PHOTOINDUCED-NONLINEAR-EXPANSION COORDINATION POLYMER AND PREPARATION METHOD THEREOF

Abstract

The invention provides a photoinduced-nonlinear-expansion coordination polymer and preparation method thereof. The coordination polymer has a chemical formula of [Zn(iba)(tkpvb)Cl].sub.n1, wherein iba represents p-iodobenzoate, tkpvb represents 1,2,4,5-tetrakis((E)-2-(4-pyridyl)vinyl)benzene, and n=3000-60000; and crystallographic parameters of: (1) crystal system: monoclinic system; (2) space group: Cc; (3) a = 28.6156(16) Å, b = 7.2901(4) Å, c = 21.5157(13) Å, β = 127.430(4)°, and V = 3574.2(4) Å.sup.3; (4) Z = 4; and (5) F(000) = 1680, R.sub.1 = 0.1363, wR.sub.2 = 0.3788, and GOF = 1.620; wherein iba represents p-iodobenzoate, tkpvb represents 1,2,4,5-tetrakis((E)-2-(4-pyridyl)vinyl)benzene, and n1=3000-60000. The preparation method of the coordination polymer of the present invention is simple, and has mild reaction conditions, and fast light conversion rate. Moreover, the coordination polymer undergoes an addition reaction, exhibits the photoinduced nonlinear expansion performance of the material, and affords a corresponding isomeric compound under the irradiation of light of various wavelengths.

Claims

1. A photoinduced-nonlinear-expansion coordination polymer, wherein the coordination polymer is a bright yellow bulk crystal and has a chemical formula of [Zn(iba)(tkpvb)Cl].sub.n1 and crystallographic parameters of: (1) crystal system: monoclinic system; (2) space group: Cc; (3) a = 28.6156(16) Å, b = 7.2901(4) Å, c = 21.5157(13) Å, β = 127.430(4)°, and V = 3574.2(4) Å.sup.3; (4) Z = 4; and (5) F(000) = 1680, R.sub.1 = 0.1363, wR.sub.2 = 0.3788, and GOF= 1.620; wherein iba represents p-iodobenzoate, tkpvb represents 1,2,4,5-tetrakis((E)-2-(4-pyridyl)vinyl)benzene, and n1=3000-60000.

2. A method for preparing a photoinduced-nonlinear-expansion coordination polymer according to claim 1, comprising the following steps: dissolving zinc nitrate hexahydrate, p-iodobenzoic acid or a water-soluble salt thereof, and 1,2,4,5-tetrakis((E)-2-(4-pyridyl)vinyl)benzene in a mixed solvent of N,N′-dimethylformamide and water, adjusting the pH to 5-6, and reacting to obtain the photoinduced-nonlinear-expansion coordination polymer.

3. The preparation method according to claim 2, wherein the molar ratio of zinc nitrate hexahydrate, p-iodobenzoic acid or a water-soluble salt thereof and 1,2,4,5-tetrakis((E)-2-(4-pyridyl)vinyl)benzene is 1-2.5: 1-2.5: 1-2.5.

4. The preparation method according to claim 2, wherein the reaction temperature is 120 to -125° C., and the time is 5-12 h.

5. The preparation method according to claim 2, wherein the volume ratio of N,N′-dimethylformamide and water in the mixed solvent is 1:1-1:4.

6. An isomer of the photoinduced-nonlinear-expansion coordination polymer according to claim 1, wherein the isomer is obtained by irradiating the photoinduced-nonlinear-expansion coordination polymer with a light source having a wavelength of 365-500 nm.

7. The isomer according to claim 6, wherein the light source having a wavelength of 500 nm, 475 nm, 450 nm, 420 nm, 400 nm, 380 nm or 365 nm.

8. A method for preparing a polycyclobutane derivative, having a chemical formula shown by Formula (I): ##STR00004## wherein n2=3000-60000, the method comprising: irradiating the photoinduced-nonlinear-expansion coordination polymer according to claim 1 with a light source having a wavelength of 365-500 nm, to obtain a product A; and treating the product A with a strong acid, and then neutralizing, to obtain the polycyclobutane derivative.

