Synthesis and X-ray crystal structure of a tetracyclic gem-cis- bis(aminal) formed from N,N'-bis(2-aminophenyl)ethylenediamine and 1,10-phenanthroline-5,6-dione
Barry Coyle,a Malachy McCann,*a Vickie McKee,b and Michael Devereuxc
aChemistry Department, National University of Ireland Maynooth, Maynooth, Co. Kildare, Ireland, bChemistry Department, Loughborough University, Loughborough, Leics., LE11 3TU, UK and cDublin Institute of Technology, Cathal Brugha Street, Dublin, Ireland
E-mail:
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Dedicated to Professor M. Anthony McKervey
(received 27 Feb 03; accepted 14 Apr 03; published on the web 18 Apr 03)
Abstract
The condensation reaction of 1,10-phenanthroline-5,6-dione with N,N'-bis(2- aminophenyl)ethylenediamine in a 1:1 molar ratio produces the tetracyclic gem-cis-bis(aminal) 7a,12c-(2,2'-bipyridin-3,3'-diyl)-1,2,7a,12c-tetrahydro-7H,8H-2a,7,8,12b- tetraazacyclopenta(fg)tetracene methanol (1:1) (1) (Figure 1). The X-ray crystal structure of (1)·MeOH (Figure 3) shows the molecule to be non-planar and chiral, and comprising three six- membered rings and one five-membered ring fused onto the back of a bipyridine moiety. Reaction of the dione with selected non-aromatic polyamines affords only 1,10-phenanthroline- 5,6-diol.
Keywords: Bipyridine, 1,10-phenanthroline-5,6-dione, N,N'-bis(2- aminophenyl)ethylenediamine, gem-cis-bis(aminal), 7a,12c-(2,2'-bipyridin-3,3'-diyl)-1,2,7a,12c- tetrahydro-7H,8H-2a,7,8,12b-tetraazacyclopenta(fg)tetracene methanol (1:1), X-ray structure.
Introduction
Our current interest in 1,10-phenanthroline and its metal complexes centers on the in vitro anti- fungal activities of this class of compound.1,2. More recently, we have found that 1,10- phenanthroline-5,6-dione and its N,N'-chelated Cu(II) and Ag(I) complexes exhibit a marked improvement in ability to inhibit the growth of the pathogenic fungus Candida albicans in comparison to their 1,10-phenanthroline analogues.3 In an effort to further enhance the anti- fungal activity it was decided to attempt to build an N4 macrocycle onto the back of 1,10- phenanthroline-5,6-dione, the resulting macrocyclic cavity having the ability to incorporate a
