Polymeric 1,3,4-Thiadiazoles

Ethyl-l,2,3-thiadiazole 44 is readily brominated at its pseudo benzylic position and subsequent elimination afforded the vinyl thiadiazole 45 (Scheme 5) <1986LA1334, 1986LA1344>. To prevent polymerization of the vinyl thiadiazole, hydroquinone was added during the elimination step. 

The bromine atoms in 2,5-dibromo-l,3,4-thiadiazole 54 undergo a palladium-catalyzed Stille reaction with the organostannyl derivative 55 (Equation 7) <1998CEJ2211>. The thiadiazole 54 was co-polymerized with diethynyl benzene 56 (Equation 8) and diethynyl pyrrole in a Sonogashira cross-coupling reaction <2005MM4687>. 

Already in the first experiment of this series (1990) we found136 that photolysis or pyrolysis of benzotris(thiadiazole) 98 leads to pentatetraenedithione (99), the third carbondisulfide beyond the already known low members CS2 and C3S2. The long-chain derivative 99 can be kept in a solution even at room temperature for some time without polymerization. 

Thiirene intermediates in the photolysis of 1,2,3-thiadiazoles readily undergo ring opening to a diradical which can be trapped by reaction with an alkyne (Scheme 25) (79CB1769). Significant polymerization is not observed. 

Becker et al. (5) prepared polymeric organic light-emitting diodes by copolymerizing 4,7-dibromobenzo[l,2,5]-thiadiazole, (IV), and 4,7-dibromobenzo-furazone, (V), with spirobifluorene derivatives. Polymerizations were performed under Yamamoto conditions. 

Amino-1,2,4-thiadiazoles79 and their 3-alkoxy-, 3-alkylmercapto-, and 3-dialkylamino derivatives84 have been claimed to be useful intermediates in the manufacture of dyes,84 pharmaceuticals,84 and materials valuable in pest control.79 Mono-azo dyes derived from diazotized 5-amino-l,2,4-thiadiazoles and coupling components of the benzene series are especially suitable for dyeing polymeric materials such as acetate rayon, polyamides, polyurethanes, polyesters, and... 

Partially and perfluorinated thioketones and thioaldehyde were stabilized as anthracene adducts (70). The adducts (70) were prepared in moderate yield from the corresponding carbonyl compounds with P4S10 or Lawesson s reagent in the presence of anthracene under toluene reflux. The generated thiocarbonyl compounds are not accessible in bulk due to their tendency towards polymerization. By thermolysis of the anthracene adducts (70) in the presence of C,N-bis(triisopropylsilyl)nitrilimine (NI), 1,3,4-thiadiazole derivatives (71) were obtained. Also, 1,3-dipolar cycloaddition with bis(trimethylstannyl)diazomethane (BTSD) to give consecutive products (72) from a 1,2-metallotropic migration of primary adducts was discussed. [95LA95]... 

Di(2-thienyl)thieno[3,4-c][l,2,5]thiadiazole (178) has been polymerized to give a narrow band gap heterocyclic polymer with interesting optical and electrochemical properties <93SM1251>. Stable dithiazolyl radicals, such as (18) and (19), are useful as inhibitors and stabilizers for radical reactions <82EGP156366>. 

Horclois et al.239 have suggested the use of NMA as a solvent for the reaction of thiosemicarbazide with carbon disulfide to produce 2-amino-5-mercapto-l,3,4-thiadiazole. The reaction proceeds at a lower pressure (atmospheric) and at a lower temperature than the comparable reaction in water. Campbell240 has described the polymerization of acrylonitrile by BF3 in amide solvents including NMA. 

These tellurium-containing polymers were checked for their catalytic activity in the ep-oxidation of olefins and as oxidizing agents. The polymeric 4-methoxyphenyl tellurium oxide did not react with amines, amides, alcohols, or phenols, but oxidized hydroquin-ones to quinones, thiols to disulfides, thioketones to ketones, thioesters to esters, and thiobenzamides in organic solvents to cyanobenzenes and in acetic acid to 2,5-diaryl-4,l, 3-thiadiazoles. ... 

