The synthesis and characterization of a new (E, E)-dioxime, its complex formations of the macrobicyclic group, and conformational analysis of the ligands

Abstract

In this study, 19-nitro-6,7,15,16,23,24-hexahydro-13H,26H-14,25-propanotribenzo-[b,i,o] [1,4,11,14,7,18] tetraoxadiazacycloicosine (3) was synthesized using 6,7,8,9,10,11,17,18-octahydro-5H-dibenzo[e,n][1,4]dioxa[8,12]diazacyclopentadesine (1) and 4-nitro-1,2-bis(2-iodoethoxy)benzene (2) as the starting compounds. Macrobicyclic amine 4 was synthesized by reaction of an aromatic nitro compound with hydrazine hydrate (100%) and palladium (10%)-activated carbon in n-butanol. N¹,N²-di-6,7,15,16,23,24-hexahydro-13H,26H-14,25-propanotribenzo[b,i,o][1,4,11,14,7,18]tetraoxadiazacycloicosin-19-yl-N′¹,N′²-dihydroxyethane-diimidamide vic-dioxime (6) was synthesized by reaction of cyanogen-di-N-oxide in CH₂Cl₂, which was obtained from (E, E)-dichloroglyoxime and an aqueous solution of Na₂CO₃ (0.1 N) with 4. Mononuclear Ni(II), Co(III), and Cu(II) complexes, 7, 9, and 10, were synthesized by reaction of vic-dioxime with NiCl₂·6H₂O, CoCl₂·6H₂O, and CuCl₂·2H₂O, respectively. -Capped mononuclear Ni(II) complex 8 was synthesized by reaction of boron-trifluoride diethyl etherate with mononuclear nickel(II) complex 7 in acetonitrile. The structures of new compounds were determined by elemental analysis, ¹H-NMR, ¹³C-NMR, IR, mass spectroscopic data, and thermal methods (TG/DTA). The conformational analysis of the ligands was performed using DFT and AM1 methods.

Keywords:

• vic-Dioxime
• Macrobicyclic compound
• Mononuclear complex
• Host–Guest compounds
• BF₂ ⁺-Capped complex

Acknowledgments

This study was supported by the Research Fund of Karadeniz Technical University, Project No. 2006.111.002.1 (Trabzon-Turkey).