9. The method for preparing a polycyclobutane derivative according to claim 8, wherein the strong acid is selected from the group consisting of concentrated hydrochloric acid, concentrated sulfuric acid, concentrated nitric acid and any combination thereof.

10. A polycyclobutane derivative prepared by the method according to claim 8.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0029] FIG. 1 is a schematic diagram showing the synthesis of Compound [Zn(iba)(tkpvb)Cl].sub.n1 in Example 1.

[0030] FIG. 2 shows the one-dimensional stacking of Compound [Zn(iba)(tkpvb)Cl].sub.n1 in Example 1.

[0031] FIG. 3 shows a X-ray powder diffraction pattern of Compound [Zn(iba)(tkpvb)Cl].sub.n1 in Example 1.

[0032] FIG. 4 shows a thermogravimetric analysis profile of Compound [Zn(iba)(tkpvb)Cl].sub.n1 in Example 1.

[0033] FIG. 5 shows a two-dimensional structure of Compound [Zn(iba)(poly-bpbpvpcb)Cl].sub.n3(Zn-2a) in Example 2.

[0034] FIG. 6 shows thermogravimetric analysis profile of Compound [Zn(iba)(poly-bpbpvpcb)Cl].sub.n3(Zn-2a) in Example 2.

[0035] FIG. 7 shows the photoinduced changes of the parameters a axis, b axis, c axis, and volume V of the unit cell in Example 9.

[0036] FIG. 8 shows the photoinduced changes of the pyridine ring and benzene ring in the tkpvb ligand in Example 9.

[0037] FIG. 9 shows the change in structure of the polycyclobutane derivative poly-bpbpvpcb formed in Example 9.

[0038] FIG. 10 is a schematic diagram showing the structure of the polycyclobutane derivative poly-bpbpvpcb in Example 10.

[0039] FIG. 11 shows a .sup.1H NMR spectrum of tkpvb in Example 10.

[0040] FIG. 12 shows a .sup.1H NMR spectrum of the polycyclobutane derative poly-bpbpvpcb in Example 10.

[0041] FIG. 13 shows a thermogravimetric analysis profile of the polycyclobutane derivative poly-bpbpvpcb in Example 10.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0042] The present invention will be further described below with reference to the accompanying drawings and specific examples, so that those skilled in the art can better understand and implement the present invention; however, the present invention is not limited thereto.

Example 1: Preparation of Coordination Polymer [Zn(iba)(tkpvb)Cl].SUB.n1

[0043] A mixture of zinc nitrate hexahydrate (297 mg, 0.1 mmol), 1,2,4,5 -tetrakis((E)-2-(4-pyridyl)vinyl)benzene (490 mg, 0.1 mmol) and p-iodobenzoic acid (248 mg, 0.1 mmol) was added to a 25 mL of thick-walled pressure flask. Then 10 mL of a mixed solution of N,N′-dimethyl formamide and deionized water at a volume ratio of 2:3 was added, and the system was adjusted to about pH 5 with 0.1 M hydrochloric acid. The flask was sealed, ultrasonically dispersed for 10 min, heated for 8 hrs in an oven at a temperature programmed to 120° C., and then naturally cooled to room temperature, to obtain a bright yellow lump crystal [Zn (iba)(tkpvb)Cl].sub.n1(Zn-1). The crystal was washed with ethanol, the collected, and dried in an oven at 60° C. Yield: 462.8 mg (65%, calculated based on 1,2,4,5-tetrakis((E)-2-(4-pyridyl)vinyl)benzene). Elemental analysis (%):C.sub.41H.sub.30CIIN.sub.4O.sub.2Zn; Calculated: C 58.73, H 3.61, N 6.68; Found: C 58.73 H 3.60, N 6.65.

