JPH0152054B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an oxygen adsorbing/desorbing agent comprising hydrophobic polymer particles embedded with so-called iron()porphyrin complexes.

Iron ()porphyrin complexes in hemoglobin and myoglobin reversibly adsorb and desorb oxygen molecules. In order to synthesize a complex with an oxygen adsorption/desorption function similar to such a natural polyphyrin iron () complex,
Many studies have been published so far. Examples include J.P. Collman, Accounts of Chemical
Research 10 265 (1977); F. Basolo, B.M.
Hoffman and JAJbers, ibid., 8 384
(1975); Tsuchida, Hasegawa and
Kanayama Macromolecules 1978, 11, 947―
955 etc. In particular, iron()-5,10,15,20-tetra[α,α,α,α-(O-piparamidofu enyl)] porphyrin complex (JP Collman et al.,
Journal of American Chemical Society 97
1427 (1975)). However, if even a small amount of water coexists with this complex, it will be immediately oxidized, making it impossible to generate an oxygen complex. For this reason, the development of iron()porphyrin complexes that provide oxygen complexes even in the coexistence of water at room temperature is being promoted.

Therefore, an object of the present invention is to provide a porphyrin iron() complex system that can form an oxygen complex in an aqueous phase or a water-coexisting solvent system at room temperature and can reversibly adsorb and desorb oxygen depending on the oxygen partial pressure difference. There is a particular thing.

According to this invention, the above objectives are: (Here, R ₁ is a group that does not inhibit the coordination of the imidazole group to the central iron, R ₂ is an alkyl trityl group or a substituted trityl group, and R ₃ and R ₄ are hydrogen or a substituent, respectively.) Iron () 5, 10, 15, 20-tetra [α, α,
This can be achieved by embedding an α,α-(O-pivalamidophenyl)]porphyrin (hereinafter referred to as Fe()TpivPP) complex into hydrophobic polymer particles and dispersing them in an aqueous medium.

The present inventors thought that by placing the iron()porphyrin complex in a specially designed hydrophobic field, it is possible to form an oxygen complex even in a system where water coexists. Although it is conceivable to use a micelle forming agent such as a surfactant to place an iron complex with a poorly water-soluble porphyrin as a ligand in a hydrophobic field in water, the present inventors have developed Fe()Tpiv PP. The present inventors have discovered that a stable oxygen complex can be formed by embedding it in hydrophobic polymer particles, and have completed the present invention.

The Fe()Tpiv PP complex alone has almost no effect of adsorbing and desorbing oxygen through coordination, and in order to achieve this purpose, it is necessary to coordinate a basic ligand at the axial position. In this invention, as this axial ligand, as shown in the above formula, The substituted imidazole shown is used. Here, R ₁ is a group that does not inhibit the coordination of the imidazole to Fe()Tpiv PP, and is preferably a methyl group, an ethyl group, or a propyl group (including an n-propyl group and an isopropyl group). R ₂ is an alkyl group such as a C ₁ -C ₃₀ alkyl group or a trityl group,
It is a substituted trityl group. R ₃ and R ₄ are hydrogen or any substituent. Examples of such substituted imidazoles include 1,2-dimethylimidazole, 1-ethyl-2-methylimidazole, 1
-n-lauryl-2-methylimidazole, 1-
Trityl-2-methylimidazole and the like. It is important that the substituted imidazole as an axial ligand has the above substituent (R ₁ ) at the 2-position. When a substituent is present at the 2-position, the substituted imidazole becomes Fe Tpiv
Only a five-coordinated deoxy complex is formed, with the other coordination sites being empty, with oxygen coordinating to one of the 5th and 6th coordination sites of the central iron of PP. It becomes easier to coordinate molecules. However, since imidazole having no substituent R ₁ at the 2-position coordinates to both the fifth and sixth coordination sites, oxygen cannot be adsorbed.

Examples of hydrophobic polymers in which the Fe()Tpiv PP complex is embedded include polystyrene (preferred);
These include polyethylene, polypropylene, poly-α-methylstyrene, O-alkyl (eg, methyl) dextran, long-chain alkyl (eg, n-lauryl) ester of polyglutamic acid, polyphenylalanine, and the like. Note that polyamide, polyurethane, saturated polyester, etc. can also be used. To embed Fe()Tpiv PP in such hydrophobic polymers, e.g. in an inert atmosphere (e.g. nitrogen gas)
Among them, Fe()Tpiv PP, an excess amount of substituted imidazole and a hydrophobic polymer e.g. Fe Tpiv PP1
(at least 10 grams per gram) in a suitable solvent such as toluene and reduce the central iron of Fe Tpiv PP to its divalent state with a reducing agent such as sodium dithionite. Next, the solvent layer is separated, dehydrated, and freeze-dried to form Fe()Tpiv.
Hydrophobic polymer particles embedded with PP complexes are obtained. There is no particular limit to the size of these particles, but the diameter
Thicknesses of 0.2 mm or less (usually 0.01 μ or more) can be made using the above method.

