United States Patent (19) 11 Patent Number: 4,755,589 Sandman (45) Date of Patent: Jul. 5, 1988

(54) AROMATIC SELENUM COMPOUND POLYMER OTHER PUBLICATIONS Balodia et al., J. Org. Chem. USSR (Engl. Transl.) 15, 75 Inventor: Daniel J. Sandman, Acton, Mass. 343 (1979). Gladysz et al., J. Org. Chem. 43, 1204 (1978). Assignee: GTE Laboratories Incorporated, Battistoni, P. et al., Gazz. Chim, Ital. III, 505 (1981). 73 Sandman, D. J. et al. (1982) J. Chen. Soc., Chem. Com Waltham, Mass. mun. pp. 1133-1134. Ohnishi, S. et al. (1982) Chemistry Letters, pp. (21) Appl. No.: 870,122 1841-1842. Endres, H. et al. (1982) Mol. Cryst. Liq. Cryst. 86 22 Filed: Jun. 3, 1986 111-122. K. Y. Jen et al., J. Polymer Sci., Polymer Lett. 21, 441 (1983). Related U.S. Application Data S. Tanaka, et al., Makromol. Chem., Rapid Commun. 4, 62 Division of Ser. No. 507,156, Jun. 23, 1983, Pat. No. 231-235 (1983). 4,597,914. T. Hasegawa et al., J. Polymer Sci., Polymer Lett. 22, 365 (1984). (51) Int. Cl* ...... CO8G 83/00 Primary Examiner-Harold D. Anderson 52) U.S. C...... 528/397; 528/388 Attorney, Agent, or Firm-Hamilton, Brook, Smith & 58 Field of Search ...... 528/397,388 Reynolds 56) References Cited 57 ABSTRACT U.S. PATENT DOCUMENTS This invention constitutes a method for preparing mo lecular and polymeric aromatic compounds 3,149,101 9/1964 Hubel et al...... 260/239 such as bis-phenyl selenide and poly(p-phenylene sele 3,354,129 11/1967 Edmonds et al...... 528/265 3,790,536 2/1974 Vidaurri...... 528/388 nide). The method comprises reacting an aryl halide 3,965,049 6/1976 Grushkin et al...... 520/1 with an alkali metal selenide reagent formed in an 4,344,869 8/1982 Binne et al...... 252/517 aprotic solvent. 4,540,620 9/1985 Johnson et al...... 528/388 4,597,914 7/1986 Sandman ...... 528/397 2 Claims, No Drawings 4,755,589 1. 2 synthesis of these compounds under significantly milder AROMATIC COMPOUND POLYMER conditions. This application is a division, of application Ser. No. BEST MODE OF CARRYING OUT THE 507,156 filed June 23, 1983 now U.S. Pat. No. 4,549,914. 5 INVENTION The alkali metal selenide reagent is formed in an DESCRIPTION aprotic solvent such as N,N-dimethylformamide, hex 1. Field of the Invention amethylphosphoramide or N-methylpyrrolidinone. This invention is in the field of organic chemistry and Finely divided elemental selenium is added to the sol relates to methods of synthesizing organometallic com 10 vent, and a suspension of selenium is formed by stirring. pounds containing selenium. Specifically, it relates to a The suspension is heated to about 100 C. and then method of synthesizing molecular and polymeric aro pieces of alkali metal are added to form a mixture in matic selenium compounds and a reagent useful in the which the molar ratio of alkali metal to selenium is preparation of such compounds. about 2:1. The resulting alkali metal selenide has the 2. Background of the Invention 15 M2Se wherein M is an alkali metal. Poly(p-phenylene sulfide)(PPS) is a crystalline, aro The alkali metal employed in the production of the matic polymer comprising benzene rings linked with intermediate selenide reagent may be lithium, sodium or sulfur atoms in the para position. The polymer exhibits . Sodium however is the preferred metal be several advantageous properties including high-temper cause it is most convenient to use. ature stability, flame resistance and good chemical resis 20 The reaction to form the alkal metal selenide reagent, tance. PPS is used widely as a coating material and in and the reaction of the alkali metal selenide reagent injection and compression molding processes. Recently with the aromatic halogen compound may be carried PPS has received attention as an example of a polymer out in the same solvent. Thus, after the reagent is syn without a continuous carbon ar system which becomes thesized, the aromatic halogen reactant is added di highly conducting on