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Nonwoven fibers of cellulose triacetate (CTA) were continuously electrospun by using DMSO/chloroform co-solvent system and the size and morphology of fibers were investigated. It was found that the concentration of 8wt% CTA fibers were obtained from DMSO/chloroform with volume ratio of 1:1, 3:2, 2:1, 3:1. The average diameters of CTA fiber was decreased with decreasing chloroform content in the mixed solvent. The minimum diameter of the continuous electrospun cellulose triacetate fibers obtained in this work ranged between 210 and 880 nm.

Three new coordination polymers with different architectures, {[Zn2(bta)(2,2′-bipy)2]·H2O}n (1), {[Cd2(bta)(2,2′-bipy)2(H2O)]·H2O}n (2) and [Cd3(bta)(Hbiim)2(H2biim)]n (3), where H4bta = biphenyl-2,2′,4,4′-tetracarboxylic acid, 2,2′-bipy = 2,2′-bipyridine and H2biim = 1H,1′H-2,2′-biimidazole, have been obtained by the reactions of metal nitrates, H4bta, the second ligands and H2O under similar hydrothermal conditions. All the polymers are three-dimensional (3D) constructions with different networks, in which 1, 2 and 3 exhibit a (42·84)-pts, (42·63·8)-sra and (416·65) topology, respectively. The bta ligands in 1–3 adopt η6,μ6-hexadentate, η8,μ5-tetradentate and η10,μ7-decadaldentate coordination modes, respectively, and the corresponding angles of two benzene rings in the ligand of each compound are 45.96°, 54.93° and 52.50°, respectively. This study indicates that the natures of metal ions and the second ligands are crucial factors for self-assemble of coordination polymers.

A new three-dimensional coordination polymer with the formula [Co(bta)0.5(Htz)(H2O)]n ( 1 ) (H4bta = biphenyl-2,2′,6,6′-tetracarboxylic acid and Htz = 1,2,4-triazole), has been hydrothermally synthesized and structurally characterized. The structure of 1 can be considered as two-dimensional [Co(bta)(H2O)]n layers, consisting of one-dimensional [Co(COO)]n chains, which are separated by bta ligands, and neutral Htz pillars. The variable temperature magnetic property study indicates that there is a weak antiferromagnetic coupling interaction between Co(II) ions, which mainly arises from the antiferromagnetic coupling interaction in the one-dimensional [Co(COO)]n chains through syn–anti carboxylate bridges.

Quaternary phosphonium salts were proved efficient homogeneous catalysts for solvent-free synthesis of cyclic carbonates from carbon dioxide and epoxides. Propylene carbonate was produced in quantitative yield and excellent selectivity. Furthermore, a PEG-supported phosphonium salt was solidified by adding ether and cooling after reaction and recovered by a simple filtration. Hence immobilization of a phosphonium salt on PEG provides an alternative pathway for realizing homogeneous catalyst recycling.

A new three-dimensional coordination polymer with the formula, [Cd4(OH)2(na)6]n (1) (na = nicotinate), has been hydrothermally synthesized and structurally characterized, which can be considered as a uninodal six-connected pcu topology based on butterfly-like [Cd4(μ3-OH)2] SBUs. The polymer exhibits high thermal stability until 355 °C confirmed by thermogravimetric analysis and has potential applications as an optical material.

In the title salt, C8H16N2O42+·2H2PO4−·2H2O, the piperazine ring is located around an inversion center and adopts a chair conformation. The dihydrogen phosphate anions and free water molecules are linked via O—H...O hydrogen bonds into two-dimensional hydrogen-bonding layers, which are further connected through O—H...O and N—H...O hydrogen bonds involving the protonated piperazine into a three-dimensional supramolecular network.

The asymmetric unit of the title compound, [Zn(C7H8N4S)2](NO3)2·2H2O, contains two Zn(pht)2 cations (pht is pyridine-2-carbaldehyde thiosemicarbazone), four nitrate anions and four water molecules. In the cations, each ZnII ion adopts a distorted octahedral coordination geometry, being chelated by two tridentate pht ligands. In the crystal, the cations, anions and water molecules are connected via O—H...O and N—H...O hydrogen bonds into a three-dimensional network.

