Jhy-Der Chen

Adjusting the frameworks of polymeric silver(I) complexes with 2-aminopyrimidyl ligands by changing the counterions

The complexes [Ag2(L)2(SO4)]∞, (L = 2-aminopyrimidine) 1, [Ag(L)1.5(ClO4)]∞, 2, and [Ag(L)(OAc)·2H2O]∞, 3, were prepared by layering the aqueous solution of the corresponding Ag(I) salt with L in ethanol, while [Ag(L′)(NO3)]∞, 4, and [Ag(L′)(ClO4)·H2O]∞, 5, were prepared by refluxing AgNO3 and AgClO4, respectively, with 2-amino-4,6-dimethylpyrimidine (L′) in H2O. Reaction of Ag2SO4 with L′ in methanol afforded the complex [Ag4(L′)2(SO4)2(H2O)4]∞, 6. In complex 1, the L ligands are coordinated to the Ag(I) metal centers in new tridentate fashions, forming 2-D pleated molecular sheets which are interlinked by the SO42− anions to form a 3-D layer structure. Complex 2 forms a pleated molecular sheet consisting of twenty four-membered metallocycles, involving six Ag ions which are bridged by six L ligands through the pyrimidyl nitrogen atoms. Complex 3 forms linear chains with sinusoidal geometry, which are interlinked through extensive Ag⋯Ag interactions (Ag⋯Ag = 3.102 A) to form 2-D wavy rectangular grids. Complex 4 forms single-strained helical coordination polymers, which are interlinked through a series of Ag⋯O interactions (2.667 and 2.699 A) to form 2-D chair like grids. The silver atoms of 5 are bound to the nitrogen atoms of two symmetry-related L′ ligands in a distinctly non-linear geometry, forming zigzag chains. The structure of 6 consists of clusters of the formula [Ag8(L′)4(SO4)4(H2O)8], which are interlinked through L′ ligands to form 2-D sheets. The μ1-O, μ2-O′- bonding mode of the SO42− anion in complex 6 is unique for Ag(I) complexes. Their thermal properties have been investigated by using differential scanning calorimetry (DSC) and thermogravimetric analyses (TGA)

Ligand isomerism-controlled structural diversity of cadmium(II) perchlorate coordination polymers containing dipyridyladipoamide ligands

The syntheses, structures and ligand conformations of three Cd(II) coordination polymers [Cd(L1)(ClO4)2]∞ [L1 = N,N′-di(2-pyridyl)adipoamide], 1, {[Cd(L2)2(CH3OH)2](ClO4)2·2CH3OH}∞ [L2 = N,N′-di(3-pyridyl)adipoamide], 2 and [Cd(L3)2(ClO4)2(CH3CH2OH)2]∞ [L3 = N,N′-di(4-pyridyl)adipoamide], 3, are reported. Their structures have been characterized by X-ray crystallography. Complex 1 forms 1D zigzag chains, while complex 2 forms 2D pleated sheets which are positioned in an ABAB manner. Complex 3 shows a rare 3D entanglement from parallel polycatenation of 3-fold interpenetrated square layers. While the L1 ligands in 1 adopt AAAtrans conformations and the L2 ligands in 2 adopt GAGtrans conformations, the L3 ligands in 3 adopt AAAtrans and AGAtrans conformations. The structural types of the Cd(II) coordination polymers can be directed by ligand isomerism.

Interpenetrated and polycatenated nets of Cd(II) coordination networks from mixed N,N′-dipyridyladipoamide and dicarboxylate ligands

The synthesis, structures and properties of five Cd(II) coordination networks: [Cd(bpdc)(L1)]n [L1 = N,N′-di(4-pyridyl)adipoamide; H2bpdc = 4,4′-biphenyldicarboxylic acid], 1; {[Cd2(1,4-ndc)2(L1)2(H2O)]·H2O·2DMF}n (1,4-H2ndc = naphthalene-1,4-dicarboxylic acid), 2; {[Cd(OBA)(L1)]·2H2O}n [H2OBA = 4,4′-oxybis(benzoic acid)], 3; {[Cd(SDA)(L1)]·1.5H2O}n (H2SDA = 4,4′-sulfonyldibenzoic acid), 4; and {[Cd(1,4-ndc)(L2)(H2O)]·2H2O}n [L2 = N,N′-di(3-pyridyl)adipoamide], 5, are reported. Complexes 1 and 2 show the pcu and fsd topologies with 2- and 3-fold interpenetrating modes, respectively, and complex 4 exhibits a 2-fold 2D → 2D parallel interpenetration network containing a rotaxane-like motif. Complex 3 is a 1D → 2D polycatenane derived from the helical channels, and the 2D layers are further mutually interdigitated, whereas complex 5 is a 2D → 3D polycatenane based on the undulating sql sheets. These five complexes show different thermal and luminescent properties and the CO2 capture is preferable to N2 in the gas sorption for the desolvated product of 1.

