Synthesis of chalcogenated polyacenes

Abstract

Chalcogenated polyacenes including organic semiconductors such as tetrathiotetracene, .[.tetraselenotetracene.]., and hexathiopentacene are produced by reaction of a polyacene with elemental sulfur, .[.selenium, and tellurium.]. in the presence of nitrogen-containing hot solvents, preferably alkylated amides. N,N-dimethylformamide is the preferred solvent. The disclosed method of synthesis produces substituted polyacenes of high yield and purity in considerably shorter reaction times than achievable by prior art methods.

I claim: 
     
       1. In a method for preparing a compound having the formula: ##STR4## or ##STR5## wherein X and Y each represent identical atoms selected from the group consisting of sulfur.[., selenium, and tellurium,.]. by a reaction of elemental .[.chalcogen selected from the group consisting of.]. sulfur.[., selenium, and tellurium.]. and a polyacene selected from the group consisting of tetracene and pentacene in the presence of a hot solvent, the improvement which comprises employing an alkylated amide as said solvent. 
     
     
       2. A method for preparing a compound having the formula: ##STR6## or ##STR7## wherein X and Y each represent identical .[.atoms selected from the group consisting of.]. sulfur.[., selenium, and tellurium.]. which comprises reacting an elemental .[.chalcogen selected from the group consisting of.].  sulfur.[., selenium, and tellurium.]. with a polyacene selected from the group consisting of tetracene and pentacene in the presence of a reaction solvent comprising an alkylated amide maintained at about reflux temperatures. 
     
     
       3. A method for preparing a compound having the formula: ##STR8## wherein X represents identical atoms .[.selected from the group consisting of.]. sulfur .[., selenium, and tellurium.]. which comprises reacting an elemental .[.chalcogen selected from the group consisting of.]. sulfur.[., selenium, and tellurium.]. with tetracene in the presence of a reaction solvent comprising an alkylated amide maintained at about reflux temperatures. 
     
     
       4. A method for preparing a compound having the formula: ##STR9## wherein X represents identical atoms .[.selected from the group consisting.]. of sulfur.[., selenium, and tellurium.]. which comprises reacting an elemental .[.chalcogen selected from the group consisting of.]. sulfur.[., selenium, and tellurium.]. with tetracene in the presence of a reaction solvent comprising an alkylated amide maintained at about reflux temperatures, said alkylated amide selected from the group consisting of N,N-dimethylformamide, N,N-diethylformamide, N,N-dimethylacetamide, and N,N,N',N'-tetramethylurea. 
     
     
       5. The method according to claim 4 wherein said alkylated amide is N,N-dimethylformamide. .[.6. The method according to claim 4 wherein the elemental chalcogen is selected from the group consisting of sulfur and selenium, and the alkylated amide is N,N-dimethylformamide..]. .[.7. The method according to claim 6 wherein the elemental chalcogen is sulfur and the alkylated amide is N,N-dimethylformamide..]. .[.8. The method according to claim 6 wherein the elemental chalcogen is selenium and the 
     
     
        alkylated amide is N,N-dimethylformamide..]. 9. A method for preparing a compound having the formula: ##STR10## wherein Y represents identical atoms .[.selected from the group consisting.]. of sulfur.[., selenium, and tellurium,.]. which comprises reacting an elemental .[.chalcogen selected from the group consisting of.]. sulfur.[., selenium, and tellurium.]. with pentacene in the presence of a reaction solvent comprising an alkylated amide maintained at about 
     
     
        reflux temperatures. 10. A method for preparing a compound having the formula: ##STR11## wherein Y represents identical atoms .[.selected from the group consisting.]. of sulfur.[., selenium, and tellurium.]. which comprises reacting an elemental .[.chalcogen selected from the group consisting of.]. sulfur.[., selenium, and tellurium.]. with pentacene in the presence of a reaction solvent comprising an alkylated amide maintained at about reflux temperatures, said alkylated amide selected from the group consisting of N,N-dimethylformamide, N,N-diethylformamide, 
     
     
        N,N-dimethylacetamide, and N,N,N',N'-tetramethylurea. 11. The method according to claim 10 wherein said alkylated amide is N,N-dimethylformamide. .[.12. The method according to claim 10 wherein the elemental chalcogen is sulfur and the alkylated amide is N,N-dimethylformamide..].