exposure to strong oxidants. See 25 rectly to the reaction mixture containing the alkali e.g., European patent application No. 80107176.2. metal selenide reagent. The entire synthetic procedure The usefulness of PPS has generated interest in the may be carried out under an atmosphere of an inert gas selenium analog of PPS, poly(p-phenylene selenide) such as argon or one of the other noble gases. This (PPSe). At least one unsuccessful attempt to prepare prevents undesirable side reactions with moisture or the PPSe from Na2Se and p-dibromobenzene in ethyl ace 30 components of air. tate solution has been reported See, Okamoto et al., After the intermediate alkali metal selenide reagent is Ann. N.Y. Acad. Sci 192:60 (1972). Balotis et al. have reacted with an aromatic halogen compound to form reported the synthesis of the metallocyclic compound the desired molecular or polymeric organic selenide, tetraselenotetracene from sodium diselenide (Na2Se2) in the product is then separated from the reaction mixture dimethylformamide solution. 35 by conventional techniques. For the most part the re sulting selenide compounds are not air-sensitive and SUMMARY OF THE INVENTION therefore may be subjected to purification techniques This invention constitutes a method for the synthesis such as recrystallization, sublimation or the like without of conjugated molecular and polymeric aromatic sele 40 exercise of excessive care. nium compounds. The method involves the reaction of According to the method of this invention, bis aryl aromatic halides with an alkali metal monoselenide selenide compounds are produced by the alkali metal reagent such as Na2Se or K2Se. According to the selenide reagent with a monohaloaromatic compound. method of this invention, the alkali metal selenide rea The reaction between the alkali metal selenide and the gent is formed directly from an alkali metal and sele 45 aryl halide in a molar ratio of substantially 1:2 gives nium in a polar aprotic solvent, and the reagent is then products of the general formula Ar-Se-Ar where Ar reacted with an appropriate aromatic halide in the same signifies the particular aromatic group of the aryl halide solvent system to form the desired molecular or poly reactant. The synthesis of bis aryl is typified meric organic selenium compound. by the reaction of 2-bromonaphthalene with sodium Examples of some of the molecular aromatic sele 50 selenide to give bis-(3-naphthyl)selenide. nides which may be synthesized by this method are bis-phenyl selenide, bis(2-naphthyl) selenide and bis(9- anthracenyl) selenide. Molecular aromatic selenides Br have useful bactericidal activity, antiseptic activity and anti-inflammatory activity. See e.g. "Organic Selenium 55 Compounds: Their Chemistry and Biology" ed. D. L. Klayman and W. H. H. Gunther, Wiley-Interscience Se (1973). Examples of some of the polymeric aromatic selenides which may be produced are poly(p-phenylene -- 2NaBr selenide) and poly(9,10-anthraceneselenide). Polymeric aromatic selenides are precursors to conducting poly e.S. Aromatic polymers are produced by reacting the The invention provides a simple and direct method alkali metal selenide. reagent with a dihaloaromatic for synthesizing previously-known and new or compound. The reaction between the alkali metal sele ganoselenium compounds. The method eliminates the 65 nide and the dihalo-aromatic compound in a molar ratio use of liquid or other nitrogenous solvents, of substantially 1:1 gives polymeric aromatic selenides which are used currently in the synthesis of or of the general formula Ar-Se-n. The synthesis of ganoselenium compounds, and thus provides for the organic polymeric selenides is typified by the reaction 4,755,589 3 4. of p-dibromobenzene with to give Calculated for -C6H4Se-n: 46.48; H, 2.60; Se, 50.92. poly-(p-phenylene selenide) (PPSe) Observed: C, 41.36; H, 2.26; Se, 52.15; Br, 1.57. The observed