Synthesis and crystal structure of alkaline-earth metal cryptates of a ligand derived from 2,6-diformyl-pyridine

Abstract

New alkaline-earth metal cryptates [ML](ClO₄)₂ · solvent (M = Ca²⁺, Sr²⁺, Ba²⁺; L = 1,4, 12,15,18,26,31,39,42,43,44-undecaazapentacyclo-[13.13.13.1^6,10.1^20,24.1^33,37]-tetratetraconta-4, 6, 8, 10(44), 11,18,20,22,24(43),25,31,33,35,37(42),38-pentadecaene) were synthesized by [2 + 3] template condensation of tris(2-aminoethyl)amine with 2,6-diformylpyridine and characterized by physical methods. The crystal structure of the calcium cryptate was determined. The central atom is nine coordinate with three pyridyl and six imino nitrogen atoms. The coordination polyhedron can be described as slightly distorted tricapped trigonal prism.

Keywords:

• Alkaline-earth metal
• Cryptate
• Crystal structure

Acknowledgements

The work was supported by the National Natural Science Foundation of China for the grant No. 20671075, the Education Office of Hubei Province, PR China for the research grant No. D200515004 and the Natural Science Foundation of Hubei Province, PR China for the research grant No. 2005ABA021.