Adenine Complexes Research Articles

Complexes of Copper(II) and Adenine at Various pH: Synthesis and Characterization

The coordination of Cu(II) ion with purine base is pH dependent and versatile. This study describes the synthesis, structuralcomponents and coordination behavior of Cu(II) with adenine. Three complexes of Cu(II) with adenine have been preparedat different pH in aqueous solution and ambient conditions. All synthesized complexes are polycrystalline solids of variouscolors, air-stable and partially soluble in polar solvents. The complexes were characterized by numerous analytical techniques including compositional analyses, Fourier transform infrared and UV-visible analyses, and thermal investigation. The elemental analyses of the complexes established their chemical composition as [Cu(adeninium)Cl3], [Cu(adenine)(H2O)Cl2] and [Cu(H2O)2(adeninato)2]. Analytical results suggest that the adenine nucleobase could act as a cationic (pH: 5), or a neutral (pH: 7), or an anionic (pH: 8) monodentate ligand in pH facilitated aqueous solution. In the structure, the purine moiety, chloride ion and aqua groups are situated around the copper(II) center is basically in a tetrahedral arrangements. Protonation or deprotonation of the adenine and intramolecular interligand hydrogen bond assisted the pH dependent versatile coordinating behavior of purine base. Dhaka Univ. J. Sci. 72(2): 84-90, 2024 (July)

Nickel and Oxo-Vanadium Complexes of Adenine on Modified Mesoporous MCM-41 as Chemoselective, Efficient, and Reusable Catalysts in the Oxidation of Sulfides and Oxidative Coupling of Thiols.

A highly efficient superior catalyst of Ni (II) and VO (IV) metal complexes supported on MCM-41 has been synthesized and developed for chemoselective oxidation of sulfides to sulfoxides and oxidative coupling of thiols to their corresponding disulfides using H2O2 as a green and efficient procedure. All sulfoxides and disulfides were obtained in short reaction times with excellent yields. The over-oxidation of sulfides or thiols was not observed and all products were synthesized in high purity. These catalysts could be recovered and reused several times without any significant loss in their catalytic activity. Compared to the old catalysts in the literature, these catalysts showed better activity and selectivity for the synthesis of sulfoxide and disulfide derivatives, which shows the novelty of this work. At first, the mesoporous MCM-41 was synthesized, and further, its surface was modified by (3-chloropropyl)-triethoxysilane (CPTES). Then, the modified MCM-41 (nPrCl-MCM- 41) was functionalized by adenine. In the next step, the functionalized MCM-41 (6AP-MCM- 41) was used as support for the immobilization of nickel and oxo-vanadium as final catalysts (Ni-6AP-MCM-41 or VO-6AP-MCM-41). The structure and properties of these catalysts have been identified by XRD, SEM, TGA, FT-IR, and AAS spectral analyses. These catalysts were used in the chemoselective oxidation of sulfides and oxidative coupling of thiols. These complexes catalyzed all reactions well at room temperature. According to the results obtained, the hydroxyl groups of some derivatives, including 2-(methylthio) ethanol or 2,2-(phenylthio) ethanol, remained unchanged during the reaction. The method has been found to possess the advantages of low cost, high efficiency, high yields, recovery, and reusability for several runs without significant loss in the catalytic activity.

Enhanced degradation of tetracycline with zinc-based adenine-derived P, N co-doped carbon via peroxydisulfate activation

In this study, a P, N co-doped carbon with excellent adsorption and peroxydisulfate (PDS) catalytic activity based on zinc-based adenine complex (Zn-Ade) derived has been designed and fabricated via a facile two-step pyrolysis strategy. Under the optimized conditions, the synthesized phosphorus and nitrogen co-doped carbon (PNC-4, 4 is the mass ratio of KH2PO4 to pristine nitrogen-doped carbon) has a high graphitic N and pyrrolic N and exhibited excellent catalytic activity in PDS activation. A small amount of PNC-4 (0.05 g/L) could remove about 92.44 % of TC within 80 min when the initial tetracycline (TC) concentration was 20 mg/L (PDS = 0.1 g/L; initial pH = 5.71), which could be attributed to the accelerated electron transfer and large adsorption capacity of PNC-4. The adsorption of TC on PNC-4 was chemisorption and the maximum theoretical capacity of adsorption (qmax) was 500.577 mg/g. The results of reactive oxygen species (ROS) capture experiments and electrochemical characterization confirmed that TC was oxidized mainly through electron transfer mechanism. Furthermore, the reaction rate constant (k) was significantly positively correlated with the graphitic N and pyrrolic N contents and weakly positively correlated with the defects, respectively. These findings demonstrated that graphitic N and pyrrolic N enhanced PDS activation and oxidized TC via the electron transfer pathway. Finally, the results of toxicity assessment showed that the toxicity of the intermediates were significantly reduced after TC degradation. This study not only propelled the mechanistic understanding of the collaborative contribution of active sites to PDS activation, but also offered a new strategy for the design of bifunctional carbon materials for adsorption and catalysis.