[0044] Infrared spectrum (potassium bromide disc method): 3964 (w), 2648 (w), 1697 (w), 1415 (w), 1389 (s), 1304 (m), 1257 (s), 1195 (w), 914 (m), 748 (m) cm.sup.-1.

[0045] The structure of the compound was characterized by single crystal X-ray diffraction, powder X-ray diffraction and thermogravimetric analysis. The crystallographic parameters are listed in Table 1. The X-ray powder diffraction pattern and thermogravimetric analysis profile are shown in FIGS. 3 and 4.

TABLE-US-00001 Crystallographic parameters of the coordination polymer of Example 1 Compounds Zn—1 Molecular formula C.sub.41H.sub.30ClIN.sub.4O.sub.2Zn Molecular weight 838.42 Temperature 119.98 Crystal system Monoclinic Space group Cc a/Å 28.6156(16) b/Å 7.2901(4) c/Å 21.5757(13) α/° 90 β/° 127.430(4) γ/° 90 V/Å.sup.3 3574.2(4) Dc/g cm-3 1.558 Z 4 .Math. (Mo-Kα)/mm.sup.-1 1.668 Total number of diffraction points 23221 Number of independent diffraction points 7244 F(000) 1680 R.sub.1.sup.a 0.1363 wR.sub.2.sup.b 0.3788 GOF.sup.c 1.620

The compound is monoclinic, and the space group is Cc. FIGS. 1-2 schematically show the synthesis and the spatial structure of Compound Zn-1. As can be seen, the central metal ion in the above coordination polymer containing an alkene ligand is Zn.sup.2+, which is coordinated with O in one p-iodobenzoic acid molecule, Cl in hydrochloric acid and N in the two tkpvb ligand molecules. The metal ions are bridged by the tkpvb ligand, and extend to form a one-dimensional chain-like structure.

Example 2: Preparation of Coordination Polymer [Zn(iba)(poly-bpbpvpcb)Cl].SUB.n3.(Zn-2a)

[0046] At room temperature, a small amount of Zn-1 crystal was placed on a clean glass slide, and irradiated with an LED light having a wavelength of 365 nm for 30 min while a distance of 2 cm was maintained between the light source and the crystal to obtain a [2+2] cycloaddition product [Zn(iba)(poly-bpbpvpcb)Cl].sub.n3 (Zn-2a) with a conversion rate of 100%.

[0047] Elemental analysis (%): C.sub.41H.sub.30ClIN.sub.4O.sub.2Zn; Calculated: C 58.73, H 3.61, N 6.68; Found: C 58.77 H 3.59 N 6.66.

[0048] Infrared spectrum (potassium bromide disc method): 3440 (w), 3066 (w), 2938 (w), 2359 (w), 1938 (w), 1824 (w), 1640 (s), 1504 (m), 1393 (s), 1223 (w), 1032 (m), 919 (w), 881 (m), 821 (s), 745 (s), 688 (m), 546 (s) cm.sup.-1.

[0049] The product was tested by single crystal X-ray diffraction. The crystallographic parameters are listed in Table 2. The single crystal structure is shown in FIG. 5.

Example 3: Preparation of Coordination Polymer [Zn(iba)(poly-bpbpvpcb)Cl].SUB.n3.(Zn-2b)

[0050] At room temperature, a small amount of Zn-1 crystal was placed on a clean glass slide, and irradiated with an LED light having a wavelength of 385 nm for 30 min while a distance of 2 cm was maintained between the light source and the crystal to obtain a [2+2] cycloaddition product [Zn(iba)(poly-bpbpvpcb)Cl].sub.n3 (Zn-2b) with a conversion rate of 100%.

[0051] Elemental analysis (%): C.sub.41H.sub.30ClIN.sub.4O.sub.2Zn; Calculated: C 58.73, H 3.61, N 6.68; Found: C 58.73, H 3.63, N 6.64.

[0052] The product was tested by single crystal X-ray diffraction. The crystallographic parameters are listed in Table 2.

