Juan Yang

Guest-induced expanding and shrinking porous modulation based on interdigitated metal–organic frameworks constructed by 4,4′-sulfonyldibenzoate and barium ions

A series of barium-4,4′-sulfonyldibenzoate (sdba) coordination polymers, namely, [Ba(μ2-OH2)(sdba)(H2O)3]·0.5H2O (1), [Ba(μ2-OH2)(sdba)(H2O)3]·0.5ben·H2O (2), [Ba(μ2-OH2)(sdba)(H2O)3]·0.5tolu·H2O (3), [Ba(μ2-OH2)(sdba)(H2O)3]·0.5bpy·H2O (4), [Ba(μ2-OH2)(sdba)(H2O)3]·0.25bim·H2O (5), [Ba(μ2-OH2)(sdba)(H2O)3]·0.5dfb·0.25H2O (6) and [Ba(μ2-OH2)(sdba)(H2O)3]·3.5H2O (7) (ben = benzene, tolu = toluene, bpy = 2,2′-bipyridine, bim = 1,4-bis(imidazol-1-yl)butane, dfb = 1,3-difluoro-benzene (a fragment of fluconazole)), have been hydrothermally synthesized and characterized by single crystal X-ray diffraction, powder X-ray diffraction, elemental analysis, IR spectra, and TG analyses. Compounds 1–7 are built upon similar sidearm-containing 2D bilayer motifs, and the adjacent layers are stacked in a mutual interdigitation, such that channels are created. The channels form a hydrogen-bonded interior for guest molecules. In practice, compounds 1 and 7 contain different quantities of free water molecules as guests in the channels, whereas compounds 2–6 contain ben, tolu, bpy, bim and dfb molecules as well as free water molecules in their channels, respectively. The different interlayer distances and free void spaces of 1–7 indicate the effect of guest-induced expanding and shrinking porous modulation, and give a clue to the dynamic arrangement in this system. This indicates the obtained compounds (1–7) are categorized as a member of a new generation of compounds tending towards functional porous coordination polymers. In addition, the photoluminescent properties for all the compounds (1–7) were investigated in detail.

Helicity controlled by the chirality of amino acid: two novel enantiopure chiral 3D architectures containing fivefold interwoven helices

Two novel three-dimensional (3D) chiral coordination polymers, namely [Zn4(btc)2(Hbtc)(L-His)2(H2O)4]·1.5H2O (L-1) and [Zn4(btc)2(Hbtc)(D-His)2(H2O)4]·1.5H2O (D-1), have been assembled from zinc salt with mixed ligands 1,3,5-benzenetricarboxylic acid (H3btc) and chiral histidine (His). Their structures were determined by single-crystal X-ray diffraction analyses, elemental analyses, infrared (IR) spectra, X-ray powder diffraction, circular dichroism (CD) spectra, and thermogravimetric (TG) analysis. Compounds L-1 and D-1 are enantiomers and exhibit unique 3D chiral frameworks containing fivefold interwoven helices, which represent the first examples of chiral metal–amino acid complexes containing n-fold interwoven helices. Furthermore, the helices in L-1 are left-handed, while those in D-1 are right-handed, which indicate that the handedness of helices can be controlled by the chirality of His bound to the metal. More wonderfully, the 3D framework can be simplified to a (3,4)-connected chiral net with an unprecedented (4·92)(4·94·11) topology. Moreover, the luminescent properties of compound L-1 are discussed.

An unusual 3D 8-connected entangled coordination network with coexistence of self-threading, polythreading and interpenetration

An 8-connected entangled metal–organic framework has been synthesized and characterized, which not only represents the first entangled framework with coexistence of self-threading, polythreading and interpenetration, but also represents the highest connected topology presently known for self-threading and polythreading systems.

Syntheses, structures and properties of five entangled coordination polymers constructed with trigonal N-donor ligands

Based on the mixed-ligand system, five new entangled coordination polymers have been synthesized, namely, [Co1.5(1,3-bdc)1.5(tib)(H2O)] (1), [Ni(1,3-bdc)(tib)(H2O)2]·0.5H2O (2), [Cu(Hbtc)(Htpim)] (3), [Co(bpndc)(pytpy)(H2O)]·0.5H2O (4), and [Ni(bpndc)(pytpy)(H2O)]·0.5H2O (5), (1,3-bdc = 1,3-benzenedicarboxylate, btc = 1,3,5-benzenetricarboxylate, bpndc = 4,4′-benzophenone dicarboxylate, tib = 1,3,5-tris(1-imidazolyl)benzene, Htpim = 2,4,5-tri(4-pyridyl)-imidazole, pytpy = 2,4,6-tris(4-pyridyl)pyridine). Their structures were determined by single-crystal X-ray diffraction analyses and further characterized by elemental analyses, IR spectroscopy and TG analyses. Compound 1 exhibits a new trinodal (3,4,4)-connected 3D self-penetrating framework with (83)2(63.82.9)2(84.9.10) topology. Compound 2 displays an interesting 2D → 3D polythreading framework constructed from sidearm-containing 2D 63-hcb nets. Compound 3 exhibits an unusual (2D → 3D) entangled array with the coexistence of polythreading and interdigitation self-assembled from sidearm-containing 2D double-edged nets. Compounds 4 and 5 both show an intriguing 3-fold interpenetrated PtS-type (4,4)-connected 3D framework containing meso-helices. In addition, the magnetic properties of compounds 1–5 have been investigated in the temperature range 2–300 K.

Bis[1-cyclo-propyl-6-fluoro-4-oxo-7-(1-piperazin-4-ium-1-yl)-1,4-dihydro-quinoline-3-carboxyl-ate-κO,O]bis-(nitrato-κO)copper(II).

In the title complex, [Cu(NO3)2(C17H18FN3O3)2], the CuII ion is located on an inversion center. It exhibits a distorted octahedral geometry, being coordinated by six O atoms, four from two ciprofloxacin ligand molecules (L), which act as bidentate ligands, and two from two nitrate anions. In the ligand, the piperazine ring has a chair conformation and the quinoline system is essentially planar [maximum deviation = 0.097 (2) Å]. One of the nitrate O atoms is disordered over two positions [occupancy ratio = 0.51 (6):0.49 (6)]. There is a C—H⋯F interaction in the complex. In the crystal, molecules are linked via N—H⋯O hydrogen bonds generating a two-dimensional network lying parallel to (111). The presence of C—H⋯O interactions leads to the formation of a three-dimensional structure. The title complex was prepared by hydrothermal synthesis, and the hexahydrate form of this complex, synthesized by conventional methods, has been reported previously [Hernandez-Gil et al. (2009 ▶). Polyhedron, 28, 138–144].