Carboxylate Donor Research Articles

Synthesis, characterization and adsorption of lead from water using 3-D metal carboxylate and nitrogen donor coordination polymer

Synthesis, characterization and adsorption of lead from water using 3-D metal carboxylate and nitrogen donor coordination polymer

Control over Anion Coordination on Pd(II), Cu(I), and Ag(I) with Regioisomeric Phosphine-Carboxylate Ligands.

The coordination of anionic donors is involved at various stages of catalytic cycles in transition-metal catalysis, but control over the spatial positioning of anions around a metal center is a challenge in coordination chemistry. Here we show that regioisomeric phosphine-carboxylate ligands provide spatial anion control on palladium(II) centers by favoring either κ2, cis-κ1, or trans-κ1 coordination of the carboxylate donor. Additionally, the palladium(II) carboxylates, which contain a methyl donor, upon protonation, deliver metal-alkyl complexes that feature a coordinated carboxylic acid. Such complexes can be considered as models for the minima that follow the concerted metalation-deprotonation transition state for C-H activation. The predictability of the coordination modes is further demonstrated on silver(I) and copper(I) centers, for which less common structures of mononuclear and dinuclear complexes can be obtained by using spatial anion control. Our results demonstrate the potential for spatial control over carboxylate anions in coordination chemistry.

Efficient synthesis of L-malic acid by malic enzyme biocatalysis with CO2 fixation

The malic enzyme (ME) catalyzes the synthesis of L-malic acid (L-MA) from pyruvic acid and CO2 with NADH as the reverse reaction of L-MA decarboxylation. Carboxylation requires excess pyruvic acid, limiting its application. In this study, it was determined that CO2 was the carboxyl donor by parsing the effects of HCO3– and CO2, which provided a basis for improving the L-MA yield. Moreover, the concentration ratio of pyruvic acid to NADH was reduced from 70:1 to 5:1 using CO2 to inhibit decarboxylation and to introduce the ME mutant A464S with a 2-fold lower Km than that of the wild type. Finally, carboxylation was coupled with NADH regeneration, resulting in a maximum L-MA yield of 77 % based on the initial concentration of pyruvic acid. Strategic modifications, including optimal reactant ratios and efficient mutant ME, significantly enhanced L-MA synthesis from CO2, providing a promising approach to the biotransformation process.

Altering relative metal-binding affinities in multifunctional Metallochaperones for mutant p53 reactivation

The p53 protein plays a major role in cancer prevention, and over 50% of cancer diagnoses can be attributed to p53 malfunction. p53 incorporates a structural Zn site that is required for proper protein folding and function, and in many cases point mutations can result in loss of the Zn2+ ion, destabilization of the tertiary structure, and eventual amyloid aggregation. Herein, we report a series of compounds designed to act as small molecule stabilizers of mutant p53, and feature Zn-binding fragments to chaperone Zn2+ to the metal depleted site and restore wild-type (WT) function. Many Zn metallochaperones (ZMCs) have been shown to generate intracellular reactive oxygen species (ROS), likely by chelating redox-active metals such as Fe2+/3+ and Cu+/2+ and undergoing associated Fenton chemistry. High levels of ROS can result in off-target effects and general toxicity, and thus, careful tuning of ligand Zn2+ affinity, in comparison to the affinity for other endogenous metals, is important for selective mutant p53 targeting. In this work we show that by using carboxylate donors in place of pyridine we can change the relative Zn2+/Cu2+ binding ability in a series of ligands, and we investigate the impact of donor group changes on metallochaperone activity and overall cytotoxicity in two mutant p53 cancer cell lines (NUGC3 and SKGT2).

Electrocatalysis of the Oxygen Reduction Reaction by Copper Complexes with Tetradentate Tripodal Ligands.

