Ze-Bao Zheng

Synthesis and crystal structures of Cd(II), Ni(II), and Mn(II) complexes of 1H-benzotriazole-1-acetic acid

Three new complexes: [Cd(btaa)(bipy)(CH3COO) · H2O] n (1), [Ni(btaa)2(H2O)4 · 6H2O] n (2), and [Mn(btaa)2(H2O)2] n (3) (bipy = 2,2′-bipyridine, Hbtaa = 1H-benzotriazole-1-acetic acid) were prepared and characterized by IR, elemental analyses, thermogravimetric analyses, and single-crystal X-ray analyses. In 1, cadmium ions are linked by btaa ligands into 1-D linear chains; the chains are extended into layers through C–H ··· O hydrogen bonds and π–π stacking interactions. Complex 2 is a mononuclear structure, extended to a 3-D network through multiple intermolecular hydrogen bonds. In 3, manganese is bridged by carboxylate groups of btaa in the syn–skew bidentate mode in two directions to form a 2-D grid-like framework with a (4, 4) topology. The solid-state fluorescence spectrum of 1 shows that the excitation peak is at 355 nm while the maximum emission peak is at 424 nm.

Synthesis and crystal structure of potassium and manganese complexes of 1,2,3-triazole-4,5-dicarboxylic acid

Three coordination compounds [K(H2TDA)H2O] n (1), [K(H2TDA)(H3TDA)2H2O] n (2), and Mn2(phen)2(HTDA)2(H2O)4 (3) have been synthesized and characterized structurally by X-ray diffraction, where H3TDA = 1,2,3-triazole-4,5-dicarboxylic acid and phen = 1,10-phenanthroline. Their solid-state structures have been characterized by elemental analysis and IR spectroscopy. In 1, a 3-D (4, 8)-connected metal-organic framework has been constructed using dinuclear potassium clusters as eight-connected nodes and the ligands as four-connected nodes; it represents the fluorite topology network. Compound 2 exhibits 1-D chains along c-axis, which are connected by strong hydrogen-bond interactions in 2-D layers; the layers are further stacked via hydrogen bonds in the b-direction. In 3, two neighboring Mn(II) ions are bridged by two 1,2,3-triazole-4,5-dicarboxylic groups, forming a binuclear structure, with Mn(II) ··· Mn(II) distance of 4.356 Å, which is further linked to generate a 2-D layer structure via interdimer hydrogen bonds. The fluorescence for these compounds was investigated.

(E)-N′-(4-Pyridylmethyl­ene)-2-(quinolin-8-yl­oxy)acetohydrazide sesquihydrate

In the title compound, C17H14N4O2·1.5H2O, the mean planes of the pyridine ring and quinoline group make a dihedral angle of 21.0 (2)°. One water molecule lies on a twofold rotation axis. The organic molecules and the three water molecules are linked into infinite chains by N—H⋯O, O—H⋯O and O—H⋯N hydrogen bonds.

2,6‐Dimethoxy‐4‐(5‐oxo‐2‐phenyl‐4,5‐dihydro‐1,3‐oxazol‐4‐ylidenemethyl)phenyl acetate

The title compound, C20H17NO6, was synthesized by the reaction of syringaldehyde with hippuric acid. The molecule adopts a Z configuration about the central olefinic bond. The two benzene rings and the oxazolone ring are almost coplanar. The crystal structure is stabilized by weak intermolecular C—H...O hydrogen bonds.

Synthesis and crystal structure of two lanthanide coordination compounds of 4-(quinolin-8-yloxy)butanoic acid

Two lanthanide coordination compounds, [La(QYBA)3H2O]2 · 2H2O (1) and [Eu(QYBA)3(phen)]2 · 2H2O (2), have been synthesized and characterized structurally by X-ray diffraction, where QYBA = 4-(quinolin-8-yloxy)butanoic acid and phen = 1,10-phenanthroline. Their solid-state structures have been characterized by elemental analysis and IR spectroscopy. Both form a dimeric molecular structure through bridging oxygen atoms of carboxylate groups and both are nine-coordinate. Adjacent dimers in 1 are interlinked by QYBA into an infinite chain structure, while the dimers in 2 are interlinked by hydrogen bonds and π–π stacking interactions into a two-dimensional network.

Diaqua­(2,6-dioxo-1,2,3,6-tetra­hydro­pyrimidin-3-ide-4-carboxyl­ato-κ2N3,O4)(1,10-phenanthroline-κ2N,N′)manganese(II)

The title compound, [Mn(C5H2N2O4)(C12H8N2)(H2O)2], was synthesized by the reaction of manganese(II) acetate and orotic acid in the presence of 1,10-phenanthroline. The crystal structure exhibits intermolecular N—H⋯O and O—H⋯O hydrogen bonds . The Mn coordination environment consists of an N3O3 donor set in an octahedral geometry.

Synthesis and Structure of the Potassium Salt with Monodeprotonated 1,2,3-Tri(ethoxycarbonylpropyl)- p-t-butylcalix(6)arene

Alkylation of p-t-butylcalix[6]arene with ethyl 4-bromobutanoate in the presence of K2CO3 results in a potassium salt of the monodeprotonated 1,2,3-tri(ethoxycarbonylpropyl)-p-t-butylcalix[6]arene in high yield. X-Ray crystallographic analysis shows that this compound exists as a double partial cone conformation. The potassium ion is positioned near the centre of the cavity of the macrocycle and binds to four phenolic oxygens. Close contacts between the potassium ion and phenyl rings observed in this compound are indicative of the presence of the cation–π interaction. The molecules are connected via intermolecular K+···O interactions into infinite chains.

(2E,6E)-2,6-Difurfurylidenecyclo-hexa-none.

The complete molecule of the title compound, C16H14O3, is generated by crystallographic mirror symmetry, with two C atoms and one O atom lying on the mirror plane. The molecule adopts an E configuration about the C=C bond and the dihedral angle between the furan rings is 16.1 (2)°.

Chlorido(5-formyl-2-hydroxy­phenyl-κC1)mercury(II)

In the planar (r.m.s. deviation = 0.027 Å) title compound, [Hg(C7H5O2)Cl], the HgII atom shows a typical linear coordination by a C atom of the benzene ring and a Cl atom. Intermolecular O—H⋯O hydrogen bonds are present in the crystal structure, resulting in chains propagating along the b axis. The crystal studied was a non-merohedral twin, with a twin ratio of 0.802 (2):0.198 (2).

[2,6-Dioxo-1,2,3,6-tetra­hydro­pyrim­idine-4-carboxyl­ato(2−)]bis(pyrazino[2,3-f][1,10]phenanthroline)cobalt(II) dihydrate

The title complex, [Co(C5H2N2O4)(C14H8N4)2]·2H2O, features a slightly distorted octahedral geometry for Co due to the sterical requirements of the orotic acid and pyrazino[2,3-f][1,10]phenanthroline ligands. Intermolecular hydrogen bonding between the uncoordinated water molecules and the ligand stablizes the structure of the complex.