CN103833793A - Nickel-coordination polymer and preparation method thereof - Google Patents

Abstract

The invention relates to a nickel-coordination polymer and a preparation method thereof. molecular formula of the complex is represented as {[Ni2(BPTC) (1,4-bib)2(H2O)]2}}n, wherein H4BPTC is 3,4,3',4'-biphenyl tetracarboxylic acid and 1,4-bib is 1,4-bisimidazolyl benzene. The preparation method of the complex comprises the steps of mixing the H4BPTC, the 1,4-bib and Ni(NO3)2.6H2O in water at a certain proportion, regulating pH value to 6.5, adding a mixing liquid in a 13ml polytetrafluoroethylene tube, stirring for 30min at room temperature, sealing the polytetrafluoroethylene tube in a stainless steel reaction kettle, crystallizing for 72 hours at 160 DEG C, naturally cooling to room temperature to separate out light blue granular crystals, washing the crystals through distilled water and pumping the crystals through a vacuum pump, wherein yield is above 78%. The complex, through nickel dimer units in the structure and weak ferromagnetic action between dimer metallic nickel ions, can serve as a molecular magnetic material.

Description

A kind of nickel ligand polymer and preparation method thereof

Technical field

The present invention relates to nickel complex, be specifically related to a kind of nickel ligand polymer, particularly a kind of based on nickel (II) ion, 3,4,3', what 4'-biphenyltetracarboxyacid acid and Isosorbide-5-Nitrae-diimidazole benzene were constructed has nickel ligand polymer of weak ferromagnetic interaction and preparation method thereof.

Background technology

Molecular magnetic materials is not only a kind of novel functional materials, and relates to the frontier of the cross disciplines such as chemistry, physics, Materials science and life science.Traditional magneticsubstance is due to must be through pyrotic smelting, and density is large, precision sizing difficult forming, and the reason such as magnetic loss is large, is limited by very large in the application aspect such as new and high technology and hard-core technology.Than traditional magnetic material, molecular magnet is because of the diversity of its structure species, prepared by available low temperature method synthetic and processing, the over-all properties that can be combined with the aspect such as mechanical, optical, electrical, the features such as magnetic loss is little, need the field of light magnetic material to have very large application prospect in ultra-high frequency device, high-density storing material, absorbing material, microelectronics industry and aerospace etc., and have its unique advantage aspect corresponding in miniaturization, less energy-consumption, the high speed of device, the biological consistency connecting.Just because of this, how building the molecular magnet that can produce magnetic order within the scope of significant temp and be one of challenge that molecule magnetics and material science face, is also the important content of molecule magnetics research.

Summary of the invention

Object of the present invention, just based on the above-mentioned state of the art, provides a kind of nickel ligand polymer that can be used as molecular magnetic materials and preparation method thereof.

A kind of nickel ligand polymer provided by the invention, molecular formula is: { [Ni ₂(BPTC) (Isosorbide-5-Nitrae-bib) ₂(H ₂o) ₂] n, wherein H ₄bPTC is 3,4,3', 4'-biphenyltetracarboxyacid acid, and Isosorbide-5-Nitrae-bib is Isosorbide-5-Nitrae-diimidazole benzene.Its structural formula is:

The crystal of this title complex belongs to triclinic(crystalline)system, and spacer is P-1, and unit cell parameters is: a=8.1587 (9)

b=9.3411 (12)

c=12.7338 (12)

α=105.254 (2) °, β=98.139 (2) °, γ=107.777 (2) °.This title complex is double-core nickel octahedral coordination environment.Ni1 respectively with two different carboxylic acids in three O atoms, two N atoms, and a water molecules coordination; Ni2 respectively with two different carboxylic acids in O atom, a N atom, a water molecules, and an abutment phenol O Atomic coordinate.Ni-O bond distance's scope is 2.038 (4)-2.133 (3)

ni-N bond distance's scope is 2.081 (4)-2.090 (4) ni1-O1-Ni2 bond angle is 100.50 (14) °, and the distance between double-core Ni1 and Ni2 is 3.229

x-ray powder diffraction confirms crystal prototype stable homogeneous.

The preparation method of a kind of nickel ligand polymer provided by the invention, comprises the steps:

(1) by mol ratio be 3,4 of 1 ︰ 2 ︰ 2 ︰ 3800,3', 4'-biphenyltetracarboxyacid acid, Isosorbide-5-Nitrae-diimidazole benzene, Ni (NO ₃) ₂6H ₂o and water mix, and adjusting pH is 6.5, is placed in polyfluortetraethylene pipe;

(2) at least 20min of stirring at room temperature, is sealed in this polyfluortetraethylene pipe in stainless steel cauldron, and at 160 ℃, crystallization 72h, naturally cools to room temperature, separates out light blue particulate state crystal, drains collection product with distilled water wash final vacuum pump.

Draw polymkeric substance by matching alternating temperature susceptibility experimental data under 1000Oe foreign field in, between nickel ion, there is weak ferromagnetic interaction, can be used as molecular magnetic materials.