The tetradentate tripodal ligand scaffold is capable of supporting the expected geometries of the copper ion during the oxygen reduction reaction (ORR) catalysis. As such, we probed the reactivity of copper complexes with these types of ligands by electronically and structurally tweaking the tris(pyridin 2-ylmethyl)amine (tmpa) scaffold by progressively replacing the terminal pyridines with carboxylate donors. This work shows that systems with one carboxylato donor (bpg = bis(pyridin-2-ylmethyl)glycine), (bpp = (3-(bis(pyridin-2-ylmethyl)amino)propanoic acid)) are active in electrocatalyzing the homogeneous ORR under circumneutral aqueous conditions. Turnover frequencies in the range from 105 to 106 s-1, on par with that for Cu-tmpa under identical conditions, were obtained. It is noteworthy that the CuII/CuI redox potentials for the Cu-bpg, Cu-bpp, and Cu-tmpa systems in phosphate-buffered water (pH 7, under Ar) are similar at -0.409, -0.375, and -0.401 V vs Ag/AgCl, respectively. This is rationalized by the influence of the Lewis acidity of the copper ions on the water coligand. Corroborating this are pKa values for [Cu(tmpa)(H2O)]2+, Cu(bpg)(H2O)]+, and [Cu(bpp)(H2O)]+ of 6.6, 8.8, and 10.2, respectively. Thus, the overall charge of the solution species for all three complexes will be +1 at pH 7 and this will be an important determinant for the redox potentials and, in turn, the catalytic overpotentials, which are also similar. A cis carboxylato donor offers H-bonding possibilities for exogenous resting state water and intermediate hydroperoxo coligands. This is reflected by the higher pKa values for Cu-bpp and Cu-bpg compared with that for Cu-tmpa, with the Cu-bpp system furnishing the least strained H-bonding.

Spectroscopic, theoretical and computational investigations of novel benzo[b]thiophene based ligand and its M(II) complexes: As high portentous antimicrobial and antioxidant agents

The reaction of 3-chlorobenzo[b]thiophene-2-carbohydrazide with 4-(diethylamino) salicylaldehyde gave the new ligand; 3-chloro-N'-(4-(diethylamino)-2-hydroxybenzylidene)-benzo[b]thiophene-2-carbohydrazide. The Cu(II), Co(II), Ni(II), and Zn(II) complexes have been successfully prepared. The ligand and the complexes were characterized by analytical, FT-IR, 1H NMR, mass, UV–visible spectroscopy, molar conductivity, and magnetic susceptibility measurements. The FT-IR spectral data showed that the ligand adopted a tridentate fashion when binding with the metal ions via the nitrogen atoms of the imine (C = N), carboxyl (C = O), and phenolic oxygen (O–H) donor atoms. Density Functional Theory (DFT) estimations for the ligand at the DFT/B3LYP level via 6-31G++ (d, p) replicate the structure and geometry. Finally, HOMO and LUMO analyses were used for the charge transfer interface of the structure. Furthermore, molecular docking and ADME calculations were also performed to correlate and interpret the experimental results. The antimicrobial activity study illustrated enhancement in the activity of the free ligand upon complex formation, and the Cu(II) complex (MIC 25 µg mL−1) may be considered a promising antibacterial agent, and the Ni(II) and Zn(II) complexes (MIC 25 µg mL−1) as promising antifungal agents. Also, synthesized Cu(II) and Zn(II) metal complexes (MIC 3.125 µg mL−1) showed promising anti-TB activity against M. tuberculosis. Further, benzo[b]thiophene-based ligand and its metal complexes were evaluated for in vitro antioxidant activity, and in silico docking studies were carried out against Cytochrome c Peroxidase (PDB ID: 2X08).

Catalytic Hydrothermal Deoxygenation of Stearic Acid with Ru/C: Effects of Alcohol- and Carboxylic Acid-Based Hydrogen Donors.

Catalytic hydrothermal processing is a promising technology for the production of biofuels used in transportation to alleviate the energy crisis. An important challenge for these processes is the need for an external supply of hydrogen gas to accelerate the deoxygenation of fatty acids or lipids. It follows that in situ-produced hydrogen can improve process economics. This study reports on the use of various alcohol and carboxylic acid amendments as sources for in situ hydrogen production to accelerate Ru/C-catalyzed hydrothermal deoxygenation of stearic acid. Addition of these amendments significantly increases yields of liquid hydrocarbon products, including the major product heptadecane, from stearic acid conversion at subcritical conditions (330 °C, 14-16 MPa during the reaction). This research provided guidance for simplifying the catalytic hydrothermal process of biofuel production, making the production of the desired biofuel in one pot possible without the need for an external H2 supply.

