The coordination chemistry of a flexible Ndonor ligand di(3-pyridylmethyl)amine (dpma) with silver salts has been investigated. Six new silver coordination polymers, namely, [Ag(dpma(5), and [Ag(dpma)](PF 6 ) (6), have been prepared by slow diffusion reactions. All the polymeric structures of compounds 1−6 are described as topologic binodal networks in terms of Ag and dpma building blocks. Compounds 1−4 show a onedimensional ladder-like chain structure, with both Ag and dpma as three-connected T-nodes; compound 5 is an uncommon one-dimensional metallamacrocycle-based chain structure, with Ag as two-connected I-node and dpma as threeconnected T-node; compound 6 is a two-dimensional honeycomb-like layer structure, with both Ag and dpma as threeconnected Y-nodes. Within the structures, the dpma ligand adopts a variety of structure conformations including gauche−trans− anti (1 and 2), trans−trans−anti (3 and 4), trans−trans−syn (3), gauche−gauche−syn (5), and trans−gauche−syn (6) conformations. For these Ag−dpma coordination polymers, the structural diversity and complexity are most likely attributed to the different coordinating nature, hydrogen-bonding propensity, and templating effect of the counteranions and solvent molecules. Solution studies suggest that compounds 1−6 would disaggregate to break down the polymeric structures and then to give multiple rapidly exchanging solution species in DMSO or acetonitrile. The thermal stabilities of compounds 1−6 are examined. In addition, the photoluminescent properties of compounds 1−6 are investigated in the solid state at room temperature.

A novel M(2)L(4) tetragonal metalloprism, [(NO(3)(-))⊂{Cu(2)(μ-Hdpma)(4)}(NO(3))(2)](NO(3))(5) (1), was prepared from the self-assembly reaction of Cu(NO(3))(2)·3H(2)O and flexible clip-like organic ligand di(3-pyridylmethyl)amine (dpma) under acidic conditions. The cationic prismatic hollow structure of 1 hosts one nitrate anion via both metal-ligand dative bonds and electrostatic interactions. Metalloprism 1 can dissolve in water and its prismatic structure remains intact as supported by ESI-MS data. When metalloprism 1 was treated with sodium thiocyanate and sodium azide in aqueous solutions, two polymeric coordination architectures, [Cu(μ-Hdpma)(2)(NCS)(2)](NO(3))(2) (2) and [Cu(μ-dpma)(2)(μ-1,1-N(3))(μ-1,3-N(3))] (3), formed at room temperature, respectively. Polymer 2 has a two-dimensional sheet structure showing a simple rhombic 4(4)-sql topology in network connectivity, whereas polymer 3 gives a three-dimensional uninodal pcu net. The conformation of the flexible ditopic ligand is varied from a trans-trans-syn conformer in 1 to a trans-trans-anti conformer in 2 and to a trans-gauche-anti conformer in 3. The observations imply the occurrence of structural transformation from a discrete metalloprism into polymeric coordination architectures via a decoordination/rearrangement process. Magnetic studies of metalloprism 1 suggest that the two Cu(II) centers are weakly antiferromagnetically coupled. The spins communicate via the nitrate template while the Cu···O(nitrate) interactions are weak. For polymer 3, a ferromagnetically coupled system (J(2) = +17.6 cm(-1)) is operative between two Cu(II) centers bridged by end-on azidos and an antiferromagnetic coupling (J(1) = -7.7 cm(-1)) between two Cu(II) centers with end-to-end azidos. In contrast to relatively large coupling values of the reported examples, the weak ferromagnetic interaction results from insufficient spin delocalization between two Cu(II) centers.

Self-assembly of Cu(NO ) ⋅3 H O and di(3-pyridylmethyl)amine (dpma) with addition of different acids (HNO , HOAc, HCl, HClO , HOTf, HPF , HBF , and H SO ) afforded a family of anion-templated tetragonal metallocages with a cationic prismatic structure of [(G )⊂{Cu (Hdpma) }] (G =NO , PF , SiF ) with different ligating anions/solvents (NO , Cl , ClO , OTf , H O) outside the cage. Systematic competitive experiments have rationalized the tendency of anion templation towards the formation of metallocages [(G )⊂{Cu (Hdpma) }] as occurring in the order SiF ≈PF >NO >SO ≈ClO ≈BF . This sequence is mostly elucidated by shape control over size selectivity and electrostatic attraction between the cationic {Cu (Hdpma) } host and the anionic guests. In addition, these results have also roughly ranked the anion coordination ability in the order Cl , ClO , OTf >NO >BF , CH SO . Magnetic studies of metallocages 1 t and 2-4 suggest that the fitted magnetic interaction, being weakly magnetically coupled overall, is interpreted as a result of the combination of intracage ferromagnetic coupling integrals and intercage antiferromagnetic exchange; both contributions are very weak and comparable in strength.

A series of Cu(II) metallo-assemblies showing anion-directed structural variations, including five metallocages [(G(n-) )⊂{Cu2 (Hdpma)4 }]((8-n)+) (A(-) )8-n (G(n-) =NO3 (-) , ClO4 (-) , SiF6 (2-) , BF4 (-) , SO4 (2-) ; A(-) =NO3 (-) , ClO4 (-) , BF4 (-) , CH3 SO4 (-) ; Hdpma=bis(3-pyridylmethyl)ammonium cation), a complex double salt, namely, (H3 dpma)4 (CuCl4 )5 Cl2 , and a coordination chain, namely, [Cu2 (dpma)(OAc)4 ], are reported. The influence of the anion can be explained by its coordinating ability, the affinity of which for the Cu(II) center interferes significantly with metallocage formation, and its shape, which offers host-guest recognition ability to engage in weak metal-anion coordination and hydrogen bonding to the organic ligand, which are responsible for metallocage templation. EPR studies of these metallocages in the powder phase at room temperature and 77 K showed a trend of the g values (g|| >2.10>g⊥ >2.00) indicating a dx2-y2 -based ground state with square-pyramidal geometry for the Cu(II) centers. The magnetism of these metallocages can be interpreted as the result of a combination of relatively small magnetic coupling integrals and a substantial contribution of temperature-independent paramagnetism (TIP). The weak magnetic interaction is corroborated by the results of DFT calculations and the EPR spectra. Availability of the low-lying state for spin population was confirmed by a magnetization study, which revealed a magnetic moment approaching 2Nβ, which would explain the presence of the larger TIP term.