The reaction in water of the
N-benzyli
minodiacetate-copper(II)chelate ([Cu(NBzIDA)]) and the adenine:thy
mine base pair co
mplex(AdeH:ThyH) with a Cu/NBzIDA/AdeH/ThyH
molar ratio of 2:2:1:1yields [Cu
2(NBzIDA)
2(H
2O)
2(
mages/entities/
mgr.gif">-N7,N9-Ade(N3)H)]·3H
2O and freeThyH. The co
mpound has been studied by ther
mal, spectral, andX-ray diffraction
methods. In the asy
mmetric dinuclear co
mplexunits both Cu(II) ato
ms exhibit a square pyra
midal coordination,where the four closest donors are supplied by NBzIDA in a
mer-tridentate confor
mation and the N7 or N9 donors of AdeH, whichis protonated at N3. The
mages/entities/
mgr.gif">-N7,N9 bridge represents a newcoordination
mode for nonsubstituted AdeH, except for so
meadeninate(1-)-[
methyl
mercury(II)] derivatives studied earlier. Thedinuclear co
mplex is stabilized by the Cu-N7 and Cu-N9 bondsand N6-H(exocyclic)···O(carboxyl) and N3-H(heterocyclic)···O(carboxyl) interligand interactions, respectively. The structure ofthe new co
mpound differs fro
m that of the
mononuclear co
mpound[Cu(NBzIDA)(Ade(N9)H)(H
2O)]·H
2O, in which the unusual Cu-N3(AdeH) bond is stabilized by a N9-H···O(carboxyl) interligandinteraction and where alternating benzyl-AdeH inter
molecular
mages/gifchars/pi.gif" BORDER=0 >,
mages/gifchars/pi.gif" BORDER=0 >-stacking interactions produce infinite stacked chains. The possibilityfor ThyH to be involved in the
molecular recognition between [Cu(NBzIDA)] and the AdeH:ThyH base pair is proposed.