(4,7,13,16,21,24-Hexaoxa-1,10-diazabicyclo[8.8.8]hexacosane)sodium perchlorate

Abstract

Key indicators: single-crystal X-ray study; T = 100 K; mean (Na-O) = 0.002 Å; disorder in main residue; R factor = 0.037; wR factor = 0.113; data-to-parameter ratio = 9.5.The title compound, [Na(C 18 H 36 N 2 O 6 )]ClO 4 , was isolated and crystallized to understand more fully the ligand's binding specificity to cations. The cation and anion reside at an intersection of crystallographic twofold and threefold axes. The carbon atoms in the cation are disordered over two positions in a 3:2 ratio, and the anion is equally disordered over two positions. The geometries of the cation and anion are typical. The compound packs in alternating sheets of discrete cations and anions stacked along the c axis, separated by a distance equal to one-sixth the length of the c axis.

Living in a Cage Is a Restricted Privilege

“…In order to guarantee full amine coordination, the ligand contracts its cavity, bringing the distance between tertiary nitrogen atoms to 5.55 Å . To do that, it profits from the well-established mechanism that involves the rotation by 40 of the triangle defined by the secondary amine nitrogen atoms of a tren subunit, with respect to triangle of the other tren subunit.…”

“…Thus, 2.1.1-crypt displays sharp peak Fig. 18 Top: Structures of alkali metal complexes of 2.2.2-crypt, 9 (hydrogen atoms omitted for clarity) [39][40][41][42]. Bottom: Torsion angles defined by the two triangles obtained by linking the two sets of three oxygen atoms.…”

“…Figure 18 shows the structures of the alkali metal complexes of 2.2.2-crypt, obtained from X-ray diffraction studies on crystalline salts [39][40][41][42]. First, it is clear that the low stability of the Li + complex depends upon the circumstance that the smallest alkali metal ion is lost in the cavity and misses the interaction with an oxygen atom and with one tertiary amine group.…”