A new coordination polymer, [Zn(HBTC)(BPE)0.5(H2O)]n·nH2O (1) with an extended 1D ladderlike metal-organic framework (MOF) has been synthesized and structural characterized by single-crystal X-ray diffraction method. Structural determination reveals that, in compound 1, the Zn(II) ion is four-coordinated in a distorted tetrahedral geometry, bonded to one nitrogen atom from one BPE ligand, and three oxygen atoms from two monodentate carboxylate groups of two HBTC(2-) ligands and one coordinated water molecule. The HBTC(2-) acts as a bridging ligand with a bis-monodentate coordination mode, connecting the Zn(II) ions to form a one-dimensional (1D) [Zn(HBTC)] chain. Two 1D chains are then interlinked via the connectivity between the Zn(II) ions and anti-BPE liagnds to complete the 1D ladderlike MOF. Adjacent 1D Ladders are further extended to a 2D hydrogen-bonded layered network through the intermolecular O-H · · · O hydrogen bond between the carboxylic group and carboxylate group of interladder HBTC(2-) ligand. Adjacent 2D layers are then packed orderly in an ABAB-type array via the intermolecular interactions of combined π-π interaction and O-H · · · O hydrogen bonds to form a 3D supramolecular architecture exhibiting 1D channels intercalated with guest water molecules. The reversible solid-state structural transformation between crystalline 1 with 1D ladderlike framework and its dehydrated powder 2, [Zn(HBTC)(BPE)0.5]n, with 2D framework via the displacement of coordinated water molecule to HBTC(2-) ligand, by thermal de/rehydrated processes has been verified by PXRD measurements. The emission of 1 and 2 is ascribed to a ligand-based transition.

A new coordination polymer, [Zn(dpe)(bdc)]·4H(2)O (ZndB; dpe=1,2-bis(4-pyridyl)ethane, bdc(2-)=dianion of benzenedicarboxylic acid), which possesses a 3D metal-organic framework (MOF) has been synthesized and structurally characterized. This 3D MOF is constructed by the assembly of helical channels filled with guest water molecules in both inner and outer regions of the channel. The resulting network also creates a 2D water layer containing hydrogen-bonded (H(2)O)(16) rings as the basic building units. Thermogravimetric and powder X-ray diffraction measurements of ZndB revealed a two-step weight loss of water molecules with a reversible water adsorption/desorption process in the inner channel for the first stage, and irreversible water desorption in the outer channel for the second stage. This spongelike property is manifested by the excimer emission originating from interaction between dpe (π*) and the other dpe (π) of the proximal helical channel, which is highly sensitive to the environmental perturbation. Powder X-ray analyses reveal that the dehydration process induces the readjustment of dpe π-π stacking distance/orientation, which results in dramatic luminescence changes from dim pale blue (λ(em)≈470 nm) upon hydration to bright white-light generation (broad, λ(em)≈500-550 nm) upon water depletion, accompanied by a ≈100-fold increase in the emission intensity.

A unique three-dimensional (3D) supramolecular compound, [Co(dpe)(BTC)(H 2 O)][Co(dpe)(BTC)(H 2 O) 3 ]-[Co(dpe)(HBTC)(H 2 O)][Co(dpe) 2 (H 2 O) 3.5 (EtOH) 0.5 ]•1.5H 2 O (1; dpe = 1,2-bis(4-pyridyl)ethane and H 3 BTC = benzenetricarboxylic acid), has been synthesized and structurally characterized by the single-crystal X-ray diffraction method. Compound 1 consists of four coordination polymers (CPs), two are two-dimensional (2D) layered metal−organic frameworks (MOFs) with (4,4) topology of [Co(dpe)(BTC)(H 2 O)] − and [Co(dpe)(HBTC)(H 2 O)], whereas the other two are onedimensional (1D) polymeric chains of [Co(dpe)(BTC)(H 2 O) 3 ] − and [Co(dpe)(H 2 O) 3.5 (EtOH) 0.5 ] 2+ . The 3D supramolecular architecture of 1 is constructed via the penetration of interdigitated double-layered 2D rectangular-grid frameworks by two 1D coordination polymeric chains and entangled tightly by the subtle combination of intermolecular hydrogen bonding and π−π interactions among the four CPs. Controlled heating of the as-synthesized crystal 1 at ∼160 °C produces a desolvated 1 and accompanying color-changing behavior from pink to deep-blue, and the deep-blue desolvated 1 regenerates the pink rehydrated crystal with the chemical formula of [Co(dpe 2) upon exposure to water vapor. The structural determination of 2 shows almost the same structural characteristics as that of 1 with the only difference being the replacement of disordered coordinated solvent (half H 2 O and half EtOH molecules) by H 2 O and the numbers of solvated water molecules. The cyclic thermogravimetric analysis and powder X-ray diffraction measurements of desolvated 1 demonstrate a reversible rehydration/dehydration property, which is associated with solid-state structural transformation and thermally induced UV−vis absorption properties.

The synthesis, crystal structures, magnetic properties, and single molecular conductances of two linear trinickel string complexes, [Ni3(mpta)4(NCS)2] (2) and [Ni3(mpta)4(CN)2] (3), supported by sulfur‐containing Hmpta (1) ligands are presented (Hmpta = 4‐methylpyridylthiazolylamine). Compounds 2 and 3 possess a 1D trinickel backbone coordinated by four mpta– ligands. Within the trinickel framework, the two terminal high‐spin (S = 1) Ni ions are strongly antiferromagnetically coupled (J = –91 cm–1 in 2 and –79 cm–1 in 3). As the axial CN– ligand is very basic and strongly pulls the terminal Ni ions away from the central Ni ion, the Ni–Ni distances in 3 (ca. 2.52 Å) are longer than those in 2 (ca. 2.47 Å). The lengthening of the Ni–Ni bond lengths causes 3 to exhibit weaker antiferromagnetic interactions and lower single molecular conductance [R = 7.1 (±1.5) MΩ for 2 and R = 11.1 (±3.9) MΩ for 3].

Three Nd(iii)–ndc2− coordination polymers were constructed using ndc2− ligands with hybrid coordination modes to generate octahedral SBUs for 1 and rod-shaped SBUs for 2 and 3, respectively.