The crystal and molecular structure of 1α,9β-Dichloro-2,2,10,10-tetramethoxy[2,2](2,6)pyridinophane

Abstract

Crystals of the title compound, C₁₈H₂₀Cl₂N₂O₄, are monoclinic, a 14.706(1), b 17.168(1), c 7.269(1) Ǻ, β 92.72(1)°, space group P2₁/c with Z = 4. The structure was solved from diffractometer data by direct methods. Block-diagonal least-squares refinement converged at R 0.037, R_w 0.045 for 2103 reflections with I ≥ 3σ(I) which had been corrected for absorption (μ 34.0 cm^-1). The asymmetric unit is comprised of two independent half-molecules, each molecule being centrosymmetric. The pyridine rings are distorted from planarity, with a maximum deviation of 0.10 Ǻ at the nitrogen atoms, as a consequence of the short intramolecular N...N contacts of 2.476(4) and 2.473(5) Ǻ.