Synthesis, complex formation, spectral and crystallographic investigationsof new crown ethers containing recognition site for sodium. Part V

The monotopic crown ether ligands (5 and 6) and their sodium perchlorate co mplexes (5a and 6a) have been synthesized. The crystal structure of (5) has been determined, which contains 1 mol of water molecule. Compound (5) crys tallizes in the monoclinic space group C2/c with a = 39.324(8), b = 8.011(1 ), c = 16.877(4) Angstrom, beta = 107.61(2)degrees, V = 5067.5(2) Angstrom (3), Z = 8 and D-calc = 1.289 g m(-3). The relative macrocyclic inner hole size, estimated as twice the mean dista nce of the donor atoms from their centroid is approximately 1.68 Angstrom. The phenazone and benzo crown ether precursors about C=N imine bond are in anti (E) configuration. The C=N imine bond length and C=N-C bond angle are 1.270(3) Angstrom and 120.4(2)degrees, respectively. Compounds (6) and (6a) are in phenol-imine forms as supported by H-1-NMR and UV-visible data. (C) 2001 Elsevier Science B.V. All rights reserved.