Preparation and Structural Characterization of a Diaza 21-Crown-7 Ether Complex With Barium Picrate - (3,6,9,12,15-Pentaoxa-26,29-Diazatetracyclo[15.8.4.020,28.023,27]-Nonaco Sa-17,19,21,23,25(1),26,28-Heptaene-2,16-Dione)Barium(II) Picrate

The synthesis, characterization and crystal stucture of the title complex is reported. The triclinic crystals belong to the space group Pī with a 12.726(5), b 14.284(5), c 11.094(5)Ǻ, α 95.76(5),β 93.42(4), γ 88.66(5) and Z 2. Refinement with 5365 diffractometer data measured with Cu Kα radiation converged at R 0.096. The barium ion is coordinated by a diaza 21-crown-7 ether ligand , which incorporates a phenanthroline moiety, and by two bidentate picrate anions, and thus has 11-coordination. The Ba -O bonds range from 2.62(1) to 3.02(1)Ǻ and the Ba -N bonds have lengths of 3.00(1) and 3.05(1)Ǻ. Disorder is evident in the aliphatic chain of the polyether and, apart from the orientation about a C-O bond in the disordered segment of the chain, the angles about the C-O and C-C bonds define gauche and anti conformations respectively.