Synthesis And Characterization Of Novel Zinc Phosphite

Inorganic microporous crystal materials have not only the potential applications incatalysis, ion exchange, absorption, molecular recognization, ion conductor,magnetic field, but also have great significance in crystallography and the study ofbiomineralization. For the past decades, people have been interested in synthesis and application oftransition metal phosphate with open framework. And as we know, the structure ofHPO3 is similar to that of PO4 , so HPO3 may act as the structure unit to build 2- 3- 2-the open framework. Compared with the research on transition metal phosphate withopen framework, the research on transition metal phosphate templated by organicamine is rare. So, in the past few years, people have become interested in theresearch on transition metal phosphite. Up to now, a lot of phosphite compounds withopen framework have been synthesized, such as vanadium phosphite, chromiumphosphite, manganese phosphite, iron phosphite, cobalt phosphite and zincphosphite. Up to now, zinc phosphite play an important role among transition metal phosphite,since decades of zinc phosphite have been synthesized. Our work focuses on synthesis and characterization of new transition metalphosphite with open framework, and we have studied the condition to synthesizemetal phosphite, made an analysis to the factor which affect the synthesis, discussedgrow rule of the metal phosphite crystal under hydrothermal synthesis and describedin detail the structure of the crystals which were synthesized by us. A novel zinc phosphite (C4H8N2H4) [Zn(HPO3)2] has been synthesized by 56吉林大学硕士学位论文hydrothermal synthesis. The crystallographic data of the compound is a =17.748(2)?, b = 7.2428(9)?, c = 8.8087(11)?, β = 105.345(3)o, V=1091.9(2)?3,space group: Monoclinic, C2/c, Z=4. For this compound, each asymmetric unitcontains 8 non-hydrogen atoms, (1 Zn atom, 1 P atom, 3 O atoms, two C atoms and 1N atom). Each zinc center adopts typical a tetrahedral coordination geometry, withfour oxygen atoms occupying each coordination site. P center adopts pseudo pyramid.Of the three O atoms, two as bridge O connect with Zn and one is terminal O. The 1D chain framework structure of [Zn2(HPO3)3]2- is built from the strictly alternatingZnO4 tetrahedron and HPO3 pseudo pyramid that are linked through their vertices.The ethylenediammonium counter ions interact with the inorganic layers through O(inorganic layer)-H-N (counter ion) hydrogen bonds. All the N-H bonds of thecounter ions involved in the hydrogen bonds with the terminal oxygen atoms form akind of 3D structure. Still we have synthesized a novel zinc phosphite with 2D layer structure bysolvothermal synthesis. Crystal data: triclinic, space group P-1, a = 8.6501(5)?, b =8.8429(7)?, c = 9.9827(7)?, α = 64.541(3)°, β?= 65.891(3)°, γ= 81.001(4)°, Z= 2.For this compound, each asymmetric unit contains 18 non-hydrogen atoms, of which14 belong to the 'framework' and 4 to the 'guest' molecule. Each zinc center adoptstypical a tetrahedral coordination geometry, with four oxygen atoms occupying eachcoordination site. There are three crystallographically distinct P atoms. Of threephosphorus atoms, P(1) and P(3) make three P-O-Zn bonds and a P-H bond, whileP(2) makes two P-O-Zn bonds and one P-H bond and possesses a terminal O. Theframework structure of [Zn2(HPO3)3]2- is built from the strictly alternating ZnO4tetrahedron and HPO3 pseudo pyramid that are linked through their vertices. Theconnection between these tetrahedron and pseudo pyramid results in four-membered 57rings. While these four-membered rings are then connected to form a zigzagladder-like chain, furthermore, two or more such chains are connected via P(2) atomsto form a layer with an eight-membered aperture. The 2D [Zn2(HPO3)3]2- inorganiclayers stack with the ethylenediammonium co...