Topological Diversity of Supramolecular Networks Constructed from Copper(II) Aminoalcohol Blocks and 2,6-Naphthalenedicarboxylate Linkers: Self-Assembly Synthesis, Structural Features, and Magnetic Properties

A series
of copper­(II) aminoalcohol derivatives [Cu2(μ-dmea)2­(μ-nda)­(H2O)2]n·2nH2O (1), [Cu2(μ-Hmdea)2­(μ-nda)]n­·2nH2O (2), [Cu2(μ-Hbdea)2­(μ-nda)]n­·2nH2O (3), and [Cu2(H4etda)2­(μ-nda)]­·nda­·4H2O (4) were generated by aqueous medium self-assembly
at ∼25 °C from copper­(II) nitrate, various aminoalcohols
[N,N′-dimethylethanolamine
(Hdmea), N-methyldiethanolamine (H2mdea), N-butyldiethanolamine (H2bdea), or N,N,N′,N′-tetrakis­(2-hydroxyethyl)­ethylenediamine (H4etda) for 1–4, respectively],
sodium hydroxide, and 2,6-naphthalenedicarboxylic acid (H2nda). They were isolated as crystalline solids and fully characterized
by IR and electron paramagnetic resonance spectroscopy, electrospray
ionization mass spectrometry (ESI–MS(±)), thermogravimetric,
elemental, and single-crystal X-ray diffraction analyses. The latter
revealed that 1–3 are one-dimensional
(1D) coordination polymers assembled from dicopper­(II) aminoalcohol
blocks and μ-nda linkers, whereas 4 is a discrete
zero-dimensional (0D) dimer composed of two [Cu­(H4etda)]2+ fragments interlinked by the μ-nda moiety. In spite
of some structural similarities, the main distinctive features of 1–4 arise from the different H-bonding
patterns driven by the crystallization H2O molecules, thus
giving rise to a further extension of the structures [1D →
3D (1, 2), 1D → 2D (3), or 0D → 3D (4)] into distinct supramolecular
networks. Their topological analysis disclosed very complex multinodal
nets with unique (1, 2, 4)
or rare (3) topologies, which, upon further simplification,
furnished a binodal 4,6-connected net with the sqc513 topology in 1, a trinodal 3,4,6-connected net with the 3,4,6L6 topology
in 3, and trinodal 3,4,6- or 3,4,8-connected nets with
undocumented topologies in 2 and 4, respectively.
The magnetic susceptibility studies of 1–3 indicate a strong antiferromagnetic coupling between the
CuII atoms through the μ-alkoxo bridges [J = −470(2), −100(2), and −590(1) cm–1, respectively], which was described by the Bleaney–Bowers
dinuclear model. In contrast, 4 is devoid of any significant
magnetic interaction within the dicopper­(II) units.