The pathological mechanisms and novel therapeutics for Leber's hereditary optic neuropathy.

Optic neuropathies were estimated to affect 115 in 100,000 population in 2018. Leber's Hereditary Optic Neuropathy (LHON) as one of such optic neuropathy diseases that was first identified in 1871 and can be defined as a hereditary mitochondrial disease. LHON is associated with three mtDNA point mutations which are G11778A, T14484, and G3460A that affect the NADH dehydrogenase subunits of 4, 6, and 1, respectively. However, in most cases, only one point mutation is involved. Generally, in manifestation of the disease, there are no symptoms until the terminal dysfunction in the optic nerve is observed. Due to the mutations, nicotinamide adenine dinucleotide (NADH) dehydrogenase or complex I is absent and thus ATP production is stopped. This further causes the generation of reactive oxygen species and retina ganglion cells apoptosis. Aside from the mutations, there are several environmental factors such as smoking and alcohol consumption that can be pointed out as the risk factors of LHON. Nowadays, gene therapy has been intensively studied for LHON treatment. Disease models using human induced pluripotent stem cells (hiPSCs) have been utilized for LHON research.

Molecular Docking, DFT, and Antibacterial Activity Study of a Newly Synthesized Mixed Ligand Complex of Co(II), 1,10-Phenanthroline, Adenine and Acetamide

Molecular Docking, DFT, and Antibacterial Activity Study of a Newly Synthesized Mixed Ligand Complex of Co(II), 1,10-Phenanthroline, Adenine and Acetamide

Theoretical aspects of cooperativity and hydrogen bond in complexes of adenine and two formaldehyde molecules

AbstractIn the present work, we use quantum chemical calculations to investigate the strength, origin and role of hydrogen bonds as well as their cooperativity in complexes of adenine with two formaldehyde molecules. Eight stable structures of complexes are determined on potential energy surface at the B3LYP/aug‐cc‐pVDZ level of theory. The interaction energies of complexes with ZPE and BSSE corrections range from ‐4.45 to ‐9.45 kcal.mol‐1. The NBO and AIM analyses indicate that the strength of complexes is mainly governed by the N‐H‧‧‧O hydrogen bonds predominating O=C‧‧‧O and C‐H‧‧‧O/N intermolecular interactions. Besides, the C‐H‧‧‧O/N contacts are blue shifting hydrogen bonds, while the red shift of N‐H stretching frequency occurs in N‐H‧‧‧O hydrogen bonds in the complexes investigated. Noticeably, it is found that the positive cooperativity makes an increase in the complex stability and the C‐H blue shift of stretching frequency in C‐H‧‧‧O hydrogen bonds upon complexation.

Reverse and Forward Electron Flow-Induced H2O2 Formation Is Decreased in α-Ketoglutarate Dehydrogenase (α-KGDH) Subunit (E2 or E3) Heterozygote Knock Out Animals.