Example 4: Preparation of Coordination Polymer [Zn(iba)(poly-bpbpvpcb)Cl].SUB.n3 (Zn-2c)

[0053] At room temperature, a small amount of Zn-1 crystal was placed on a clean glass slide, and irradiated with an LED light having a wavelength of 400 nm for 30 min while a distance of 2 cm was maintained between the light source and the crystal to obtain a [2+2] cycloaddition product [Zn(iba)(poly-bpbpvpcb)Cl].sub.n3 (Zn-2c) with a conversion rate of 100%.

[0054] Elemental analysis (%): C.sub.41H.sub.30ClIN.sub.4O.sub.2Zn; Calculated: C 58.73, H 3.61, N 6.68; Found: C 58.70, H 3.52, N 6.67.

[0055] The product was tested by single crystal X-ray diffraction. The crystallographic parameters are listed in Table 2.

Example 5: Preparation of Coordination Polymer [Zn(iba)(poly-bpbpvpcb)Cl].SUB.n3 (Zn-2d)

[0056] At room temperature, a small amount of Zn-1 crystal was placed on a clean glass slide, and irradiated with an LED light having a wavelength of 420 nm for 30 min while a distance of 2 cm was maintained between the light source and the crystal to obtain a [2+2] cycloaddition product [Zn(iba)(poly-bpbpvpcb)Cl].sub.n3 (Zn-2d) with a conversion rate of 100%.

[0057] Elemental analysis (%): C.sub.41H.sub.30ClIN.sub.4O.sub.2Zn; Calculated: C 58.73, H 3.61, N 6.68; Found: C 58.77, H 3.69, N 6.65.

[0058] The product was tested by single crystal X-ray diffraction. The crystallographic parameters are listed in Table 2.

Example 6: Preparation of Coordination Polymer [Zn(iba)(poly-bpbpvpcb)Cl].SUB.n3 (Zn-2e)

[0059] At room temperature, a small amount of Zn-1 crystal was placed on a clean glass slide, and irradiated with an LED light having a wavelength of 450 nm for 30 min while a distance of 2 cm was maintained between the light source and the crystal to obtain a [2+2] cycloaddition product [Zn(iba)(poly-bpbpvpcb)Cl].sub.n3 (Zn-2e) with a conversion rate of 100%.

[0060] Elemental analysis (%): C.sub.41H.sub.30ClIN.sub.4O.sub.2Zn; Calculated: C 58.73, H 3.61, N 6.68; Found: C 58.74, H 3.64, N 6.69.

[0061] The product was tested by single crystal X-ray diffraction. The crystallographic parameters are listed in Table 2.

Example 7: Preparation of Coordination Polymer [Zn(iba)(poly-bpbpvpcb)Cl].SUB.n3 (Zn-2f)

[0062] At room temperature, a small amount of Zn-1 crystal was placed on a clean glass slide, and irradiated with an LED light having a wavelength of 475 nm for 30 min while a distance of 2 cm was maintained between the light source and the crystal to obtain a [2+2] cycloaddition product [Zn(iba)(poly-bpbpvpcb)Cl].sub.n3 (Zn-2f) with a conversion rate of 100%.

[0063] Elemental analysis (%): C.sub.41H.sub.30ClIN.sub.4O.sub.2Zn; Calculated: C 58.73, H 3.61, N 6.68; Found: C 58.77, H 3.55, N 6.68.

[0064] The product was tested by single crystal X-ray diffraction. The crystallographic parameters are listed in Table 2.

Example 8: Preparation of Coordination Polymer [Zn(iba)(poly-bpbpvpcb)Cl].SUB.n3 (Zn-2 g)

[0065] At room temperature, a small amount of Zn-1 crystal was placed on a clean glass slide, and irradiated with an LED light having a wavelength of 500 nm for 30 min while a distance of 2 cm was maintained between the light source and the crystal to obtain a [2+2] cycloaddition product [Zn(iba)(poly-bpbpvpcb)Cl].sub.n3 (Zn-2g) with a conversion rate of 100%.