When the hydrophobic polymer particles thus obtained are dispersed in water (for example, 200 grams or less per water), the oxygen adsorbing/desorbing agent of the present invention can be obtained. Preferably, a surface wettability improver and/or a thickener may be added in order to stably disperse the particles in water. There are various surfactants as surface wettability improvers, which may be ionic or nonionic. Examples of surfactants include anionic surfactants such as sodium dodecyl sulfate, sodium dodecyl sulfonate, sodium dodecyl-N-sarcosinate and disodium N-laurylglutamate, cetyltrimethylammonium bromide, tetradecylammonium bromide. and cationic surfactants such as dodecylpyrimidinium chloride, as well as palmitoyl lysolecithin, dodecyl-N-betaine, polyoxyethylene alcohol, polyoxyethylene isoalcohol, polyoxyethylene p-t-octylphenol, polyoxyethylene nonyl Nonionic surfactants such as phenols, polyoxyethylene esters of fatty acids, polyoxyethylene sorbit esters, and polyoxyethylene nonylphenol ethers. All of these are commercially available. There are no particular limitations on the amount of surfactant used. Generally, 1 to 100% of the weight of the hydrophobic polymer particles is sufficient.

The thickener has the function of increasing the viscosity of the dispersion and retaining hydrophobic polymer particles with a light specific gravity in the dispersion system. The thickener may be any water-soluble polymer; specific examples include sodium salt of carboxymethyl cellulose, dextran, hydroxyethyl starch,
These include polyethylene glycol, polyvinyl alcohol, polyvinylpyrrolidone, hyaluronic acid, polygalacturonic acid, and mucopolysaccharides.

According to this invention, Fe()Tpiv PP embedded in hydrophobic polymer particles stably exhibits a reversible oxygen adsorption/desorption function and easily forms an oxygen complex even at room temperature and in the presence of water. That is, the oxygen adsorbing and desorbing agent of the present invention exhibits an excellent oxygen transporting action that can operate at room temperature and in the coexistence of water.

Examples of this invention will be described below.

Example 1 5, 10, 15, 20-tetra [α, α, α, α-
(O-pivalamidophenyl)] 2 mg of porphine iron () bromide (hereinafter abbreviated as Fe()Tpiv PP/Br), 0.84 mg of 1,2-dimethylimidazole (hereinafter abbreviated as Me ₂ Im), and After dissolving 100 mg of poly(styrene) in 10 ml of benzene, 5 ml of an aqueous solution of dithionite was added in a nitrogen gas atmosphere, thoroughly shaken, and allowed to stand. A benzene layer was collected and dehydrated using 3 Å molecular sieves. The benzene solution was freeze-dried to obtain a red powder.
Separately, an aqueous solution (10 ml) containing 0.05 wt/vol% Triton was repeatedly frozen and degassed and added to the above red powder under a nitrogen gas atmosphere, and subjected to ultrasonic stirring treatment for 10 minutes under a nitrogen gas atmosphere to prepare a fine particle water spray. The visible absorption spectrum of the prepared water in a nitrogen gas atmosphere is shown in spectrum a in FIG. The shape of the absorption spectrum and the absorption maximum wavelength are 561mm and 530mm (shoulder)
and the desired complex, i.e. 5, 10, 15, 20-
A tetra[α,α,α,α-(O-pivalamidophenyl)]porphine iron()-mono(1,2-dimethylimidazole) complex was obtained.

Example 2 Oxygen gas was blown into the microparticle-dispersed water prepared in Example 1 at room temperature to obtain spectrum b in FIG. This visible absorption spectrum matches the spectrum of an oxygenated complex in anhydrous toluene, and supports the formation of an oxygen complex in which 1 mole of oxygen molecules are bound to 1 mole of iron (). When nitrogen gas is bubbled into an aqueous system showing spectrum b,
A spectrum c similar to the initial spectrum a was obtained (Figure 2). When oxygen gas was introduced into an aqueous system exhibiting spectrum c at room temperature, an oxygenated complex spectrum d similar to spectrum b was obtained. This results in
It was confirmed that the porphyrin iron() complex system prepared in Example 1 reversibly adsorbs and desorbs oxygen molecules. The stability of the above-mentioned oxygenated complex was tracked by the change in visible absorption spectrum over time, and its half-life was found to be more than one day at room temperature.

