TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preparation (claimed): The 2-(5-(thiolan-2-yl)selenophen-2-yl)thiolane derivative (I) is prepared by reacting mono aldehyde-terminated bromo compound and selenium atom-substituted thiophene monomer in toluene as solvent (s2) and tetrakis(triphenylphosphine)palladium(0) as catalyst (a2) under protection of argon, heating, refluxing for 1-7 days, eluting using methylene chloride-petroleum ether as eluent, separating, reacting obtained product with terminated precursor compound in solvent (s1) in presence of catalyst (a1), heating, refluxing for 24 hours, extracting using chloroform, drying the obtained organic phase with anhydrous sodium sulfate, removing solvent under reduced pressure, and separating. Preferred Composition: The mono aldehyde-terminated bromo compound is 5'-bromo-4-octyl-2-aldehyde or 5'-bromo-3,4'-dioctyl-(2,2'-thiophene)-5-aldehyde. The selenium atom-substituted thiophene monomer is 2,5-bis(3-octyl-5-(tributylstannyl)thiophene-2-substituted)diselenophene. The molar ratio of mono aldehyde-terminated bromo compound and selenium atom-substituted thiophene monomer is 2:1-3:1. The molar ratio of solvent (s2) and selenium atom-substituted thiophene monomer is 10-100 l/mol. The molar ratio of catalyst (a2) and selenium atom-substituted thiophene monomer is 0.1-20:100. The terminated precursor compound is 3-ethyl-2-thioxothiazolidin-4-one, 3-oxoundecanenitrile or 2-(3-ethyl-4-oxothiazolidin-2-ylidene)malononitrile. The solvent (s1) is chloroform, dichloromethane and/or tetrahydrofuran. The molar ratio of solvent (s1) and mono aldehyde-terminated bromo compound is 10-30 l/mol. The catalyst (a1) is triethylamine and/or piperidine, or ammonium acetate, ammonium propionate and/or ammonium butyrate. The molar ratio of catalyst (a1) and selenium atom-substituted thiophene monomer is 2:10. SPECIFIC COMPOUNDS - 2 2-(5-(Thiolan-2-yl)selenophen-2-yl)thiolane derivatives i.e. 2-((5Z)-5-((5-(5-(5-(5-(5-(((5Z)-2-(dicyanomethylidene)-3-ethyl-4-oxo-1,3-thiazolidin-5-ylidene)methyl)-3-octylthiophen-2-yl)-3-octylthiophen-2-yl)selenophen-2-yl)-4-octylthiophen-2-yl)-4-octylthiophen-2-yl)methylidene)-3-ethyl-4-oxo-1,3-thiazolidin-2-ylidene)propanedinitrile of formula (Ia), and 2-((5Z)-5-((5-(5-(5-(5-(5-(5-(5-(((5Z)-2-(dicyanomethylidene)-3-ethyl-4-oxo-1,3-thiazolidin-5-ylidene)methyl)-3-octylthiophen-2-yl)-3-octylthiophen-2-yl)-3-octylthiophen-2-yl)selenophen-2-yl)-4-octylthiophen-2-yl)-4-octylthiophen-2-yl)-4-octylthiophen-2-yl)methylidene)-3-ethyl-4-oxo-1,3-thiazolidin-2-ylidene)propanedinitrile are specifically claimed.