Cai-Hong Chen

Linear silver isonicotinamide complex extended by arenedisulfonate via hydrogen bonds and weak Ag⋯O interactions

Four novel supramolecular frameworks constructed by complex cation [Ag(INA)2]+ (INA = isonicotinamide) and 1,5-naphthalenedisulfonate (1,5-NDS, compound 1), 2,6-naphthalenedisulfonate(2,6-NDS, compound 2), biphenyldisulfonate (BPDS, compound 3) and 4,4′-biphenyletherdisulfonate (PEDS, compound 4) anions were synthesized and characterized by X-ray single crystal diffraction, elemental analyses and IR spectra. The [Ag(INA)2]+ building blocks were extended into well-ordered supramolecular frameworks by complementary hydrogen bonds and weak Ag–O interaction with the sulfonate group. Ligand-supported weak argentophilic interactions are observed in compounds 2 and 4. The linkers of the disulfonate groups play an important role in the self-assembly process, and a total of twelve assembly patterns could be predicted for the frameworks constructed by [Ag(INA)2]+ and arenedisulfonate anions.

Solid-state structures of group 1 and group 2 metal 1,5-naphthalenedisulfonates: systematic investigation of lamellar three-dimensional networks constructed by metal arenedisulfonate

Seven Group 1 and Group 2 1,5-naphthalenedisulfonates (1,5-nds) have been synthesized and structurally characterized by single-crystal X-ray diffraction, IR spectroscopy and thermal gravimetric analysis. For Group 1 metal complexes, with M = Li(+) (1), Na(+) (2) and K(+) (3), all crystallize in the same space group (P2(1)/c) with the same composition, [M(2)(1,5-nds)(H(2)O)(2)]. They adopt similar three-dimensional packing arrangements with the metal-sulfonate inorganic layers pillared by naphthalene rings. However, the coordination behavior of three metal cations toward the SO(3)(-) group and water molecule are different, resulting in different architectures for the inorganic portion. For Group 2 complexes with M = Mg(2+) (4), Ca(2+) (5), Sr(2+) (6) and Ba(2+) (7), Mg(2+) shows no direct coordination by the SO(3)(-) group while Ca(2+) is coordinated by four SO(3)(-) groups and a two-dimensional network is formed. Complexes (6) and (7) are isostructural, adopting the same three-dimensional, inorganic-organic pillared framework as seen for (1)-(3). The coordination behavior of the metal cations in these structures neatly illustrates the increase in coordination strength with decreasing charge/radius ratio for Group 1 and Group 2 metal cations with large organic anions.

Synthesis and crystal structures of four nickel(II) 1,5-naphthalenedisulfonate compounds

AbstractFour nickle(II) 1,5-naphthalenedisulfonate (1,5nds) complexes, namely [Ni(H2O)6] (1,5nds) (1), trans-[Ni(en)2(H2O)2](1,5nds)·2H2O (2), [Ni(tren)(H2O)2](1,5nds)·H2O (3), and [Ni(dien)2](1,5nds)·2H2O (4), where en = ethylenediamine, tren = tris(2-aminoethyl)amine, and dien = diethylenetriamine, have been synthesized and structurally characterized. Compound 1 crystallizes in space group P21/c, with a = 13.200(2) Å, b = 6.6197(10) Å, c = 9.6001(14) Å, and β = 92.005(3)° compound 2 crystallizes in space group C2/c, with a = 15.698(2) Å, b = 13.006(2) Å, c = 12.845(2) Å, and β = 119.262(4) Å compound 3 crystallizes in space group P

Conglomerate crystallization behavior of racemic [Co(N4)(aminoacidato)]2+ complexes

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ZnFe2O4/MWCNTs composite with enhanced photocatalytic activity under visible-light irradiation

