Conformational studies of dibenzo-30-crown-10 complexes. Syntheses and crystal structures of potassium and ammonium hexafluorophosphate complexes

Crown ether complexes formed by the dibenzo-30-crown-10 (DB30C10) with pota ssium and ammonium hexafluorophosphate have been prepared and their crystal structures have been determined by single crystal X-ray analyses. The pota ssium complex (compound 1) consists of [K(DB30C10)](+) cation and PF6- anio n. Crystals are monoclinic, space group P2/n, with a = 11.9106(3), b = 9.83 82(5), c = 14.3062(3) Angstrom, beta = 97.581(3)degrees, V = 1661.7(1) Angs trom (3), D-c = 1.440 g cm(-3), Z = 4, R = 0.0675 for 2528 unique observed reflections. The potassium atom is coordinated to the ten oxygen atoms of t he crown ligand at the distance from 2.859(3) to 2.930(3) Angstrom. The amm onium complex (compound 2) has also 1:1 crown-cation ratio. Crystals are mo noclinic, space group P2(1)/n, with a = 12.5061(6), b = 19.3724(5), c = 14. 2203(9) Angstrom, beta = 120.476(5)degrees, V = 3363.8(3) Angstrom (3), D-c = 1.501 g cm(-3), Z = 4, R = 0.0677 for 4172 unique observed reflections. The ammonium cation is completely enclosed with crown oxygen atoms forming seven hydrogen bends. The conformation of previously reported dibenzo-30-cr own-10 complexes with potassium salts were investigated using polar coordin ate maps.