A study on some alkaline earth metal cryptates - Synthesis, characterization, crystal structure and solution structure

Three alkaline earth metal cryptates (Barium(II), Strontium(II), Calcium(II )) were synthesized by (2+3) template condensation of tris(3-aminopropyl)am ine with 2,6-diformylpyridine and characterized by some physical methods. T he solution structure of [BaL](2+) (L=cryptand) was studied by electrospray mass spectrometry, H-1-C-13 NMR and molecular dynamics method based on ana lysis of H-1 NMR NOE spectrum. The crystal structure presents a tricapped t rigonal prism structure in which barium(II) is enclosed within the macrobic ycle and is nine-coordinated by six imino nitrogen atoms and three pyridyl nitrogen atoms. (C) 1999 Elsevier Science Ltd. All rights reserved.