Crystal Structure of (2.2.2-Cryptand)lithium Perchlorate

Abstract

(2.2.2-Cryptand)lithium perchlorate [Li(2.2.2-Crypt)]⁺ClO^– ₄ (I) is prepared and characterized by X-ray structural analysis. Structure I (space group P2₁2₁2, a = 10.149 Å, b = 13.475 Å, c = 8.580 Å, Z = 2) is solved by the direct method and refined anisotropically by the full-matrix least-squares method to R = 0.056 for 2312 reflections (CAD4 automated diffractometer, λMoK _α). Crystal of complex I is built of [Li(2.2.2-Crypt)]⁺ complex cations of the host–guest type and randomly disordered ClO^– ₄ anions. Both ions are located on the twofold crystallographic axes. The Li⁺ cation, which is also randomly disordered about the 2 axis, is coordinated by the N atom and five O atoms from eight heteroatoms (2N + 6O) of the cryptand. Two Li–O and one Li–N bonds are noticeably elongated. The Li⁺ cation forms irregular six-vertex coordination polyhedron.