Performance evaluation of phosphonium based deep eutectic solvents coated cerium oxide nanoparticles for CO2 capture

The critical challenge being faced by our current modern society on a global scale is to reduce the surging effects of climate change and global warming, being caused by anthropogenic emissions of CO2 in the environment. Present study reports the surface driven adsorption potential of deep eutectic solvents (DESs) surface functionalized cerium oxide nanoparticles (CeNPs) for low pressure CO2 separation. The phosphonium based DESs were prepared using tetra butyl phosphoniumbromide as hydrogen bond acceptor (HBA) and 6 acids as hydrogen bond donors (HBDs). The as-developed DESs were characterized and employed for the surface functionalization of CeNPs with their subsequent utilization in adsorption-based CO2 adsorption. The synthesis of as-prepared DESs was confirmed through FTIR measurements and absence of precipitates, revealed through visual observations. It was found that DES6 surface functionalized CeNPs demonstrated 27% higher adsorption performance for CO2 capturing. On the contrary, DES3 coated CeNPs exhibited the least adsorption progress for CO2 separation. The higher adsorption performance associated with DES6 coated CeNPs was due to enhanced surface affinity with CO2 molecules that must have facilitated the mass transport characteristics and resulted an enhancement in CO2 adsorption performance. Carboxylic groups could have generated an electric field inside the pores to attract more polarizable adsorbates including CO2, are responsible for the relatively high values of CO2 adsorption. The quadruple movement of the CO2 molecules with the electron-deficient and pluralizable nature led to the enhancement of the interactive forces between the CO2 molecules and the CeNPs decorated with the carboxylic group hydrogen bond donor rich DES. The current findings may disclose the new research horizons and theoretical guidance for reduction in the environmental effects associated with uncontrolled CO2 emission via employing DES surface coated potential CeNPs.

Sensitization Pathways in NIR-Emitting Yb(III) Complexes Bearing 0, +1, +2, or +3 Charges.

Yb(III) complexes of macrocyclic ligands based on 1,4,7,10-tetraazacyclododecane were synthesized. The ligands carried a carbostyril chromophore for Yb(III) sensitization, and carboxylate or carbamide donors for metal binding, forming complexes of 0, +1, +2, or +3 overall charge. The coordination geometry was little affected by the replacement of carboxylates with amides, as shown by paramagnetic 1H NMR spectroscopy. The Yb(III)/Yb(II) reduction potentials were dependent on the nature of the metal binding site, and the more positively charged complexes were easier to reduce. Carbostyril excitation resulted in Yb(III) luminescence in every complex. The residual carbostyril fluorescence quantum yields were smaller in complexes containing more reducible Yb(III) centers decreasing from 5.9% for uncharged complexes to 3.1-4.4% in +3 charged species, suggesting photoinduced electron transfer (PeT) from the antenna to the Yb(III). The relative Yb(III) luminescence quantum yields were identical within the experimental error, except for the +3 charged complex with fully methylated coordinating amides, which was the most intense Yb(III) emitter of the series in water. Quenching of the Yb(III) excited state by NH vibrations proved to limit Yb(III) emission. No clear improvement of the Yb(III) sensitization efficiency was shown upon faster PeT. This result can be explained by the concomitant sensitization of Yb(III) by phonon-assisted energy transfer (PAEnT) from the antenna triplet excited state, which was completely quenched in all of the Yb complexes. Depopulation of the triplet by PeT quenching of the donor singlet excited state would be compensated by the sensitizing nature of the PeT pathway, thus resulting in a constant overall sensitization efficiency across the series.

Anionic uranyl ion complexes with pyrazinetetracarboxylate: Influence of structure-directing cations

Pyrazine-2,3,5,6-tetracarboxylic acid (H4PZTC) has been used to synthesize three uranyl ion complexes under solvo-hydrothermal conditions and in the presence of additional cations as structure-directing agents. The complex [C(NH2)3]2[UO2(PZTC)]⋅2H2O (1) displays double ONO-chelation of uranyl, resulting in the formation of a monoperiodic coordination polymer, further association being provided by guanidinium and water hydrogen bonding. The PZTC4– ligand in [Co(en)3][UO2(PZTC)](NO3)⋅H2O (2) is bound to three uranyl cations, one of them ONO-chelated and the others bound to monodentate carboxylate donors, and the polymer formed is triperiodic with the ths topology. The ONO sites in the heterometallic complex [UO2Ag2(PZTC)] (3) are occupied by Ag+ cations, further carboxylate bonding to uranyl and Ag+ cations, as well as oxo bonding of uranyl to Ag+, resulting in the formation of an intricate triperiodic framework in which uranyl cations and PZTC4– alone give a triperiodic polymer with the lvt topology displaying double interpenetration, the Ag+ cations connecting the two networks into a single assembly.

