Reduction of 1,2-diselenacyclopentane (1) with NaBH4 under alkaline conditions followed by condensation with dichlorides or ditosylates gave six diselenacrown ethers I [Z = CH2CH2OCH2CH2, (CH2CH2O)2CH2CH2, (CH2CH2O)3CH2CH2, o-C6H4(OCH2CH2)2, o-C6H4(OCH2CH2)(OCH2CH2OCH2CH2), m-C6H4(OCH2CH2)2 2a-7a] and seven tetraselenacrown ethers II [same Z, p-C6H4(OCH2CH2)2 2b-8b]. At the same time, the Pd complexes of crown ethers 5a and 5b were prepared by reacting 5a and 5b with Pd dichloride. Their complexing characteristics are discussed

Key words: INFRARED SPECTROPHOTOMETRY, ELEMENTAL ANALYSIS, MASS SPECTROGRAPHY, ICP-ATOMIC EMISSION SPECTROMETRY, PALLADIUM COMPLEX, SODIUM BOROHYDRIDE, CROWN ETHER