Isolation and structure of an 18-membered macrocycle containing two diselenide linkages and its precursor.

The structures of the 18-membered diselenide-linked macrocycle 10,27-di-tert-butyl 11,28-dioxo-2,3,19,20-tetraselena-10,12,27,29-tetraazapentacyclo[28.4.0.04,9.013,18.021,26]tetratriaconta-1(30),4(9),5,7,13,15,17,21,23,25,31,33-dodecaene-10,27-dicarboxylate, C36H34N4O6Se4, and its precursor di-tert-butyl 2,2'-[diselane-1,2-diylbis(2,1-phenylene)]dicarbamate, C22H28N2O4Se2, are reported. The precusor to the macrocycle contains two tert-butyl phenylcarbamate arms connected to a diselenide group, with Se-C and Se-Se bond lengths of 1.914 (4) and 2.3408 (6) Å, respectively. The macrocycle resides on a crystallographic center of inversion in space group P-1 with one molecule in the unit cell (Z' = 1/2). It contains an 18-membered macrocyclic ring with two diselenide linkages. In this macrocycle, there are two free and two protected amino groups.