Roles of I⋯I and Ag⋯I interactions on the self-assembly of Ag(I) complexes containing 2-amino-5-iodopyrimidine; formation of the unique Ag⋯I⋯I⋯Ag interaction

A series of silver(I) complexes [Ag(L)(NO3)]4, (L = 2-amino-5-iodopyrimidine), 1, [Ag(L)(PF6)]∞, 2, and [Ag(L)(ClO4)]∞, 3, have been prepared by the reactions of AgX (X = NO3−, PF6− and ClO4−, respectively) with L. All the complexes have been structurally characterized by X-ray crystallography, confirming that complex 1 forms sixteen–membered metallocycles interlinked by I⋯I and Ag⋯O interactions to create a porous structure. Complexes 2 and 3 form helical chains, with different periods of 22.584 and 11.465 A, respectively. In addition to the Ag⋯O interaction and hydrogen bonds, the unique discrete Ag⋯I⋯I⋯Ag and linear ⋯(Ag⋯I⋯I⋯Ag)n⋯ interactions with short I⋯I and Ag⋯I contacts were found in complexes 2 and 3, respectively, to support their supramolecular structures.

Roles of halide anions in the structural diversity of Zn(II) complexes containing the flexible N,N′-di(4-pyridyl)adipoamide ligand

A series of Zn(II) complexes with N,N′-di(4-pyridyl)adipoamide ligands, {[ZnX2(L)]·H2O}∞ (X = Cl, 1, Br, 2 and I, 3; L = N,N′-di(4-pyridyl)adipoamide), [Zn2X4(L)2]·2DMF (X = Cl, 4 and Br, 5) and [Zn2I4(L)2]·4DMF·C4H10O, 6, were prepared and their structures determined by X-ray crystallography. Complexes 1 and 2 form double-stranded helical chains which are supported by the N–H⋯O and O–H⋯X hydrogen bonds involving the guest water molecules and the halide anions, whereas 3 shows sinusoidal chains which are interlinked by the N–H⋯O hydrogen bonds and π–π interactions. Complexes 1–3 represent a unique example that the halide anions show significant effect on folding and unfolding of the Zn(II) double-stranded helical coordination polymers. Complexes 1–3 can be transformed to the corresponding complexes 4–6, which are dinuclear with 34-membered metallocycles. In these complexes, the chloride and bromide anions play the same role in the crystal structures, while the iodide anion is distinct.

Structure-directing roles of auxiliary polycarboxylate ligands in the formation of Zn(II) and Cd(II) coordination polymers based on a flexible N,N′-di(3-pyridyl)dodecanediamide

Reactions of the flexible N,N′-di(3-pyridyl)dodecanediamide (L) with Zn(II) and Cd(II) metal salts in the presence of different polycarboxylic acids under hydrothermal conditions afforded five new coordination polymers, [Zn(2,4-PDC)(L)(H2O)]∞ (2,4-H2PDC = 2,4-pyridinedicarboxylic acid), 1, {[Zn(1,3,5-HBTC)(L)]·2H2O}∞ (1,3,5-H3BTC = 1,3,5-benzenetricarboxylic acid), 2, {[Zn(3,4-PDC)(L)]·0.5L}∞ (3,4-H2PDC = 3,4-pyridinedicarboxylic acid), 3, {[Cd(1,2-BDC)(L)(H2O)]·0.5L}∞ (1,2-H2BDC = 1,2-benzenedicarboxylic acid), 4, and {[Cd(1,3,5-HBTC)(L)1.5]·2H2O}∞, 5, which have been structurally characterized by X-ray crystallography. Complexes 1 and 2 manifest quintuple and double helices formed by zinc ions and L ligands, which are supported by 2,4-PDC2− and 1,3,5-HBTC2− anions, respectively, to construct the rare single-walled metal–organic nanotubes. Complex 3 shows 1D fish-bone chains and complexes 4 and 5 display 2D pleated grids with helical and looped carboxylate chains, respectively, supported by the L ligands. Complexes 1–3 represent a unique example of the polycarboxylate ligands showing a significant effect on folding and unfolding of the Zn(II) helical coordination polymers, and they are also important in determining the number of helices. The L ligands in 1, 2 and 4 adopt a bidentate bonding mode, and a unique monodentate bonding mode for the dipyridyl amide ligand is found in 3 and 5, resulting in various types of ligand conformations.

Crystal engineering of coordination polymers containing flexible bis-pyridyl-bis-amide ligands

The contribution of flexible bis-pyridyl-bis-amide (bpba) ligands, which are also known as versatile ligands possessing various active coordination atoms (N and O) and different flexible –CH2– skeletons, is significant in the construction of coordination polymers. In this Highlight, structures of the different dimensional networks based on the flexible bpba ligands with or without participation of auxiliary polycarboxylate ligands are discussed, along with an overview of the preparations and conformations of the ligands.