Example 3 Fe()Tpiv PP mono(Me ₂ Im) was prepared using exactly the same conditions and methods as in Example 1 except that 100 mg of O-methyldextran was used instead of poly(styrene) and chloroform was used instead of benzene. A fine particle dispersion of solid O-methyldextran in water was obtained. Using this microparticle-dispersed water using the method of Example 2, generation of an oxygen complex and reversible oxygen adsorption/desorption were confirmed. Although the stability of the oxygen complex at room temperature was slightly lower than that of the poly(styrene) system, it showed considerable stability.

Example 4 Exactly the same method as in Example 1 was used except that 50 mg of poly(L-glutamic acid-n-lauryl ester) was used instead of poly(styrene) and the amount of Me ₂ Im was doubled. A fine particle dispersion water was obtained. This microparticle-dispersed water was examined using the method of Example 2, and the generation of oxygen complexes and reversible oxygen adsorption and desorption were confirmed.

Example 5 In Example 1, 5,10 ，
Dispersion of fine particles in which 15,20-tetra[α,α,α,α-(O-pivalamidophenyl)]porphyrin iron ()-mono(1-trityl-2-methylimidazole) complex is embedded in polystyrene particles. An aqueous solution was obtained. Adsorption and desorption of oxygen was confirmed according to the method of Example 2. The half-life of the oxygen complex at room temperature was more than one day.

Note that 1-trityl-2-methylimidazole used in this example was synthesized as follows.

2-Methylimidazole-silver salt 4.3gr (0.023
mol) was suspended and stirred in 50 ml of toluene, 7.0 gr (0.025 mol) of trityl chloride was added, and the mixture was heated under reflux for 10 hours. The temperature was returned to room temperature, insoluble materials were separated, and the liquid was concentrated by evaporation. The residue was purified using a silica gel column (200 gr, CNCl ₃ /MeOH=20/1). The target product was synthesized by recrystallization from benzene-n-heptane system. Yield: 3.34gr, yield: 45%. Mass spectrum M ⁺ = 324.

1H-NMR spectrum (CDCl ₃ , TMS) δ
(ppm): 7.00-7.40 (15H, m, phenyl nucleus),
6.86 and 6.76 (1H, 1H, d, J = 1 Hz, imidazole nucleus 4th and 5th positions), 1.67 (3H, S, -CH ₃ at imidazole 2nd position).

IR spectrum (KBr tablet) Cm ^-1 : 3350,
3070, 3030, 1600, 1520, 1490, 1450, 1395,
1305, 1240, 1180, 1140, 1070, 1035, 1000,
980, 910, 880, 865, 760, 750, 700.

[Brief explanation of drawings]

FIGS. 1 and 2 are spectral diagrams of the oxygenation and deoxygenation states of the oxygen adsorbent/desorbent of the present invention.

Claims (1)

[Claims] 1 formula (Here, R ₁ is a group that does not inhibit coordination to the central iron of the imidazole to which it is bonded, R ₂ is an alkyl group, trityl group, or substituted trityl group, and R ₃ and R ₄ are each hydrogen or a substituent.) Iron ()-5, 10, 15, 20-tetra [α, α,
α,α(O-pivalamidophenyl)] An oxygen adsorbent/desorbent consisting of a dispersion liquid in which hydrophobic polymer particles embedded with a porphyrin complex are dispersed in an aqueous medium. 2. The oxygen adsorbing/desorbing agent according to claim 1, wherein R ₁ is a methyl group, an ethyl group, or a propyl group. 3. The oxygen adsorbing/desorbing agent according to claim 1 or 2, wherein the hydrophobic polymer is polystyrene, O-methyldextran, or poly(L-glutamic acid n-lauryl ester). 4. Claims 1 to 3, wherein the dispersion further contains a wettability improver for hydrophobic polymer particles.
The oxygen adsorbing and desorbing agent according to any of the above. 5. The oxygen adsorbing/desorbing agent according to any one of claims 1 to 4, wherein the dispersion further contains a thickener.