The tripodal character of the title compound, C33H30N10S3, arises from the three thioether arms surrounding a central amine N atom. The three arms have approximately the same conformation but distinct geometries in a trans–trans–cis conformation, resulting in a short pyridine–sulfanyl N...S distance of 4.320 (7) Å. The distances of the central N atom to the N atoms of three pyridine rings in the arms are 8.305 (7), 8.032 (7) and 5.076 (9)Å. In the crystal, molecules are joined into a three-dimensional supramolecular network via effective π–π stacking between adjacent heterocycles [centroid–centroid distances of 3.700 (3)–4.118 (4) Å between adjacent interlayer pyrimidine rings and 3.676 (4) Å between the pyridine rings].

The asymmetric unit of the title compound, [Fe(C(9)H(4)O(6))(C(12)H(8)N(2))(H(2)O)](n), contains one Fe(II) cation, one 5-carboxy-benzene-1,3-dicarboxyl-ate dianion (Hbtc), one 1,10-phenanthroline (phen) ligand and one water mol-ecule. The Fe(II) centre displays a distorted octa-hedral geometry, being surrounded by one phen ligand, two μ(2)-O atoms of two carboxyl-ate groups from two Hbtc ligands, one O atom from one carboxyl-ate of another Hbtc ligand and one terminal water mol-ecule. One carboxyl-ate group ligates two Fe(II) cations in a μ(1,1) mode, while the other carboxyl-ate groups bonds to only one Fe atom. The crystal structure is stabilized by O-H⋯O hydrogen bonds.

Two new temperature-controlled coordination polymers, {{Ag2.67[(1R,2R,N1S,N2S)-4-bpcd]2}·2.67ClO4·1.33H2O}n (1) and {{Ag[(1R,2R,N1S,N2S)-4-bpcd]}·ClO4·H2O}n (2) [(1R,2R)-4-bpcd = (1R,2R)-N1,N2-bis(pyridin-4-ylmethyl)cyclohexane-1,2-diamine], with congenital chiral centers from the ligand and acquired chiral centers formed by the coordination interaction, have been synthesized via a chiral multidentate organic bridging ligand, in which 1 displays a chiral (6,3) network, while 2 has a (4,4) topology. Circular dichroism (CD) spectra confirmed that the bulk samples are chiral. The frameworks have potential as multifunctional materials due to their luminescent and nonlinear optical (NLO) properties. The present study demonstrates that reaction temperature is a crucial factor for the construction of coordination polymers.

In the crystal structure of the title compound, C(12)H(20)N(3) (+)·Cl(-), the protonated (1R,2R)-(pyridin-4-ylmeth-yl)cyclo-hexane-1,2-diamine cations and chloride anions are linked via N-H⋯N and N-H⋯Cl hydrogen bonds into a three-dimensional network.

In the dimeric title complex, [Ag(2)(C(16)H(8)O(8))(C(12)H(8)N(2))(2)] or [Ag(2)(H(2)bta)(phen)(2)] (H(4)bta = biphenyl-2,2',6,6'-tetra-carb-ox-y-lic acid, phen = 1,10-phenanthroline), each Ag(I) ion displays an approximatively planar-trigonal geometry, being surrounded by one chelating phen ligand and one carboxyl-ate O atom from an H(2)bta ligand. Owing to the the presence of crystallographic twofold rotation axes, the four C atoms bisecting the H~2~bta ligand are located on a special position. Each H(2)bta ligand acts as a bis-monodentate ligand, ligating two Ag(I) ions into a dimeric compound. Inter-molecular O-H⋯O inter-actions are observed in the crystal structure.

In the structure of the title compound, [Cd(C(9)H(7)N(2)O(2)S)(2)(C(10)H(8)N(2))(2)], the complex mol-ecules are located on a crystallographic twofold rotation axis and the Cd(II) ion is octa-hedrally coordinated by two chelating 2,2'-bipyridine ligands and two O atoms from the carboxyl-ate groups of two 2-(benzimidazol-2-ylsulfan-yl)acetate ligands. The two carboxyl-ate ligands adopt a cis configuration with respect to each other. Within each of these ligands, the imidazole fragments are bent back in a loop towards the acetyl groups, forming intra-molecular N-H⋯O hydrogen bonds, which help to stablilize the mononuclear complex. Adjacent mol-ecules are further linked by weak C-H⋯O hydrogen bonds, resulting in a chain along the c axis.

