CN102180896B

CN102180896B - Chiral zinc complex secondary structure hollow microsphere and preparation method thereof

Info

Publication number: CN102180896B
Application number: CN 201110080809
Authority: CN
Inventors: 程鹏; 殷艳艳
Original assignee: Nankai University
Current assignee: Nankai University
Priority date: 2011-04-01
Filing date: 2011-04-01
Publication date: 2013-07-10
Anticipated expiration: 2031-04-01
Also published as: CN102180896A

Abstract

The invention discloses a chiral zinc complex secondary structure hollow microsphere. The chemical formula of the microsphere is shown as ([ZnL(H2O)].0.5H2O) infinite, wherein L is 2,4-thiazolidine diacid anion; a zinc complex belongs to a tetragonal system, has a three-dimensional network structure and is formed by assembling ZnNO5 modules; the coordination geometric configuration of zinc ions is a deformed octahedron; and adjacent zinc ions are bridged through carboxyl to constitute a three-dimensional metal organic frame structure. In the preparation method, zinc acetate and H2L are taken as raw materials, water is taken as a solvent, PVP (Polyvinyl Pyrrolidone) is taken as a surfactant and acetone is taken as a precipitant. The invention has the advantages that: the chiral zinc complex secondary structure hollow microsphere represents stronger negative Cotton effect and larger specific surface area and has wide application prospect as a novel functional material; the preparation method is easy to operate and has low cost; the obtained product has a regular shape and high stability; and a new measure is explored for the introduction of a novel material.

Description

A kind of chiral zinc title complex secondary is constructed tiny balloon and preparation method thereof

Technical field

The present invention relates to functional coordination polymer material, relate in particular to a kind of chiral zinc title complex secondary and construct tiny balloon and preparation method thereof.

Background technology

Hollow ball is the exotic materials that a kind of kernel has air or solvent composition, and the characteristics of its low density and high-ratio surface make it have good penetration, adsorptivity, screening molecule ability and optical property.This material hollow space can hold a large amount of guest molecules or large size object, thereby makes tiny balloon be applied to catalysis, chromatogram, drug controlled release system as a kind of novel functionalization material.Present most of tiny balloon is based on inorganics such as Cu ₂O synthesizes, and a metal-organic complex demonstrates such as peculiar properties such as chirality, magnetic because of comprehensive organic and inorganic two kinds of components.

Micrometre hollow sphere has feature such as low density, high-specific surface area, low thermal coefficient of expansion and ground specific refractory power, these character make it be widely used in support of the catalyst, the radioprotective skin-material, fields such as rechargeable cell also are subjected to scientist's extensive concern (F. Caruso, R. A. Caruso, H. M hwald, Science, 1998,282,1111-1114).The internal space that this material is abundant very likely is encapsulated in multifunctional material the internal space of this material, makes it accurately control chemical reaction, such as microreactor.In recent years, the material of synthetic hollow ball mainly concentrates on pure inorganic materials such as zinc oxide, cupric oxide etc., it is used at self be restricted.And functional ligand polymer makes its both satisfactory stability of organic and/or inorganic materials owing to the advantage of concentrating inorganic organic materials, and mechanicalness has the structure diversity, plasticity-of organic materials etc. again.If the tiny balloon of synthetic compound material will be concentrated the character of hollow ball and hybrid material, show the characteristic that simple inorganic hollow ball or title complex bulk-shaped monocrystal are not had.People are very ripe to the research of hollow ball in recent years, and the research of functional title complex tiny balloon still is in the blank stage at home and abroad.

Summary of the invention

The objective of the invention is at above-mentioned technical Analysis, a kind of method of utilizing microemulsion method synthesis of chiral Zn complex secondary to construct tiny balloon is provided, this material has negative section (Cotton) effect of pausing by circular dichroism test, and higher specific surface area is arranged, make it have potential using value aspect chirality and the gas adsorption as molecular material.

Technical scheme of the present invention:

A kind of chiral zinc title complex secondary is constructed tiny balloon, and this Zn complex chemical formula is { [ZnL (H ₂O)] 0.5H ₂O} _∞, L is 2,4-thiazolidine, two acid anions in the formula; This Zn complex belongs to tetragonal system, and spacer is P4 ₁, unit cell parameters is: a=12.343, b=12.343, c=5.3097, and α=90 °, β=90 °, γ=90 °; This Zn complex is three-dimensional net structure, by ZnNO ₅Module assembles, and the coordination geometric configuration of zine ion is octahedra for distortion, and each zine ion connects three parts, each part connects three zine ions simultaneously, adjacent zine ion is built into the 3-dimensional metal organic framework by the carboxyl bridging, and the coordination mode of L negatively charged ion is:

Figure 2011100808096100002DEST_PATH_IMAGE001

。

The preparation method that a kind of chiral zinc title complex secondary is constructed tiny balloon is with zinc acetate [Zn (CH ₃COO) ₂2H ₂O] and 2,4-thiazolidine diacid (H ₂L) being raw material, is solvent with water, and (PVP) is tensio-active agent with polyvinylpyrrolidone, is precipitation agent with acetone, comprises being prepared as follows step:

1) makes mixed solution in the water with being scattered in after zinc acetate and the polyvinylpyrrolidone mixing;

2) 2,4-thiazolidine, two aqueous acids are joined in the above-mentioned mixed solution, stirring at room 2 hours left standstill 4-8 hour under 80 ℃ of conditions;

3) generate white depositions behind the adding acetone, the centrifugal throw out that obtains absolute ethanol washing 10-20 time, the white powder thing that obtains is target product.

The mass ratio of described zinc acetate, polyvinylpyrrolidone and water is 1:23-27:300-400.