α-ketoglutarate dehydrogenase complex (KGDHc), or 2-oxoglutarate dehydrogenase complex (OGDHc) is a rate-limiting enzyme in the tricarboxylic acid cycle, that has been identified in neurodegenerative diseases such as in Alzheimer’s disease. The aim of the present study was to establish the role of the KGDHc and its subunits in the bioenergetics and reactive oxygen species (ROS) homeostasis of brain mitochondria. To study the bioenergetic profile of KGDHc, genetically modified mouse strains were used having a heterozygous knock out (KO) either in the dihydrolipoyl succinyltransferase (DLST+/−) or in the dihydrolipoyl dehydrogenase (DLD+/−) subunit. Mitochondrial oxygen consumption, hydrogen peroxide (H2O2) production, and expression of antioxidant enzymes were measured in isolated mouse brain mitochondria. Here, we demonstrate that the ADP-stimulated respiration of mitochondria was partially arrested in the transgenic animals when utilizing α-ketoglutarate (α-KG or 2-OG) as a fuel substrate. Succinate and α-glycerophosphate (α-GP), however, did not show this effect. The H2O2 production in mitochondria energized with α-KG was decreased after inhibiting the adenine nucleotide translocase and Complex I (CI) in the transgenic strains compared to the controls. Similarly, the reverse electron transfer (RET)-evoked H2O2 formation supported by succinate or α-GP were inhibited in mitochondria isolated from the transgenic animals. The decrease of RET-evoked ROS production by DLST+/− or DLD+/− KO-s puts the emphasis of the KGDHc in the pathomechanism of ischemia-reperfusion evoked oxidative stress. Supporting this notion, expression of the antioxidant enzyme glutathione peroxidase was also decreased in the KGDHc transgenic animals suggesting the attenuation of ROS-producing characteristics of KGDHc. These findings confirm the contribution of the KGDHc to the mitochondrial ROS production and in the pathomechanism of ischemia-reperfusion injury.

Cryogenic ion spectroscopy of adenine complexes containing alkali metal cations.

Cryogenic ion spectroscopy was used to characterize adenine complexes containing alkali metal cations (M+A, M = Cs, Rb, K, Na, and Li) produced by electrospray ionization. The ultraviolet (UV) photodissociation spectra of the complexes stored in a cryogenic ion trap exhibited well-resolved vibronic bands near their origin bands of the S0-S1 transition. The UV-UV hole-burning and infrared ion-dip spectra showed that all the M+A ions in the ion trap were single isomers of M+A7a, where the M+ ion was not bound to canonical 9H-adenine (A9) but bound to a rare tautomer, 7H-adenine (A7). Density functional theory calculations showed lower tautomerization barriers for M+A9 than for bare A9 in aqueous solution. We suggest that M+ ions not only play a catalytic role in the tautomerization of A9 to A7 but also increase the tautomerization yield by forming stable M+A7a isomers.

Environmentally Benign, Intrinsically Coordinated, Lithium-Based Solid Electrolyte with a Modified Purine as Supporting Ligand.

Bioinspired materials have become increasingly competitive for electronic applications in recent years owing to the environment-friendly alternatives they offer. The notion of biocompatible solid organic electrolytes addresses the issues concerning potential leakage of corrosive liquids, volatility and flammability of electrolyte solvents. This study presents a new intrinsically coordinated LiI adenine complex that exhibits electrical conductivity as a solid electrolyte capable of self-sustained supply of LiI ions. It exhibits conductivity through moisture-assisted LiI ion motion up to 373 K, and possibly by an ion-hopping mechanism beyond 373 K. This purine-derived solid electrolyte shows enhanced conductivity and transference number demonstrating the potential of purine-based ligands and their coordination complexes in interesting materials applications.

DNA interaction and anticancer evaluation of new adenine complexes in presence of N, N-donors as secondary chelate

This article describes the synthesis and spectroscopic characterization of several Pd(II), Pt(II), Ag(I) and Rh(III) complexes with multi-dentate adenine (Had) as primary ligand and 2,2′-bipyridyl (bpy), 1,10-phenanthroline (phen) as secondary ligand. In the complexes, adenine coordinates bidentately through cyclic N7 and NH2 {[M(L)(Had)]Cl2 (M(II) = Pd, Pt; L = bpy, phen)}; cyclic N3 and deprotonated N9 {[Pd(ad)2] and [M(ad)Cl(H2O)] (M(II) = Pd, Pt)} or N1 & N7 in {dimeric [Ag(Had)(NO3)]2}, and monodentate through cyclic N3 {[Rh(Had)3(H2O)3]Cl3}. The main goal of this study is to prepare new low toxic and effective anticancer metal-based molecules. The in vitro anticancer activity against the human breast cancer (MDA-MB231) and human ovarian cancer (OVCAR-8) cell lines was tested using selected Pt(II) and Pt(II) mixed ligand, Had-phen and Had-bpy, complexes, which are rich N-donors, in comparison to cisplatin as a reference. Moreover, CT-DNA-binding properties of some complexes were studied using circular dichroism (CD) spectroscopy. Moreover, intercalative CT-DNA binding capability was indicated.