[0066] Elemental analysis (%): C.sub.41H.sub.30ClIN.sub.4O.sub.2Zn; Calculated: C 58.73, H 3.61, N 6.68; Found: C58.71 H 3.64, N 6.66.

[0067] The products obtained in Examples 2 to 8 were tested by single crystal X-ray diffraction. The crystallographic parameters are listed in Table 2.

TABLE-US-00002 Crystallographic parameters of the coordination polymer of Examples 2 to 8 Compounds Zn-2a Zn-2b Zn-2c Zn-2d Molecular formula C.sub.41H.sub.30ClIN.sub.4O.sub.2Zn C.sub.41H.sub.30ClIN.sub.4O.sub.2Zn C.sub.41H.sub.30ClIN.sub.4O.sub.2Zn C.sub.41H.sub.30ClIN.sub.4O.sub.2Zn Molecular weight 838.41 838.41 838.41 838.41 Crystal system Monoclinic Monoclinic Monoclinic Monoclinic Space group Cc Cc Cc Cc a/Å 29.113(19) 29.144(3) 29.1283(19) 29.1610(17) b/Å 7.298(5) 7.2990(7) 7.3059(5) 7.3081(3) c/Å 21.452(13) 21.4760(18) 21.5428(14) 21.5547(12) α/° 90 90 90 90 β/° 127.257(11) 127.317(2) 127.360(2) 127.3910(10) γ/° 90 90 90 90 V/Å.sup.3 3628(4) 3633.2(6) 3643.9(4) 3649.6(3) Z 4 4 4 4 D.sub.c/(g cm.sup.-3) 1.535 1.533 1.525 1.526 .Math. (Mo-Kα)/mm.sup.-1 1.643 1.641 1.635 1.633 F(000) 1680 1680 1676 1680 Total number of diffraction points 25927 15217 47717 23605 Number of independent diffraction points 7465 6448 8436 5853 R.sub.int 0.0824 0.077 0.1049 0.0536 R.sub.1.sup.a 0.1021 0.1037 0.1773 0.1108 wR.sub.2.sup.b 0.2657 0.2695 0.4359 0.2938 GOF.sup.c 1.094 1.107 1.766 1.357

TABLE-US-00003 Compounds Zn-2e Zn-2f Zn-2g Molecular formula C.sub.41H.sub.30ClIN.sub.4O.sub.2Zn C.sub.41H.sub.30ClIN.sub.4O.sub.2Zn C.sub.41H.sub.30ClIN.sub.4O.sub.2Zn Molecular weight 838.41 838.41 838.41 Crystal system Monoclinic Monoclinic Monoclinic Space group Cc Cc Cc a/Å 29.199(11) 29.248 29.222(8) b/Å 7.321(3) 7.322 7.3096(19) c/Å 21.560(7) 21.53 21.520(6) α/° 90 90 90 β/° 127.283(13) 127.37 127.377(12) γ/° 90 90 90 V/Å.sup.3 3667(2) 3664.4 3652.8(18) Z 4 4 4 D.sub.c/(g cm.sup.-3) 1.519 1.52 1.525 .Math. (Mo-Kα)/mm.sup.-1 1.625 1.627 1.632 F(000) 1680 1680 1680 Total number of diffraction points 20847 66338 29005 Number of independent diffraction points 7786 8398 7410 R.sub.int 0.0635 0.0744 0.0566 R.sub.1.sup.a 0.0912 0.1044 0.11 wR.sub.2.sup.b 0.2356 0.2861 0.2909 GOF.sup.c 1.04 1.352 1.365

Example 9: Photo-Induced Nonlinear Expansion Behavior

[0068] The method was the same as that in Examples 2 to 8, where the coordination polymer from Example 1 was irradiated with light of various wavelengths (500 nm, 475 nm, 450 nm, 420 nm, 400 nm, 380 nm or 365 nm), to obtain a series of coordination polymers [Zn(iba)(/poly-bpbpvpcb)C1].sub.n3 (Zn-2n, n=a-g) capable of nonlinear expansion. Some unit cell parameters of these compounds exhibit a nonlinear expansion behavior. FIG. 8 schematically shows the photoinduced expansion.