The present crystal structure is the second orthorhombic polymorph of the title compound, C14H12N4. Whereas the structure in Pnma with Z′ = 0.5 is already known [Ikemi et al. (2002). Heterocycl. Commun. 8, 439–442], the present structure crystallizes in the space group Pbca with Z′ = 1. The dihedral angle between the two phenyl rings is 23.5 (4)° and the dihedral angles between central ring and the phenyl rings are 41.0 (3) and 26.3 (5)°. In the 4-amino-1,2,4-trizole fragment, the C=N distances are 1.321 (3) and 1.315 (3) Å, which are much shorter than the C—N distances of 1.367 (3) and 1.357 (3) Å. In the crystal, adjacent molecules are linked by N—H...N hydrogen bonds.

The title compound, C(10)H(10)N(8), resides on a crystallographic symmetry center and features an essentially planar mol-ecule [r.m.s. deviation = 0.278 (1) Å]. In the C=N-N=C fragment, the C=N distance is 1.3017 (18) Å and the N-N distance is 1.403 (2) Å. In the crystal, adjacent mol-ecules are linked by N-H⋯N hydrogen bonds into a three-dimensional network.

In the title compound, [Zn(C(7)H(4)FO(2))(2)(C(5)H(6)N(2))(2)] or [Zn(fa)(2)(2-pa)(2)] (Hfa is 2-fluoro-benzoic acid and 2-pa = pyridin-2-amine), the asymmetric unit contains one Zn(II) cation, two fa ligands and two 2-pa ligands, wherein the Zn(II) displays a distorted tetra-hedral geometry, being surrounded by two monodentate fa ligands with Zn-O distances of 1.962 (2) and 1.976 (3) Å, and by two 2-pa ligands with distances involving pyridyl N atoms of 2.069 (2) and 2.056 (2) Å. The F atoms of the fa ligands are equally disordered over two sites, viz. the 2- and 6-positions of fa. The mononuclear complex mol-ecules are joined by N-H⋯O and N-H⋯F hydrogen bonds into a two-dimensional layer, which is further constructed into a three-dimensional supra-molecular network by weak C-H⋯F inter-actions and effective π-π stacking [centroid-centroid separation of 3.74 (3) Å] between the inter-layer aromatic rings and adjacent heterocycles.

The title compound, C(39)H(33)N(9)S(3), features a mesitylene unit substituted with three thio-ether arms. The distances from the center of mesitylene unit to the N atoms of the three pyridine rings in the arms are 10.05 (1), 9.94 (3) and 8.79 (3) Å. The crystal structure shows weak intra-molecular C-H⋯N hydrogen bonds.

The asymmetric unit of the title compound, [Zn(C12H8N5)2(C2H8N2)]·CH3OH·2H2O, contains a ZnII cation, octahedrally coordinated by two 3-(2-pyrid­yl)-5-(4-pyrid­yl)-1,2,4-triazolate anions, a chelating ethane-1,2-diamine mol­ecule, a methanol solvent mol­ecule, and two crystal water mol­ecules. In the crystal packing, complex mol­ecules are linked by hydrogen bonds into a two-dimensional layer.

The title compound, C8H6N4O2, is a difunctional compound with a carboxylate and a tetrazole residue. In the crystal structure, molecules are linked into two-dimensional sheets by intermolecular N—H...O and O—H...N hydrogen bonds.

In title compound, [Cd(C(9)H(6)N(2)O(2)S)(C(12)H(8)N(2))](n), the Cd(II) atom is in a distorted tetra-gonal-pyramidal environment, coordinated by one chelating 1,10-phenanthroline ligand, one chelating 2-(1,3-benzimidazol-2-ylsulfan-yl)acetate (bia) ligand bound through one N atom and one O atom of the carboxyl group, and one N atom from a second bia ligand. Each bia ligand acts as bridge between Cd(II) ions, forming one-dimensional coordination polymers along [010], with a shortest Cd⋯Cd distance of 4.27 (2) Å.