Supramolecular Metal–Organic Framework for CO2/CH4 and CO2/N2 Separation

Supramolecular metal–organic frameworks (SMOFs) are emerging as a new family of porous materials. In this work, a SMOF, [Cu2(ade)4(H2O)2](SiF6)2 (SMOF-SIFSIX-1, ade = adenine) was successfully synthesized from the cationic complex of copper and adenine and hexafluorosilicate anions by a slow diffusion method and was demonstrated for trapping carbon dioxide in preference to methane and nitrogen. With one-dimensional pores of about 3.6 × 3.6 Å to induce their distinguishing interactions with the three components, SMOF-SIFSIX-1 exhibited excellent selective gas sorption behaviors for CO2/CH4 (50:50) and CO2/N2 (15:85) gas mixtures with ideal adsorbed solution theory selectivities of 21.1 and 131.7 at 273 K and 100 kPa pressure, respectively, outperforming most of reported hydrogen-bonded organic frameworks so far. Neutron powder diffraction and DFT-D calculations were also carried out to investigate the CO2 adsorption configuration on SMOF-SIFSIX-1a, which suggested that this framework catch CO2 due to “C···F” and “O···H” supramolecular interactions between CO2 molecules and SMOF-SIFSIX-1a. This study demonstrates that the rarely studied SMOF material shows promising potential in gas adsorption separation.

Adenine/Au complex-dependent versatile electrochemical platform for ultrasensitive DNA-related enzyme activity assay

We present a novel and simple versatile electrochemical platform for investigating some DNA-related enzymes activity based on Au(III)-coordinated adenine complex (noted as Adenine/Au complex). The synthesized Adenine/Au complex, which possesses good biocompatibility, active electrochemical performance and strong bio-affinity, enables the construction of electrochemical biosensor and further concurrently being exploited for probing DNA-related enzyme activity. The significant strategy is based on three favorable properties: the dazzling polymeric ability of terminal deoxynucleotidyl transferase (TdT); the strong adsorption interaction between TdT-yielded T-rich DNA with Adenine/Au complex; the unique electro-catalytic property of Adenine/Au complex. Here, the change in electrochemical response depends on the concentration of TdT or alkaline phosphatase (ALP), so the same novel electrochemical sensor for detecting TdT or ALP can be established with a lower detection limit. Nay, the two developed biosensors display high selectivity, good reproducibility, stability and applicability in inhibitor or real sample investigations. These results prove that the presented Adenine/Au complex gives new insight in multiple-functionally biosensing, further promoting the potential application of Adenine/Au complex-relevant nano-materials in clinical diagnosis.

An electrochemical sensor based on nitrogen doped carbon material prepared from nitrogen-containing precursors

In this work, a nitrogen doped carbon material (NDC) was prepared by using a copper adenine complex as precursor and applied to electrochemical sensing of Vitamin B2 (VB2). The experimental results show that the nitrogen doped carbon material is obtained after calcination at 650 °C under argon atmosphere, afterwards, which were characterized by X-ray diffraction (XRD), transmission electron microscope (TEM), fourier transform infrared (FT-IR), and electrochemical method. According to the XRD data, the product was a carbon material, and infrared data demonstrates that there are two kinds of carbonyl nitrogen combination, respectively, C-N and C = N combination of ways. Importantly, we used NDC to construct electrochemical biosensor to detect VB2 by differential pulse voltammetry (DPV). The linear range was 6 × 10-6 - 3.5 × 10-4 M (R=0.9962), the minimum detection limit was 5.4 × 10-6 M, and the sensitivity is better. Consequently, it has better sensing performance.

Ni(II)‐Adenine complex coated Fe3O4 nanoparticles as high reusable nanocatalyst for the synthesis of polyhydroquinoline derivatives and oxidation reactions

In the present study, Fe3O4 nanoparticles were prepared via simple and versatile procedure. Then, a novel and green catalyst was synthesized by the immobilization of Ni on Fe3O4 nanoparticles coated with adenine. The activity of this nanostructure compound was examined for the oxidation of sulfides, oxidative coupling of thiols and synthesis of polyhydroquinolines. The prepared catalyst was characterized by Fourier transform infrared spectroscopy (FT‐IR), scanning electron microscopy (SEM), energy‐dispersive X‐ray spectroscopy (EDS), inductively coupled plasma optical emission spectroscopy (ICP‐OES), X‐ray Diffraction (XRD), thermal gravimetric analysis (TGA), and vibrating sample magnetometer (VSM) measurements. This organometallic catalyst was recovered by the assistance of an external magnetic field from the reaction mixture and reused for seven continuous cycles without noticeable change in its catalytic activity.

