JPH0324462B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to 4,4'-bis(2''-norbornadienecarbonyloxy)benzophenone, which is a type of benzophenone derivative, a method for producing the same, and a light energy storage material using the same.

In recent years, research has been conducted from various fields on how to effectively utilize the solar energy that living things on earth enjoy. One such field is the conversion of light energy into chemical energy, and research is being conducted into using sunlight as light energy and storing this as chemical energy in a conversion agent. Here, the conversion of light energy into chemical energy means, for example, that sunlight is irradiated onto a chemical substance, and the chemical substance (represented by the symbol A, for example) is photoisomerized by the sunlight's light energy, and the chemical bond is Because it has a strain of
means to obtain as. The energy thus converted into chemical bond energy is released as heat when compound B is converted into the original compound A using appropriate means as needed. Therefore, this compound A functions as a light energy storage material.

As research from this point of view, for example, norbornadiene-quadricyclene system (compound A
Although norbornadiene is suitable for absorbing short-wavelength light in the ultraviolet region, it hardly absorbs near-ultraviolet light from the sun as it is, so it cannot be used with so-called sensitizers. Must be used in combination.

In addition, as an alternative to sensitizers to make it easier to absorb sunlight, a method of introducing functional groups into norbornadiene is known, but the production of such derivatives requires a long reaction process and is industrially difficult. It is hard to say that it is a practical method.

On the other hand, phototautomerization of cis-trans isomers of olefins is unsuitable for energy storage because a dark reaction from the cis to the trans isomer may occur.

In view of this point, the present inventors have conducted extensive research into optical energy storage materials that can easily absorb sunlight and withstand long-term storage, resulting in the present invention.

That is, the 4,4'-bis(2''-norbornadienecarbonyloxy)benzophenone of the present invention (abbreviated as the present compound) can easily absorb sunlight energy and cause a photoisomerization reaction. Since the sensitizing function part and the energy conversion function part are in the same molecule, there is almost no adverse effect from oxygen etc. during photoisomerization.Therefore, the photoisomerization rate is also extremely fast; for example, when a benzene solution is exposed to sunlight, By simply leaving it under the formula ()
is quantitatively converted to 4,4'-bis(1''-quadricyclenecarbonyloxy)benzophenone (hereinafter abbreviated as Q-form).

This Q-form does not change even after long-term storage, and can be returned to its original state by contacting it with AgBF ₄ , Rh(CO) ₄ Cl ₂ , metal voluphirins, etc., either in a solvent or without dissolving it in a solvent. Upon conversion to this compound, approximately 35 Kcal/mol of heat is generated. Moreover, the reconstituted compound can be used repeatedly. In this way, this compound can store light energy such as sunlight in the form of chemical energy, and this can be extracted at any time as thermal energy etc., making it a practical light energy storage material. It is something.

Next, the method for producing this compound will be described. This 4,4'-bis-(2''-norbornadienecarbonyloxy)benzophenone is 4,4'-dipropioloyloxybenzophenone obtained by condensing 4,4'-dihydroxybenzophenone with propiolic acid. Dales of cyclopentadiene
It can be produced by Alder reaction. This reaction is carried out in the presence of a solvent or in the absence of a solvent at -10°C to 100°C, preferably at 10°C to 30°C. When using a solvent, various ether-based, halogen-based, ester-based, and aromatic solvents can be used.

In addition, this 4,4'-bis(2''-norbornadienecarbonyloxy)benzophenone is 4,4'-
It can also be produced by condensation of dihydroxybenzophenone and 2-norbornadienecarboxylic acid. That is, 4,4'-dihydroxybenzophenone and 2-norbornadienecarboxylic acid are dissolved in an inert solvent such as an ether type, ester type, or aromatic type, and N,N'-dicyclohexylcarbodiimide is added thereto as a condensing agent. 0℃ to 80
It can be produced by reacting at 10°C to 40°C. The stoichiometric amount of N,N'-dicyclohexylcarbodiimide used in this case is sufficient.