Solvent Free Synthesis of Some Metal Complexes of Carboxylate and Nitrogen Donor Ligand

Solvent Free Synthesis of Some Metal Complexes of Carboxylate and Nitrogen Donor Ligand

Synthesis and characterization of chiral bidentate bis(N-heterocyclic carbene)-carboxylate palladium and nickel complexes

Complexes [Pd{(S)-NHCMes,R}2] (R = Me, 2a; iPr, 2b; iBu, 2c) and [Pd{(R)-NHCMes,Me}2] (2a’) were prepared by reaction of the corresponding imidazolium precursor [ImMes,R] (namely (S)–2-alkyl(3-mesityl-1H-imidazol-3-ium-1-yl)acetate, 1a-c, and (R)-2-methyl(3-mesityl-1H-imidazol-3-ium-1-yl)acetate, 1a’), with Ag2O and subsequent interaction with Pd(OAc)2, under appropriate conditions. Alternatively, complexes 2 were also obtained by treating compounds [ImMes,R], 1, with an in-situ prepared lithium diisopropylamide solution and then reaction with [Pd(OAc)2]. On the other hand, the nickel complex [Ni{(S)-NHCMes,iPr}2], 3b, was synthesized by the interaction of the complex [NiCp2] (Cp = η5-C5H5) with [ImMes,iPr], 1b, in THF. If this reaction was carried out in acetonitrile, a mixture of complex 3b and the cyclopentadienyl monocarbene complex [NiCp{(S)-NHCMes,iPr}], 4b, was obtained. Similarly to 2b, compound 3b was also prepared by the in-situ formation of the carbene [(S)–NHCMes,iPr]- and then reaction with [NiBr2(dme)] (dme = 1,2-dimethoxyethane). Complexes 2, 3 and 4 were obtained with good yields and fully characterized by analytical (HR-ESI and microanalysis), spectroscopic (IR, 1H and 13C NMR and polarimetry) and X-ray methods (2c). In the solid state, 2c is a square planar complex containing two [(S)-NHCMes,iBu]- ligands coordinated in a κ2-C,O fashion, where the carbene and carboxylate donors have the expected trans configuration. The existence of two possible conformers of complexes 2 and 3 was analyzed using DFT methods.

Effect of an aqueous copper gel electrolyte with cobalt metal organic framework based additive on performance of aqueous-dye-sensitized solar cells

A simple mono-dentate ligand substitution approach was studied to design three new potential tunable heteroleptic copper redox mediators with general formula [Cu (bnbip) (X)]1+/2+ where, bnbip is a tridentate ligand, (2,6-bis(1-(naphthalen-2-ylmethyl)-1H-benzo[d]imidazol-2-yl)pyridine), X = 4-tert-butylpyridine (tbp), 4-chloropyridine (cp) and 5-methoxy-1-(pyridin-4-yl)-1H-indole (mpi). Herein, copper mediator bearing bulky high donor ligand (mpi) reached best redox potential of 0.72 V vs NHE, which directly improves Voc and Jsc of the dye-sensitized solar cells (DSSC) devices because of its lower reorganization energy and driving force. A series of six aqueous gel electrolytes were prepared as G-1, G-2, G-3 (without additive) and G-4, G-5, G-6 (with Co-MOF additive) to analyze the role of three different heteroleptic copper redox couples and Co-MOF in aqueous gelrite polymer electrolytes. Impressively, electrolytes G-4, G-5 and G-6 affords higher PCE of 2.03, 2.12 and 3.42% under 1sun condition than electrolytes without additives, which proves the role of Co-MOF as an additive to reduce recombination process. This control in recombination occurred due to high interaction of repeating carboxylate donor groups of additive with TiO2 surface and Cu2+ ion of redox pair. The electrolyte material G-6 consists of Cu+1/+2[(bnbip)(mpi)] redox mediator, Co-MOF additive and aqueous geltrite polymer host obtained higher Jsc and PCE which were sustained via many aspects, such as high conductivity, larger charge, higher chemical capacitance, longer electron lifetime, a shift in the quasi-Fermi level of TiO2, lower recombination of electrons and fast dye regeneration.