Advantage of the present invention and effect:

Nickel ligand polymer of the present invention is to obtain under hydrothermal synthesizing condition, and preparation method's technique is simple, and sample purity is high, and yield is high.Thermogravimetric analysis shows that its main structure decomposes more than 263 ℃, has higher thermostability.

Nickel ligand polymer provided by the invention is based on 3,4,3', 4'-biphenyltetracarboxyacid acid part and assistant ligand 1,4-diimidazole benzene is constructed, draw polymkeric substance by alternating temperature susceptibility experimental data under 1000Oe foreign field in, between nickel ion, there is weak ferromagnetic interaction, can be used as molecular magnetic materials.

Accompanying drawing explanation

The crystalline structure figure of Fig. 1 nickel ligand polymer of the present invention

Fig. 2 nickel ligand polymer of the present invention is at the X-ray powder diffraction figure of 298K

The thermogravimetric analysis figure of Fig. 3 nickel ligand polymer of the present invention

The alternating temperature susceptibility curve figure of Fig. 4 nickel ligand polymer of the present invention under 1000Oe external magnetic field

Embodiment

Embodiment 1. is by 0.1 mmole H ₄bPTC, the Ni (NO of the Isosorbide-5-Nitrae-bib of 0.2 mmole and 0.2 mmole ₃) ₂6H ₂o mixed dissolution is in 7mL water, adjusting pH is 6.5, be placed in 13ml polyfluortetraethylene pipe, stirring at room temperature 30min, is sealed in this polyfluortetraethylene pipe in stainless steel cauldron, crystallization 72h at 160 ℃, naturally cool to room temperature, separate out light blue particulate state crystal, drain collection product with distilled water wash final vacuum pump, productive rate is 78.2%.

The structure determination of nickel ligand polymer:

Crystal structure determination adopts Bruker Apex type X-ray single crystal diffractometer, uses Mo-K alpha-ray (λ=0.71073 through graphite monochromatization

) be incident radiation, collect point diffraction with ω-φ scan mode, obtain unit cell parameters through least-squares refinement, utilize SHELXL-97 direct method to solve crystalline structure from difference Fourier electron density map, and through Lorentz and polarizing effect correction.C atom adopts theoretical hydrogenation, and the hydrogen in water molecules on O atom provides by difference Fourier is synthetic,

and be fixed on parent atom.Detailed axonometry data are in table 1.Crystalline structure is shown in Fig. 1.

The crystallographic data of table 1 title complex

Powdery diffractometry:

X-ray powder diffraction result shows, crystal prototype thing phase homogeneous, and experiment diffracting spectrum, with consistent according to the powder diffraction spectrum of crystalline structure simulation, is shown in Fig. 2.

The thermogravimetric analysis of title complex:

Thermogravimetric analysis result shows that this polymkeric substance is weightless approximately 4.6% gradually between 200 ℃-263 ℃, illustrates and in polymkeric substance, deposits coordinated water (theoretical value 4.0%), and this result has further been proved the existence of water molecules in polymer crystals structure; Also can find out from thermogravimetric analysis Fig. 3 in addition, its agent structure is decomposed more than 263 ℃, illustrates that polymkeric substance has higher thermostability.

The magnetic property of nickel coordination polymer material:

Alternating temperature susceptibility curve as shown in Figure 4, as can be seen from the figure, χ when room temperature _mt value is 1.26cm ³kmol ^-1, lower than the be not coupled room temperature magnetic moment (2.0cm of Ni (II) ion of two independences ³k mol ^-1).Along with the reduction of temperature, χ _mt value slowly raises, and reaches maximum value 1.38cm in the time of 7K ³kmol ^-1, show that double-core nickel interionic exists local ferromagnetic interaction, the 1.00cm while being then down to 1.8K rapidly ³kmol ^-1.In addition, utilize Curie-Weiss law matching χ _m ^-1-T(Fig. 4 illustration), can obtain C=1.25cm ³mol ^-1,, in positive θ value proving again polymkeric substance, between nickel ion, there is weak ferromagnetic interaction in θ=0.61K.

Claims (3)

1. a nickel ligand polymer, is characterized in that, its structural formula is:

2. the preparation method of nickel ligand polymer as claimed in claim 1, is characterized in that, comprises the steps:

(1) by mol ratio be 3,4 of 1 ︰ 2 ︰ 2 ︰ 3800,3', 4'-biphenyltetracarboxyacid acid, Isosorbide-5-Nitrae-diimidazole benzene, Ni (NO ₃) ₂6H ₂o and water mix, and adjusting pH is 6.5, is placed in polyfluortetraethylene pipe;

(2) at least 20min of stirring at room temperature, is sealed in this polyfluortetraethylene pipe in stainless steel cauldron, and at 160 ℃, crystallization 72h, naturally cools to room temperature, separates out light blue particulate state crystal, drains collection product with distilled water wash final vacuum pump.

3. nickel ligand polymer as claimed in claim 1 is as molecular magnetic materials.

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