PCS of the II type are the most interesting as modifiers. Many types of polymers belong to this type. Their chains contain heteroatoms N, O, S with non-distributed -electrons. Among them are polybenzimidazoles, thiazoles, thiadiazoles, polymers of hydrocyanic acid PCS with end heteroatoms - polymethynes, cyan dyes and their analogs, PCS with repeated heteroatoms in conjugated chains - polyazines, polyschiff bases, polymeric azo- and diazocompounds and so on. 

Vinyl-substituted 1,2,5-thiadiazole 255, a potential precursor to bis(l,2,5-thiadiazole) ligand 256 for coordination polymerization, is derived from methionine amide 253 via heterocyclization and oxidative elimination. However, attempts to perform the olefin metathesis were not successful <04TL5441>. 

Bis(dithio)thiadiazoles (e.g., 524)113,515 and bis(thiosulfenamides)516 are employed as corrosion inhibitors in lubricants. The antiwear and extreme-pressure properties of lubricating greases are improved by the addition of (polymeric) 3,5-dimercapto-l,2,4-thiadiazole,517 2,4-dialky 1-1,2,4-thiadiazo-... 

Electroluminescent conjugated polymers can be synthesized by incorporating high electronegative heterocyclic groups, such as 1,3,4-oxadiazole, 1,3,4-thiadiazole and 1,2,4-triazole moieties. These electroluminescent polymers are obtained by polymerization of a bis-(halomethyl) aromatic monomer modified with a heterocyclic group. ... 

S. J. Visco et al. proposed a new rechargeable battery system at room temperature by using reversible polymerization reaction of organic sulfur compound in place of inorganic sulfur. As for 2,5-dimercapto 1,3,4-thiadiazole (DMcT) chemical... 

In 1975, Russo reported that when N,N -diphenylbenzidine or N,N -diphenyl-l,4-phenylene diamine were interfacially polymerized with a mixture of 1,2,5-thiadiazole and 3,4-furan dicarbonyl chloride, co-polyamides were obtained having good heat resistance, dielectric properties, and mechanical properties, "comparable to those of other construction materials."... 

Synthesis from -Thiocyanato-2,i diazabuta-, 3-dienes. l-Chloro-l,4-di-phenyl-2,3-diazabuta-l,3-diene (113) is readily converted by potassium thiocyanate into the corresponding 1-thiocyanato-compound (114) from which 1,3,4-thiadiazoles may be obtained. Thus, thermolysis of (114) in boiling toluene produces, in addition to much polymeric material (53%),... 

DBP) as a donor blended with C70 as acceptor and a layer of 2-((7-(5-(dip-tolylamino)thiophen-2-yl)benzo[c] [1,2,5] thiadiazol-4-yl)methylene)malononitrile (DTDCTB) as a donor blended with Cgo as acceptor [226]. Such cells are directly competing with solution-processed plastic solar cells consisting of at least one polymeric organic donor and, typically, a molecular organic acceptor, which have also reached similar efficiency levels of 6.1 % [227], 7.4 % [228], 8.7 % [229], and 9.4 % [230] for different material combinations in conventional single-cell device structures, 10.6 % in a tandem cell [231], and even 11.5 % [232] or 11.8 % [233] in triple-junction devices. 

Asymmetric electrochemical polymerization of thieno[3,2-h]thiophene (1), 2,2 -bisthieno[3,2-h]thiophene (bis-TT, 48), and 4,7-bis-thieno[3,2-h]thiophen-2-yl-benzo[l,2,5]thiadiazole (TT-Btdaz, 113) [46], linked through the TT 2-positions, was carried out in cholesteric liquid crystals (CLCs) (Scheme 25) [47]. 

The rod-like thiadiazole derivative 3 is liquid crystalline and shows a smectic as well as a nematic LC phase with the following phase behaviour c 103 Sa 180 n 203 i. An acrylate monomer was prepared by hydroboration of the terminal double bond and subsequent esterification with acryloyl chloride and then polymerized. The resulting polymer 5 exhibits a mesophase which has not yet been identified. 

The unstable thioketenes were obtained by thermolysis of 1,2,3-thiadiazole, and the unstable selenoketenes were similarly generated and characterized in the vapor phase The highly reactive fulvene substituted selenoketene 2 was also obtained in the thermolysis of benzo-l,2,3-selenadiazole 1, and the red precipitate collected at -196 °C polymerizes violently on warming". ... 

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