Studies on Selena-Macrocyclic Amides Synthesis and Structural Characterization of 7-Phenyl-5, 9-dioxo-1-selena-4, 7, 10-triazacyclododecane and 6-(4-Nitrobenzyl )-5, 9-dioxo-1, 4, 7, 10-selenatriazacyclododecane

7-Phenyl-5, 9-dioxo-1-selena-4, 7, 10-triazacyclododecane (1) and 6-(4-Nitrobenzyl)-5, 9-dioxo-1, 4, 7, 10-selenatriazacycloedecane (2) were synthesizedby condensation of bis (2-aminoethyl) selenide and corresponding diethyl esters. Theircrystal structures were determined. Crystal data: C14H19N3O2Se (1), Mr= 340. 28,space group P212121, a=5. 328(5), b= 14. 043(5), c= 18. 569(5) A, V= 1403(1)A3, Z= 4, Dc = 1. 610 g/cm3, μ= 3. 676 mm-1, F(000) = 696, T= 296K, R=0. 0269 for 1577 observed data. C15 H20 N4O4Se (2), Mr = 399. 31, space groupP212121, a=13. 849(5), b=4. 936(5), c=24. 942(5) A, V= 1705(1) A s, Z=4,Dc= 1. 566g/cm3, μ= 3. 230 mm-1 F(000) =816, T= 296K, R=0. 0856 for 3442observed data.