elemental analysis corresponds to a Br composition of C60H3.91Sel. 15 and based on bromine 5 analysis, a molecular weight of 5000 or 10,000 is esti mated for one and two bromine atoms per polymer chain, respectively. The 15% atomic excess of selenium + Na2Se-G- -KO)-- is attributed to diselenide linkages in the polymer. The x-ray diffraction pattern of this polymer is similar to Br O that described in Example 1 and shows no elemental As shown in the equation, p-dibromobenzene reacts selenium. with the sodium selenide reagent to form PPSe. Nota EXAMPLE 3 bly, these reaction conditions are significantly milder Preparation of PPSe from p-dichlorobenzene in than those used for the synthesis of poly(p-phenylene 15 sulfide) (PPS). It is suspected that the facility of the N,N-dimethylformamide (DMF) reaction is due to the operation of an SRN1 mechanism. A sodium selenide reagent was prepared in DMF (40 The polymeric selenides, such as PPSe and poly(9,10 ml) in the usual manner from selenium (2.17 g, 0.0275 anthraceneselenide), are useful as precursors to con gm-atom) and sodium (1.30 g, 0.055 gm-atom under ducting polymers. For example, exposure of PPSe to 2O argon. To this reagent was added p-dichlorobenzene arsenic pentafluoride (at 100 Torr) for 5 hours at 40 C. (3.675 g, 25 mmole) This mixture was kept at a bath results in a conductivy for the treated polymer of about temperature of 140-145 for 18 hours and then at 10-2-10-3 (ohm cm)- 1. B 170°-175 for 100 hours. The product was isolated as The following specific examples further illustrate the previously described to give PPSe as a light brown invention. 25 powder, 0.188 g, 4.85% yield. The infrared spectrum EXAMPLE 1. and x-ray diffraction pattern corresponded to those of Preparation of poly(p-phenyleneselenide) PPSe. To a magnetically stirred suspension of selenium EXAMPLE 4. (2.17 g, 0.0275 gm-atom) in N-methylpyrrolidinone (50 3O Preparation of PPSe from p-dichlorobenzene in ml) under argon at ca. 110 was added pieces of sodium N-methylpyrrolidinone (NMP) (1.30 g, 0.055gm atom) over a one hour period. After stirring for an additional thirty minutes, solid p A sodium selenide reagent was prepared in NMP (15 dibromobenzene (5.90 g, 0.025 mole) was added, and ml) from sodium (1.30 g) and selenium 2, 17 g) under the mixture was heated at 170 for twenty hours. The 35 argon. To this reagent was added p-dichlorobenzene mixture was allowed to cool to room temperature and (3.675 g), and the mixture was heated at bath tempera solid product was precipitated with methanol and wa ture 155-160 for sixteen hours and then at 160-170 ter. The product was filtered and washed consecutively for eighty hours. The product was isolated as previ with saturated sodium sulfide, water, and methanol. ously to give PPSe, 0.553 g, 14.3% yield, with an infra The yellowish solid was Soxhlet extracted for 15 hours 40 red spectrum in accord with previous observations. with tetrahydrofuran to give a yellow solid, 0.395 g (10% yield). The x-ray diffraction pattern of this solid EXAMPLE 5 exhibits a strong reflection at 20=20.0 (d = 4.44 A) Preparation of PPSe from p-dibromobenzene and K2Se compared to PPS(3) which exhibits a strong reflection at A potassium selenide reagent was prepared in DMF d=4.36A. An elemental analysis of the product yielded 45 (40 ml) under argon from potassium (2.15g, 0.055 gm the following results: Calculated for -C6H4Se-r: atom) and selenium (2.17 g, 0.0275 gm-atom). To this 46.48; H, 2.60; Se=50.92. Found: C, 43.23; H, 2.54; Se, was added p-dibromobenzene (5.90 g, 25 mmole) and 50.06. the mixture was heated at 145-150 for 40 hours. The EXAMPLE b 2 product was isolated in the usual manner to give PPSe Preparation of poly-p(phenyleneselenide) from 50 (602 mg, 15.5% yield), m.p. 221-245 with infrared p-dibromobenzene in N,N-dimethylformamide spectrum and x-ray diffraction pattern in accord with earlier samples of PPSe. A