Reactivity of nitrogen atoms in adenine and (Ade)2Cu complexes towards ribose and 2-furanmethanol: Formation of adenosine and kinetin

To explore the interaction of nucleosides and nucleobases in the context of the Maillard reaction and to identify the selectivity of purine nitrogen atoms towards various electrophiles, model systems composed of adenine or adenosine, glycine, ribose and/or 2-furanmethanol (with and without copper) were studied in aqueous solutions heated at 110°C for 2h and subsequently analyzed by ESI/qTOF/MS/MS in addition to isotope labelling techniques. The results indicated that ribose selectively formed mono-ribosylated N6 adenine, but in the presence of (Ade)2Cu complex the reaction mixture generated mono-, di- and tri-substituted sugar complexes and their hydrolysis products of mono-ribosylated N6 and N9 adenine adducts and di-ribosylated N6,9 adenine. Furthermore, the reaction of 2-furanmethanol with adenine in the presence of ribose generated kinetin and its isomer, while its reaction with adenosine generated kinetin riboside, as confirmed by comparing the MS/MS profiles of these adducts to those of commercial standards.

Metal Complexes of Mixed Nucleobases. Part I: Synthesis and Characterization of Copper(II), Zinc(II), Cadmium(II) and Mercury(II) Complexes of Adenine and Uracil

The complexes of Cu(II), Zn(II), Cd(II) and Hg(II) with adenine (AdeH) and uracil (UraH) have been synthesized and characterized by a combination of metal contents estimation, IR, UV-vis spectral data, thermogravimetric analysis (QSTG, TG and DSC) and magnetic susceptibility measurement. All the complexes are micro-crystalline, slightly soluble in water and decompose at high temperature. Both adenine and uracil deprotonated under experimental condition and then ligated to the metal ions as bidentate ligands through N(3) and N(9) of adeninato (Ade), and through N(3) and C(2)=O of uracilato (Ura) anions. On the basis of the metal contents, the complexes are formulated as [M(C5H4N5O)(C5H4N5)(H2O)2] [M = Cu(II), Zn(II) and Hg(II)] and [Cd(C5H4N5)(C4H3N2O2)(H2O)2].2H2O. The redox properties of copper and cadmium complexes were examined in aqueous solution by cyclic voltammetry. The voltammograms show quasi-reversible behavior for both the complexes. The X-ray powder diffraction study of the copper complex indicates that it is poorly crystalline in nature.
 Dhaka Univ. J. Sci. 64(2): 127-133, 2016 (July)

A new two-dimensional extended adenine and thiophenecarboxylate mixed-ligand zinc(II) complex: synthesis, structure, thermostability and luminescent properties.

The design and preparation of crystalline polymeric materials has attracted increasing attention due to their diverse applications as functional materials in gas storage, separation, catalysis, sensing and photoluminescence. The judicious selection of organic linkers is critical for varying the coordination behaviour of the metal ions and determining the overall characteristics of the networks. A new adenine-based Zn(II) coordination polymer, [Zn(C6H2O4S)(C5H5N5)]n or [Zn(tdc)(9H-ade)] (H2tdc is thiophene-2,5-dicarboxylic acid and ade is adenine), has been prepared hydrothermally and the crystal structure exhibits in its packing two-dimensional (4,4) grid sheets parallel to the ab plane, featuring two distinct square cavities delimited by the two types of ligands and the Zn(II) ions with the dimensions 6.6 × 6.6 and 10.2 × 10.2 Å (based on the Zn...Zn distance). The title complex shows enhanced photoluminescence at 378 nm compared to the free ligands, suggesting that the coordination of H2tdc or adenine to the metal centre effectively increases the rigidity of the ligands and reduces the energy loss by radiative decay of intraligand excited states.

Photoelectron spectroscopy of hexachloroplatinate-nucleobase complexes: Nucleobase excited state decay observed via delayed electron emission.

