ABSTRACT
The title compound, {[Ag(C6H7AsNO3)(C18H15P)]·H2O}n, has been synthesized from the reaction of 4-aminophenylarsonic acid with silver nitrate, in aqueous ammonia, with the addition of triphenylphosphane (PPh3). The Ag(I) centre is four-coordinated by one amino N atom, one PPh3 P atom and two arsonate O atoms, forming a severely distorted [AgNPO2] tetrahedron. Two Ag(I)-centred tetrahedra are held together to produce a dinuclear [Ag2O2N2P2] unit by sharing an O-O edge. 4-Aminophenylarsonate (Hapa(-)) adopts a µ3-κ(3)N:O:O-tridentate coordination mode connecting two dinuclear units, resulting in a neutral [Ag(Hapa)(PPh3)]n layer lying parallel to the (101Ì) plane. The PPh3 ligands are suspended on both sides of the [Ag(Hapa)(PPh3)]n layer, displaying up and down orientations. There is an R2(2)(8) hydrogen-bonded dimer involving two arsonate groups from two Hapa(-) ligands related by a centre of inversion. Additionally, there are hydrogen-bonding interactions involving the solvent water molecules and the arsonate and amine groups of the Hapa(-) ligands, and weak π-π stacking interactions within the [Ag(Hapa)(PPh3)]n layer. These two-dimensional layers are further assembled by weak van der Waals interactions to form the final architecture.
ABSTRACT
The title compound, {[Zn4(C8H4O4)3(OH)2(C12H6N2O2)2]·2H2O}n, has been prepared hydrothermally by the reaction of Zn(NO3)2·6H2O with benzene-1,4-dicarboxylic acid (H2bdc) and 1,10-phenanthroline-5,6-dione (pdon) in H2O. In the crystal structure, a tetranuclear Zn4(OH)2 fragment is located on a crystallographic inversion centre which relates two subunits, each containing a [ZnN2O4] octahedron and a [ZnO4] tetrahedron bridged by a µ3-OH group. The pdon ligand chelates to zinc through its two N atoms to form part of the [ZnN2O4] octahedron. The two crystallographically independent bdc(2-) ligands are fully deprotonated and adopt µ3-κO:κO':κO'' and µ4-κO:κO':κO'':κO''' coordination modes, bridging three or four Zn(II) cations, respectively, from two Zn4(OH)2 units. The Zn4(OH)2 fragment connects six neighbouring tetranuclear units through four µ3-bdc(2-) and two µ4-bdc(2-) ligands, forming a three-dimensional framework with uninodal 6-connected α-Po topology, in which the tetranuclear Zn4(OH)2 units are considered as 6-connected nodes and the bdc(2-) ligands act as linkers. The uncoordinated water molecules are located on opposite sides of the Zn4(OH)2 unit and are connected to it through hydrogen-bonding interactions involving hydroxide and carboxylate groups. The structure is further stabilized by extensive π-π interactions between the pdon and µ4-bdc(2-) ligands.
ABSTRACT
OBJECTIVE: To build a new processing procedure for Croton tiglium, providing a more simple, efficient and safe way of processing. METHODS: Used the contents of isoguanosine and toxic protein in Croton tiglium as the indexes to investigate the effect of different temperature, thickness and baked time on processing for Croton tiglium. After established all factors and levels, processed a batch of Croton tiglium under optimum processing conditions and compared it with raw Croton tiglium in the test of acute toxicity and gastrointestinal propulsive motility. RESULTS: The parameters of optimum processing were as follows:the temperature was set at 180 degrees C, the thickness of placement was 3 cm and baked time was 90 min. The LD50 value of raw Croton tiglium and the processed Croton tiglium was 888 mg/kg and 2139 mg/kg respectively. CONCLUSION: The processing procedure is simple, affordable, safe and efficient, deserved to promote for application.