EXAMPLES The present invention will be explained in more detail with reference to Examples below, but these Examples do not limit the present invention in any way.

Example 1 Dissolve 5.0 g of 4,4'-dipropioloyloxybenzophenone in 20 ml of ethyl acetate, and add 20
A solution of g of cyclopentadiene dissolved in 40 ml of benzene is added and stirred for 12 hours at room temperature under a nitrogen stream to form a white precipitate. This precipitate is filtered, washed with ethyl acetate, and dried. Yield 6.30g. This was recrystallized from methylene chloride and ethyl acetate,
6.10 g of 4,4'-bis(2''-norbornadienecarbonyloxy)benzophenone was obtained. Yield: 86.2
%. White crystal. Next, the physical properties are shown.

Melting point: Turns brown at around 270℃, but does not melt above 310℃. ¹ HNMR: (CD ₂ Cl ₂ ) δ value (ppm) 2.07-2.32 (m, 4H); 3.70-3.86 (m, 2H); 3.90-4.02 (m, 2H); 6.68-6.85 (m, 2H); 6.90-7.03 (m, 2H); 7.21 (d, 4H); 8.81 (d, 4H); ca.7.80-7.90 (2H) IR: (cm ^-1 ) KBr, 3002, 2950, 2900, 1730, 1650, 1595, 1414,
1290, 1205, 1160, 1145, 1050, 935, 888 UV: (acetonitrile) λmax (ε) = 268 (23800) Elemental analysis value, ( ) is calculated value C: 77.34% (77.32%); H: 4.91% (4.92%) Example 2 2.14g of 4,4'-dihydroxybenzophenone and 2.80g of 2-norbornadienecarboxylic acid
4.1 Dissolve in 100ml of tetrahydrofuran and cool on ice.
g of N,N'-cyclohexylcarbodiimide was added and stirred overnight. The resulting precipitate was removed by filtration, and the solution was concentrated. The residue after concentration was repeatedly recrystallized from a mixed solvent of methylene chloride and ethyl acetate to obtain 2.0 g of white crystals. Yield as target product
44.4%. The nuclear magnetic resonance spectrum and infrared absorption spectrum were the same as in Example 1, and it was identified as the target product.

Example 3 A benzene solution of 2.60×10 ^-3 mol/4,4′-bis(2″-norbornadienecarbonyloxy)benzophenone was placed in a Pyrex glass container.
After leaving it under sunlight for a minute, this solution was analyzed by high performance liquid chromatography (Zolvax/SLI4.6φ
25 cm; hexane/ethyl acetate system), the peak of 4,4'-bis(2''-norbornadienecarbonyloxy)benzophenone completely disappeared and one new peak appeared. Nuclear magnetic resonance spectra of protons in concentrated deuterochloroform were measured. Expressed in δ value (ppm): 1.56-1.86 (4H); 2.06-2.18 (2H); 2.18-2.33
(4H); 2.43-2.76 (4H); 7.13-7.92 (8H) In addition, a single spot was observed in silica gel-based normal thin layer chromatography (normal layer; hexane-ethyl acetate solvent system) of this benzene solution. From the above, the product obtained by sunlight irradiation is 4,4′-bis-(1″-quadricyclenecarbonyloxy)
It is benzophenone.

Claims (1)

[Claims] 1 4,4′-bis(2″-
norbornadienecarbonyloxy)benzophenone. 2. A method for producing 4,4'-bis(2''-norbornadienecarbonyloxy)benzophenone, characterized by reacting 4,4'-dipropioloyloxyphenyl ketone and cyclopentadiene. 3 4,4' -dihydroxybenzophenone and 2-
A method for producing 4,4'-bis(2''-norbornadienecarbonyloxy)benzophenone, which comprises condensing norbornadienecarboxylic acid in the presence of N,N'-dicyclohexylcarbodiimide as a condensing agent.4 Formula ( ) A light energy storage material containing 4,4'-bis(2''-norbornadienecarbonyloxy)benzophenone as an active ingredient.