, with a = 8.8971(10) Å, b = 11.5440(13) Å, c = 11.9169(14) Å, α = 77.254(2)°, β = 74.079(2)°, and γ = 82.162(2)° compound 4 crystallizes in space group P21/c, with a = 10.3600(13) Å, b = 12.5650(16) Å, c = 9.9853(12) Å, and β = 103.599(2)°. Compound 1 crystallizes in a typical inorganic–organic layered structure adopted by metal naphthalenesulfonate, while compounds 2–4 crystallize in a hybrid inorganic–organic pattern. Unlike their Cu2+ analogue, the sulfonate does not coordinate directly to Ni2+. The hydrogen bonds formed between sulfonate and water molecules are the predominant packing forces for all structures. The inherited inversion center of the 1,5nds anion is carried into the crystal structure and results in centrosymmetric crystallization of all compounds.

Synthesis and characterization of bionanocomposites of poly(lactic acid) and TiO2 nanowires by in situ polymerization

Abstract Three silver(I) complexes containing pyridine derivatives have been synthesized and structurally characterized by X-ray single crystal diffraction, in order to evaluate the effect of counter anions upon the assembly process of complex cations via intermolecular hydrogen bonds. [Ag(nia) 2 ] 2 (bpds)·2H 2 O ( 1 ) and [Ag(nia) 2 ](asa) ( 2 ) (nia=nicotinamide, bpds=4,4′-biphenyldisulfonate, asa=aminosulfonate) contain cationic complexes comprised of two nicotinamide ligands coordinated with the pyridine nitrogen atoms to a silver(I) ion in a linear fashion. The linear unit is connected to another one by a weak AgAg interaction leading to an H-shaped dimeric unit. The dimeric units are linked through hydrogen bonds formed between amide groups in a head-to-head mode, creating one-dimensional cationic ribbons. In 1 , the ribbons are extended into two-dimensional network via hydrogen bonds formed by the amide groups. The cationic complex cations in [Ag(niac) 2 ] 2 (1,5nds)·2H 2 O ( 3 ) (niac=nicotinic acid, 1,5nds=1,5-disulfonate) are also connected to each other through AgAg interactions, leading to H-shaped dimeric units. The dimeric units are propagated via CH⋯O hydrogen bonds between the aromatic hydrogen atom and the carbonyl oxygen. A database search shows that the unique AgAg interaction between the discrete silver(I) coordinated linearly just by two pyridine nitrogen atoms is only observed in salts containing sulfonate or sulfate as counter anions.

Carbon nanotubes-supported PtAu-alloy nanoparticles for electro-oxidation of formic acid with remarkable activity

Abstract Crystal structures, absolute configurations, and crystalline packing features of nine complexes, namely, cis-α-Λ-(RR)(δλδ)-[Co(trien)(D-histidinato)](ClO4)2·2H2O 1, cis-β1-Δ-(RR)(λδδ)- [Co(trien)(L-asparaginato)](ClO4)2 2, cis-β2-Λ(SS)(λλδ)-[Co(trien)(L-valinato)](ClO4)2·H2O 3, cis-β2-Δ-(RR)(δδλ)[Co(trien)(D-methioninato)](ClO4)2 and its enantiomer 4, trans(N,t-N)-[Co(tren)(DL-leucinato)]X2, (X=ClO4− 5, BF4− 6, PF6− 7), and trans(N,t-N)-[Co(tren)(DL- methioninato)]X2 (X=Br− 8, Cl−(BF4−) 9) (trien=triethylenetetramine, tren=tris(2-aminoethyl)amine), have been determined. All compounds were prepared from racemic DL-amino acid. 1–3 crystallize as conglomerates. 5–7 are isomorphous and crystallize as the so-called conglomeratic solids. While 4, 8 and 9 undergo racemic crystallization. In 1–7, the carboxylic oxygen of the amino acid forms double hydrogen bonds with the amino hydrogen atoms of N4 and/or amino acidato of an adjacent cation. By these hydrogen bonds, cations having the same chirality are linked together into helical string. In the isomorphous 8 and 9, the cation containing L-methionine interacts with a cation containing D-methioninine, through hydrogen bonds, to form a racemic pair, and no spiral string arrangements are observed.