Bull. SOC. Chim. Belg. vo1.93/n0 2/1984 THE CRYSTAL STRUCTURE OF THE CYCLIC PENTAMER OF 1-E-BUTYLAZIRIDINE Arshad zyxwvutsrq MUNIR, William H. DALY, Frank R. FRONCZEK Chemistry Department, Louisiana State University, Baton Rouge, LA 70803, U.S.A. and Eric J. GOETHALS Laboratory of Organic Chemistry,Rijksuniversiteit-Gent, Krijgslaan 281 (S-41, 8-9000 GENT, BELGIUM Received zyxwvutsrq : zyxw 05/12/1963 - Accepted : Q2/Q3/1984 1Wl”RODUCTION. Protonic acid initiated polymerization of 1-s-butylaziridine produces A crystalline cyclic pentamer 1,~,7,10,13-penta-~-butyl-l,4,7,10,13-penta- azacyclopentadecane, as a by-product‘’). macrocycles is extensive; few of them contain five nitrogen atoms(2), and none are saturated pentaazacyclic amines. Thus, we felt it to be of interest to determine the crystal Structure of this unusual compound. Of particular in- terest are the relative orientations of the nitrogen lone pairs and the con- formation of the fifteen-membered ring. While the literature of polyaza- RESULTS. The structure of the cyclic pentamer is illustrated in Figure 1; coordi- nates are given in Table 1. cormon plane with average N...N distance in the distorted pentagon of 3.70 Jt. The distortion from coplanarity is best described as a twist towards the “half chair” conformation, in which N1 and N5 lie on opposite aides of the plane formed by the other three nitrogen atoms. Distances of all ring atoms from the best plane of the nitrogen atoms are given in Table 2. substituents are directed outward from the center of the molecule, the N lone pairs point approximately normal to the best plane of the five N atoms, and methylene H atoms are directed inward towards the central portion of the mole- cule. Distances from the midpoint of the N pentagon to H atoms indicate that no cavity exists in the molecule in the solid state conformation. Six ring H atoms are within 2.5 A of this point, of which four are within 1.7 A. The five nitrogen atoms lie within 0.85 Jt of a The E -butyl Bond distances and angles are linted in Tables 3 and 4. Of particular - 133 -