Adenine‐Based Coordination Polymers: Synthesis, Structure, and Properties

Abstract

A solvothermal reaction of metal nitrate (M = Zn, Cd), cyclohexanedicarboxylic acid, and adenine resulted in the isolation of three new coordination polymers, [Zn4(1,4‐CHDA)2.5(ad)3·2H2O] 7H2O 2DMA (CHDA = cyclohexane dicarboxylic acid, ad = adenine, DMA = dimethylacetamide), I, [Cd3(1,4‐CHDA)2(ad)2·H2O], II, [Cd(1,2‐CHDA)(9‐HEA)·H2O] 4H2O [9‐HEA = 9‐(2‐hydroxyethyl)adenine], III. Single‐crystal structural studies show that compounds I and II have three‐dimensional structures whereas III has a two‐dimensional one. The formation of a Cd8 macrocycle in II, based on a polyhedral arrangement, appears to be new. In all the compounds, the amino group of the adenine appears to be free and can be utilized for the detection of explosives such as nitrophenol, dinitrophenol, and trinitrophenols. The hydroxyl nitro aromatics appears to have a much stronger influence on the luminescence behavior of the compounds with very low detection limits. This, in fact, provides a new opportunity for exploring these compounds for the detection of harmful nitro aromatics in solution. The present compounds also exhibit considerable sensitivity towards metal ion detection, especially Fe2+/Fe3+, Cr3+, Ag+, and Hg2+ ions in solution. Base‐catalyzed Knoevenagel condensation studies exhibit good conversion and selectivity.

Dicopper(II)-EDTA Chelate as a Bicephalic Receptor Model for a Synthetic Adenine Nucleoside

“…To emphasize the relevance of the metal chelate-nucleoside molecular recognition in compound 1 reported here, it is worth comparing our results to some structural aspects concerning the polymer {Cd(µ 2 -(cis-1,2-chdc)(µ 2 -N1,N7-9heade) (H 2 O)]·4H 2 O} n (cis-1,2-H 2 chdca is the cis-cyclohexane-1,2-dicarboxylicacid, and cis-1,2-chdc its divalent anion) [ 15 ]. In this Cd(II) compound, the main driver causing its polymerization seems to be the utilization of the cis -1,2-chdc isomer.…”

“…In this context, significant advances have been made from crystal structures of a variety of ternary copper(II) complexes that bind acyclovir (acv) as coligand (see [ 12 ] and references therein). In these connections, we regard some metal complexes as receptors for the synthetic nucleoside N9-(2-hydroxyethyl)adenine (hereafter 9heade, Scheme 1 ), where the metal center is also linked to donor atoms of the coligands able to act as H-acceptors (O or Cl) atoms [ 13 , 14 , 15 , 16 ].…”

“…Interestingly, certain in vitro inhibitory effects of tumor cells to its 2′-phosphorilated form were reported [ 21 ], suggesting that such biological activities require the in vivo O-phosphorylation of its pseudo sugar -O(ol) H group. The structural knowledge of metal complexes with 9heade [ 13 , 14 , 15 , 16 ] strongly suggests that its preferred donor atom is N7 and that the N-basicity order for 9heade is N1 > N7 > N3 > >N6 (exocyclic) c. It is also clear that N7 is the preferred donor atom of 9heade, as supported by the crystal structures of various mixed-ligand complexes with Co(II) [ 15 ] Zn(II) [ 13 , 16 ], Cu(II) [ 13 ] or Cd(II) [ 14 ]. In addition, the bridging mode Cd 2 -µ-N1,N7(9heade) is documented for a Cd(II) coordination polymer [ 15 ].…”

“…The structural knowledge of metal complexes with 9heade [ 13 , 14 , 15 , 16 ] strongly suggests that its preferred donor atom is N7 and that the N-basicity order for 9heade is N1 > N7 > N3 > >N6 (exocyclic) c. It is also clear that N7 is the preferred donor atom of 9heade, as supported by the crystal structures of various mixed-ligand complexes with Co(II) [ 15 ] Zn(II) [ 13 , 16 ], Cu(II) [ 13 ] or Cd(II) [ 14 ]. In addition, the bridging mode Cd 2 -µ-N1,N7(9heade) is documented for a Cd(II) coordination polymer [ 15 ]. Interestingly, in the crystal of {[Cu(gg)(9heade)(H 2 O)·Cu(gg)(μ 2 -9heade)]·8H 2 O} n (gg = glycylglycinate(2-) anion), both the unidentate N7 and the bridging µ-N7,O(ol) are operative, also revealing that its O(ol) atom (mimicking the O2′-furanosyl adenosine atom) can contribute to supra-molecular recognition phenomena [ 13 ].…”

Synthesis and characterization of a Bio-MOF based on mixed adeninate/tricarboxylate ligands and zinc ions

“…These class of materials might have applications in a variety of fields, such as gas separation, molecular adsorption, cation incorporation, and sensing [21,22]. Previous investigations explored the use of carboxylate [23][24][25][26][27][28] linkers in conjunction with adeninate in several coordination modes [17,29]. The reported bio-MOFs show great variations in porosity, stability, and adsorption of small molecules such as CO 2 .…”