Described 2, the concentration of 4-thiazolidine two aqueous acids is 50 mmol/L, and the volume ratio of 2,4-thiazolidine, two aqueous acids and step 1 mixed solution is 1: 3.5-4.5.

The volume ratio of described acetone and reaction solution is 2-3: 1.

Advantage of the present invention and positively effect :The chiral coordination compound nanometer rod secondary of the present invention's preparation is constructed tiny balloon, show pause (cotton) effect and nanometer rod secondary of the stronger negative section of chiral material itself and construct the higher specific surface area that hollow ball has, make tiny balloon have broad application prospects as a kind of novel functionalization material.The present invention is simple to operate, and is with low cost, and the product pattern rule that obtains, and has satisfactory stability.Synthetic expansion and synthetic being significant for hollow ball material of this title complex tiny balloon have been opened up a new approach such as chirality to hollow ball material for introducing various new character later on simultaneously.

Description of drawings

Fig. 1 is the SEM image of chiral zinc title complex tiny balloon, and illustration is the microballoon enlarged view.

Fig. 2 be chiral zinc title complex tiny balloon in the circular dichroism test pattern.

Fig. 3 is the TG curve of chiral zinc title complex tiny balloon.

Fig. 4 is the nitrogen adsorption curve of chiral zinc title complex tiny balloon, and illustration is this material graph of pore diameter distribution.

Embodiment

Embodiment:

The present invention is with zinc acetate (Zn (CH ₃COO) ₂2H ₂O) and 2,4-thiazolidine diacid (H ₂L) being raw material, is solvent with water, and (PVP) is tensio-active agent with polyvinylpyrrolidone, is precipitation agent with acetone, is the commercially available prod, and with before need not to carry out any processing, preparation process is as follows:

1) with 0.44 g Zn (CH ₃COO) ₂2H ₂Be scattered in 160.0 g water after O and 11.20 g PVP mix and make mixed solution, its mass ratio is 1: 25.5:363.6;

2) with concentration be 50 mmol/L H ₂The H of O ₂The L aqueous solution 40.0 ml join in the above-mentioned mixed solution, and stirring at room 2 hours left standstill 6 hours under 80 ℃ of conditions;

3) white depositions occurs behind the adding acetone, the centrifugal throw out that obtains absolute ethanol washing 10 times obtain white powder and are target product.

The structure of this tiny balloon and property representation are measured:

1) testing tool of crystal morphology mensuration employing is HITACHI, S-3500N type scanning electronic microscope.As shown in Figure 1, can find out obviously that this hollow ball diameter is 5 microns on scheming, the pattern rule is evenly distributed, the tiny balloon that visible this complexes micro-sphere is constructed for the nanometer rod secondary from illustration.

2) title complex circular dichroism is measured and is adopted JASCO J-715 circular dichroism spectrometer, and pressing potassium bromide troche, probe temperature are room temperature.As Fig. 2, as seen this material has negative section (Cotton) effect of pausing, and shows tangible chirality feature.

3) NETZSCH TG 209 thermogravimetric analyzers are adopted in thermogravimetric test, heat up with 10 degrees centigrade of speed of per minute in nitrogen atmosphere, and as seen, this material is highly stable before 270 degrees centigrade, spends the sign that decomposition is just arranged up to 270 from Fig. 3.

4) specific surface area adopts ASAP 2010 micropore analysers, at first 100 degrees centigrade of vacuum outgass 10 hours, under liquid nitrogen temperature, measure adsorption curve and desorption curve then, and be 50.40 meters squared per gram according to the size that correlation data calculation obtains specific surface, this title complex hollow ball mean pore size is 11.6 nanometers as can be seen from Fig. 4.

Claims

1. a chiral zinc title complex secondary is constructed tiny balloon, it is characterized in that: this Zn complex chemical formula is { [ZnL (H ₂O)] 0.5H ₂O} _∞, L is 2,4-thiazolidine, two acid anions in the formula; This Zn complex belongs to tetragonal system, and spacer is P4 ₁, unit cell parameters is:

α=90 °, β=90 °, γ=90 °; This Zn complex is three-dimensional net structure, by ZnNO ₅Module assembles, and the coordination geometric configuration of zine ion is octahedra for distortion, and each zine ion connects three parts, each part connects three zine ions simultaneously, adjacent zine ion is built into the 3-dimensional metal organic framework by the carboxyl bridging, and the coordination mode of L negatively charged ion is:

2. the chiral zinc title complex secondary preparation method that constructs tiny balloon according to claim 1 is characterized in that: with the hydrate Zn (CH of zinc acetate ₃COO) ₂2H ₂O and 2,4-thiazolidine diacid are raw material, are solvent with water, and (PVP) is tensio-active agent with polyvinylpyrrolidone, are precipitation agent with acetone, comprise being prepared as follows step:

2) 2,4-thiazolidine, two aqueous acids are joined in the above-mentioned mixed solution, stirring at room 2 hours left standstill 4-8 hour under 80 ℃ of conditions, obtained reaction solution;

3. the preparation method who constructs tiny balloon according to the described chiral zinc title complex of claim 2 secondary, it is characterized in that: the mass ratio of described zinc acetate, polyvinylpyrrolidone and water is 1:23-27:300-400.

4. the preparation method who constructs tiny balloon according to the described chiral zinc title complex of claim 2 secondary, it is characterized in that: described 2, the concentration of 4-thiazolidine two aqueous acids is 50mmol/L, and the volume ratio of 2,4-thiazolidine, two aqueous acids and step 1 mixed solution is 1:3.5-4.5.

5. the preparation method who constructs tiny balloon according to the described chiral zinc title complex of claim 2 secondary is characterized in that: described acetone and step 2) volume ratio of reaction solution is 2-3:1.