(2)(μ-aminopolyalcoholate)(2)](2+) is bridged by diamagnetic [Ni(CN)(4)](2-) linkers, resulting in 1D (1) or 2D (2) metal-organic architectures. Experimental magnetic studies show that both compounds display strong antiferromagnetic coupling (J = -602.1 cm(-1) for 1 and -151 cm(-1) for 2) between Cu(II) ions within the dimers mediated by the μ-O-alkoxo bridges. These results are corroborated by the broken symmetry DFT studies, which also provide further insight into the electronic structures of copper dimeric units. By reporting a facile self-assembly synthetic protocol, this study can be a model to widen a still limited family of heterometallic Cu/Ni coordination polymer materials with different functional properties.