[0069] As shown in FIG. 7, after being irradiated with light having a wavelength of 365 - 500 nm, the unit cell parameters of the crystals show different trends. The length of the b-axis of the unit cell remains basically unchanged; the length of the α-axis and c-axis of the unit cell and the unit cell volume V all show a nonlinear expansion trend; and under irradiation with light having a wavelength of 450 nm, the unit cell volume V reaches the maximum degree of expansion. The analysis of the single crystal structure by single crystal X-ray diffraction reveals that this photoinduced nonlinear expansion phenomenon is mainly attributed to the difference in the absorption and conversion of photons by the compound, causing the changes in the compound structure to different degrees after irradiation with light. The central benzene ring in tkpvb rotates clockwise or counterclockwise upon the photochemical reaction, leading to the rotation of the attached pyridine ring (see FIG. 8). Based on the experimental test data, the fitted Formulas (1), (2), and (3) are used to represents the relationships between the lengths of the α-axis and c-axis of the unit cell and the unit cell volume V and the wavelength (λ) of light for irradiation:

[00001]$a={\omega }_1+{\omega }_{2}x\exp \left(\text{-}0.5x{\left(\left(\lambda \text{-}{\omega }_4\right)/{\omega }_3\right)}^2\right)$

where the value of ω.sub.1, ω.sub.2, ω.sub.3 and ω.sub.4 are respectively 29.1367 Å, 0.1051 Å, 34.6278 nm.sup.2 and 479.3353 nm.

[00002]$c={\omega }_1+{\omega }_{2}x\exp \left(\text{-}0.5x{\left(\left(\lambda \text{-}{\omega }_4\right)/{\omega }_3\right)}^2\right)$

where the value of ω.sub.1, ω.sub.2, ω.sub.3 and ω.sub.4 are respectively -3338.8508 Å, 3360.4198 Å, 8721.2263 nm.sup.2 and 446.1376 nm.

[00003]$V={\omega }_1+{\omega }_{2}x\exp \left(\text{-}0.5x{\left(\left(\lambda \text{-}{\omega }_4\right)/{\omega }_3\right)}^2\right)$

where the value of ω.sub.1, ω.sub.2, ω.sub.3 and ω.sub.4 are respectively 3971.94 Å.sup.3, 147.31 Å.sup.3, 61.22 m.sup.2 and 438.46 nm.

Example 10: Synthesis and Characterization of Polycyclobutane Derivative Poly-bpbpvpcb

[0070] 200 mg of Compound Zn-2a was added to a flask, 10 mL of concentrated hydrochloric acid was added and stirred for 24 hrs, and then neutralized to pH=7 with 1 mol/L sodium hydroxide. 20 mL of dichloromethane was then added and stirred for 3 hrs. After rotary evaporation, poly-bpbpvpcb as a light yellow powder was obtained, with a yield of 92%. The .sup.1H NMR of poly-bpbpvpcb is shown in FIG. 13.

[0071] .sup.1H NMR (400 MHz, CDCl.sub.3): δ 8.65 (d, J= 4.0 Hz, 4H), 7.85 (s, 1H), 7.65 (d, J = 16.0 Hz, 2H), 7.42 (d, J = 8 Hz, 4H), 7.05 (d, J = 16.0 Hz, 2H), 5.35(d, J = 12.0 Hz, 2H). The poly-bpbpvpcb was tested by thermogravimetric analysis. The results are shown in FIG. 13. It can be seen that the material has good thermal stability below 800° C., and can be used as a new heat-resistant material.

[0072] Obviously, the above-described embodiments are merely examples provided for clarity of description, and are not intended to limit the implementations of the present invention. Other variations or changes can be made by those skilled in the art based on the above description. The embodiments are not exhaustive herein. Obvious variations or changes derived therefrom also fall within the protection scope of the present invention.