sodium selenide reagent was prepared in N,N- dimethylformamide (40 ml) from sodium (1.30 g, 0.055 EXAMPLE 6 gm atom) and selenium (2.17 g 0.0275 gm atom) at 55 Preparation of poly(9,10-anthraceneselenide) 100-110° C. under argon. To this mixture, p-dibromo benzene (5.90g, 25 mmole) was added, and the mixture To a magnetically stirred suspension of selenium was heated for twenty hours. The reaction mixture was (0.79 g, 0.01 gm atom) in N,N-dimethylformamide diluted with methanol (40 ml) and poured into saturated (DMF, 20 ml) under argon at ca. 120° C. was added sodium chloride. The solid precipitate was filtered and 60 pieces of sodium (0.46g, 0.02 gm atom), followed by an washed sequentially with water (100 ml), warm sodium additional 60 ml DMF. 9,10-Dibromoanthracene (3.36 sulfide solution (200 ml), water (100 ml), and methanol g, 0.01 mole) was added as a solid, and the mixture was (60 ml). The solid was continuously extracted with heated at 120-130 for twenty hours. The cooled mix tetrahydrofuran until the extracts were colorless. The ture was filtered to give a yellow-orange solid which remaining solid after vacuum drying weighed 3.10 g 65 was consecutively washed with saturated sodium sul (80% yield) and on heating in a capillary darkened at fide, water, and methanol, followed by vacuum drying 200 and melted irreversibly by 233 . An elemental to give 0.98g powder (38% yield), mp300. The prod analysis for the product yielded the following results: uct was amorphous by X-ray diffraction, and its solid 4,755,589 5 6 state spectrum, measured by diffuse reflectance, exhibits EXAMPLE 8 an absorption maximum at 460 nm. An elemental analy Preparation of bis-(3-Naphthyl) selenide from sis for the product yielded the following results: 2-bromonaphthalene and K2Se Calculated for (C14H8Se.): C, 65.90; H, 3.16; Se, 5 A potassium selenide reagents was formed in hexame thylphosphoramide (40 ml) from potassium (0.78 gm, 30.94. Found: C, 63.12; H, 3.23; Se, 30.27; Br, 1.57. 0.02 gm-atom) and selenium (0.79 g, 0.01 gm atom) under argon at 70-80. The bath temperature was EXAMPLE 7 raised to 90-100 over thirty minutes and 2 Preparation of Bis(9-anthracenyl) selenide O bromonaphthalene (4.14 g, 0.02 mmole) was added. Bath temperature was raised to 170°-180° and after 23.5 To a magnetically stirred suspension of selenium hours at that temperature, the mixture was allowed to cool to room temperature and poured into salt water (0.295 g, 0.00375gm atom) in DMF (15 ml) at 110' C. (150 ml). A dark precipitate was isolated by filtration was added sodium (0.173g, 0.0075gm atom). After one 5 and volatiles were removed by vacuum sublimation. hour, 9-bromoanthracene (0.482 g, 1.88 mmole) fol The residue was chromatographed on silica gel (40 g) and eluted with 50:50 v/v hexane-benzene. One gram of lowed by DMF (15 ml) was added. white solid and the desired compound was isolated; the The mixture was heated at 140 for 16 hours when it 20 analytical sample exhibited m.p. 131-133. The follow was cooled to room temperature and poured into water. ing absorption spectrum was observed in hexane solu tion, Amann (log10e): 335 sh(3.63), 307sh (4.11), 299 sh This mixture was extracted with dichloromethane; the (4.16), 278 sh (4.25), 259 sh (4.59), 252 sh (4.55), 229 sh extracts were dried over magnesium sulfate and evapo (5.05). An elemental analysis to the product yielded the following results: Calculated for C20H14Se: C, 72.07; H, rated. The residue was chromatographed on silica gel in 25 4.23; Se, 23.69. Found: C, 72.06; H, 4.00; Se, 23.88. hexane, and the desired product crystallized from a What is claimed is: dichloromethanechloroform mixture to give 0.250 g 1. Poly(9,10-anthracenyl selenide). 2. Poly(p-phenylene selenide) having a 15% atomic (31% yield), mp 259-263, identified by the molecular excess of selenium. in the mass spectrum. 30

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