Structural diversity of Ni(II) coordination polymers containing dipyridyl amide and angular dicarboxylate ligands: synthesis, structures and magnetism

Four new Ni(II) coordination polymers containing dipyridyl amide and angular dicarboxylate ligands, {[Ni(L1)(MBA)]·2H2O}∞ [L1 = N,N′-di(4-pyridyl)-adipoamide; H2MBA = diphenylmethane-4,4′-dicarboxylic acid], 1, {[Ni(L1)(OBA)]·H2O}∞ [H2OBA = 4,4′-oxybis(benzoic acid)], 2, {[Ni(L1)(SDA)]·2H2O}∞ (H2SDA = 4,4′-sulfonyldibenzoic acid), 3, and {[Ni2(L2)(SDA)2]·6H2O}∞ [L2 = N,N′-di(4-pyridyl)suberoamide], 4, have been synthesized by hydrothermal reactions and were structurally characterized by single crystal X-ray diffraction analyses. Complex 1 is a 1D → 2D polycatenane derived from the helical channels, and the 2D layers are further mutually interdigitated, whereas complex 2 forms 2D rhombic grids with the (6,4) topology, which are interwoven with each other to give a two fold 2D → 2D interpenetrating net. Complex 3 shows the 1D looped chain structure, and complex 4 shows 2D layers which catenate to each other to form a 2D → 3D inclined polycatenation framework with the new (42·68·8·104)(4)2 topology. The C–X–C (X = CH2, 1; O, 2; and SO2, 3 and 4) angles are important in determining the structural diversity. Complex 1 exhibits a different magnetic reaction in the ZFC and FC processes, revealing the existence of a meta-state of ferromagnetic ordering, whereas the activation energies of spin–orbit coupling and antiferromagnetic interaction of complexes 2–4 are directed by the N⋯N and Ni⋯Ni distances, respectively.

Dimolybdenum complexes of bis(2-pyridyl)amine (Hdpa) ligand and its anion (dpa−); transformation of chelating η2-Hdpa to bridging η2-dpa−

Abstract The reaction of trans-Mo2(O2CCR3)2X2(PPh3)2 with 1 equiv. of Hdpa (Hdpa=bis(2-pyridyl)amine) in CH2Cl2 afforded the complex cis-Mo2(O2CCR3)2X2(η2-Hdpa) (R=H, X=Cl, 1; R=H, X=Br, 2; R=F, X=Cl, 3, R=F, X=Br, 4). Layering of a Mo2(O2CCF3)4 solution in CH2Cl2 with Hdpa in ether produced red and yellow crystals, which were characterized as Mo2(η2-dpa)4 (5), and Mo2(O2CCF3)4(η1-HO2CCF3)2 · 2Hdpa (6), respectively. Complex 5 can also be prepared by reaction of trans-Mo2(O2CCR3)2X2(PPh3)2 with excess Hdpa. Their UV–Vis and IR spectra have been recorded and the structures of 4, 5 and 6 have been determined. The Hdpa ligand in 4 is coordinated to the metal centers via two terminal pyridine nitrogen atoms with a cis-N conformation. The dpa− ligands in 5 are bridged to the metal centers via one terminal nitrogen atom and the central nitrogen atom. The aligned-N conformation of the dpa− ligand is stabilized by both the intramolecular Mo⋯N and C–H⋯N interactions. In 6, the CF3COOH ligands coordinate to the metal centers in the axial positions with η1-bonding modes and the Hdpa molecules adapt cis-N conformations.

Structural directing roles of isomeric phenylenediacetate ligands in the formation of coordination networks based on flexible N,N′-di(3-pyridyl)suberoamide

Reactions of the flexible N,N′-di(3-pyridyl)suberoamide (L) with Cu(II) salts in the presence of the isomeric phenylenediacetic acids under hydrothermal conditions afforded three new coordination networks, {[Cu(L)(1,2-pda)]·H2O}n (1,2-H2pda = 1,2-phenylenediacetic acid), 1, {[Cu(L)(1,3-pda)]·2H2O}n (1,3- H2pda = 1,3-phenylenediacetic acid), 2, and {[Cu(L)(1,4-pda)]·2H2O}n (1,4-H2pda = 1,4-phenylenediacetic acid), 3, which have been structurally characterized by X-ray crystallography. Complex 1 forms a single 3,5-coordinated 3D net with the (42·65·83)(42·6)-3,5T1 topology, which can be further simplified as a 6-coordinated (412·63)-pcu topology. Complex 2 is a 5-fold interpenetrated 3D structure with the (65·8)-cds topology, which exhibits the maximum number of interpenetration presently known for cds and complex 3 is the first 1D self-catenated coordination network. The ligand isomerism of the phenylenediacetate ligands is important in determining the structural types of the Cu(II) coordination networks based on the flexible L ligands.