We report low-temperature photoelectron spectra of isolated gas-phase complexes of the hexachloroplatinate dianion bound to the nucleobases uracil, thymine, cytosine, and adenine. The spectra display well-resolved, distinct peaks that are consistent with complexes where the hexachloroplatinate dianion is largely intact. Adiabatic electron detachment energies for the hexachloroplatinate-nucleobase complexes are measured as 2.26-2.36 eV. The magnitudes of the repulsive Coulomb barriers (RCBs) of the complexes are all ∼1.7 eV, values that are lower than the RCB of the uncomplexed PtCl6 (2-) dianion as a result of charge solvation by the nucleobases. In addition to the resolved spectral features, broad featureless bands indicative of delayed electron detachment are observed in the 193 nm photoelectron spectra of the four clusters. The 266 nm spectra of the PtCl6 (2-) ⋅ thymine and PtCl6 (2-) ⋅ adenine complexes also display very prominent delayed electron emission bands. These results mirror recent results on the related Pt(CN)4 (2-) ⋅ nucleobase complexes [A. Sen et al., J. Phys. Chem. B 119, 11626 (2015)]. The observation of delayed electron emission bands in the PtCl6 (2-) ⋅ nucleobase spectra obtained in this work, as for the previously studied Pt(CN)4 (2-) ⋅ nucleobase complexes, is attributed to one-photon excitation of nucleobase-centred excited states that can effectively couple to the electron detachment continuum, producing strong electron detachment. Moreover, the selective, strong excitation of the delayed emission bands in the 266 nm spectra is linked to fundamental differences in the individual nucleobase photophysics at this excitation energy. This strongly supports our previous suggestion that the dianion within these clusters can be viewed as a "dynamic tag" which has the propensity to emit electrons when the attached nucleobase decays over a time scale long enough to allow autodetachment.

Electron Detachment as a Probe of Intrinsic Nucleobase Dynamics in Dianion-Nucleobase Clusters: Photoelectron Spectroscopy of the Platinum II Cyanide Dianion Bound to Uracil, Thymine, Cytosine, and Adenine.

We report the first low-temperature photoelectron spectra of isolated gas-phase complexes of the platinum II cyanide dianion bound to nucleobases. These systems are models for understanding platinum-complex photodynamic therapies, and a knowledge of the intrinsic photodetachment properties is crucial for characterizing their broader photophysical properties. Well-resolved, distinct peaks are observed in the spectra, consistent with complexes where the Pt(CN)4(2-) moiety is largely intact. Adiabatic electron detachment energies for the dianion-nucleobase complexes are measured to be 2.39-2.46 eV. The magnitudes of the repulsive Coulomb barriers of the complexes are estimated to be between 1.9 and 2.1 eV, values that are lower than for the bare Pt(CN)4(2-) dianion as a result of charge solvation by the nucleobases. In addition to the resolved spectral features, broad featureless bands indicative of delayed electron detachment are observed in the 193 nm photoelectron spectra of the four dianion-nucleobase complexes and also in the 266 nm spectra of the Pt(CN)4(2-)·thymine and Pt(CN)4(2-)·adenine complexes. The selective excitation of these features in the 266 nm spectra is attributed to one-photon excitation of [Pt(CN)4(2-)·thymine]* and [Pt(CN)4(2-)·adenine]* long-lived excited states that can effectively couple to the electron detachment continuum, producing strong electron detachment signals. We attribute the delayed electron detachment bands observed here for Pt(CN)4(2-)·thymine and Pt(CN)4(2-)·adenine but not for Pt(CN)4(2-)·uracil and Pt(CN)4(2-)·cytosine to fundamental differences in the individual nucleobase photophysics following 266 nm excitation. This indicates that the Pt(CN)4(2-) dianion in the clusters can be viewed as a "dynamic tag" which has the propensity to emit electrons when the attached nucleobase displays a long-lived excited state.

Heptacopper(II) and dicopper(II)-adenine complexes: synthesis, structural characterization, and magnetic properties

The syntheses, crystal structures, and magnetic properties of two new copper(II) complexes with molecular formulas [Cu7(μ2-OH2)6(μ3-O)6(adenine)6](NO3)2·6H2O (1) and [Cu2(μ2-H2O)2(adenine)2(H2O)4](NO3)4·2H2O (2) are reported. The heptanuclear compound is composed of a central octahedral CuO6 core sharing edges with six adjacent copper octahedra. In 2, the copper octahedra shares one equatorial edge. In both compounds, these basic copper cluster units are further linked by water bridges and bridging adenine ligands through N3 and N9 donors. All copper(II) centers exhibit Jahn–Teller distorted octahedral coordination characteristic of a d9 center. The study of the magnetic properties of the heptacopper complex revealed a dominant ferromagnetic intra-cluster interaction, while the dicopper complex exhibits antiferromagnetic intra-dimer interactions with weakly ferromagnetic inter-dimer interaction.