Crystal structure of trans-di-aqua-(1,4,8,11-tetra-aza-undeca-ne)nickel(II) bis-(pyridine-2,6-di-carboxyl-ato)nickel(II).

The asymmetric unit of the title compound, trans-di-aqua-(1,4,8,11-tetra-aza-undecane-κ4 N 1,N 4,N 8,N 11)nickel(II) bis-(pyridine-2,6-di-carboxyl-ato-κ3 O 2,N,O 6)nickel(II) {[Ni(L)(H2O)2][Ni(pdc)2] where L = 1,4,8,11-tetra-aza-undecane (C7H20N4) and pdc = the dianion of pyridine-2,6-di-carb-oxy-lic acid (C7H3NO4 2-)} consists of an [Ni(L)(H2O)2]2+ complex cation and a [Ni(pdc)2]2- anion. The metal ion in the cation is coordinated by the four N atoms of the tetra-amine ligand and the mutually trans O atoms of the water mol-ecules in a tetra-gonally elongated octa-hedral geometry with the average equatorial Ni-N bond length slightly shorter than the average axial Ni-O bond [2.087 (4) versus 2.128 (4) Å]. The ligand L adopts its energetically favored conformation with five-membered and six-membered chelate rings in gauche and chair conformations, respectively. In the complex anion, the NiII ion is coordinated by the two tridentate pdc2- ligands via their carboxyl-ate and nitro-gen atom donors in a distorted octa-hedral trans-NiO4N2 geometry with nearly orthogonal orientation of the planes defining the carboxyl-ate rings and the average Ni-N bond length [1.965 (4) Å] shorter than the average Ni-O bond distance [2.113 (7) Å]. In the crystal, the NH donor groups of the tetra-amine, the carb-oxy-lic groups of the pdc2- anion and the coordinated water mol-ecules are involved in numerous N-H⋯O and O-H⋯O hydrogen bonds, leading to electroneutral sheets oriented parallel to the (001) plane.

Replaceability of Schiff base proton donors in light-driven proton pump rhodopsins

Many H+-pump rhodopsins conserve “H+ donor” residues in cytoplasmic (CP) half channels to quickly transport H+ from the CP medium to Schiff bases at the center of these proteins. For conventional H+ pumps, the donors are conserved as Asp or Glu but are replaced by Lys in the minority, such as Exiguobacterium sibiricum rhodopsin (ESR). In dark states, carboxyl donors are protonated, whereas the Lys donor is deprotonated. As a result, carboxyl donors first donate H+ to the Schiff bases and then capture the other H+ from the medium, whereas the Lys donor first captures H+ from the medium and then donates it to the Schiff base. Thus, carboxyl and Lys-type H+ pumps seem to have different mechanisms, which are probably optimized for their respective H+-transfer reactions. Here, we examined these differences via replacement of donor residues. For Asp-type deltarhodopsin (DR), the embedded Lys residue distorted the protein conformation and did not act as the H+ donor. In contrast, for Glu-type proteorhodopsin (PR) and ESR, the embedded residues functioned well as H+ donors. These differences were further examined by focusing on the activation volumes during the H+-transfer reactions. The results revealed essential differences between archaeal H+ pump (DR) and eubacterial H+ pumps PR and ESR. Archaeal DR requires significant hydration of the CP channel for the H+-transfer reactions; however, eubacterial PR and ESR require the swing-like motion of the donor residue rather than hydration. Given this common mechanism, donor residues might be replaceable between eubacterial PR and ESR.

Practical and Regioselective Synthesis of C-4-Alkylated Pyridines.

The direct position-selective C-4 alkylation of pyridines has been a long-standing challenge in heterocyclic chemistry, particularly from pyridine itself. Historically this has been addressed using prefunctionalized materials to avoid overalkylation and mixtures of regioisomers. This study reports the invention of a simple maleate-derived blocking group for pyridines that enables exquisite control for Minisci-type decarboxylative alkylation at C-4 that allows for inexpensive access to these valuable building blocks. The method is employed on a variety of different pyridines and carboxylic acid alkyl donors, is operationally simple and scalable, and is applied to access known structures in a rapid and inexpensive fashion. Finally, this work points to an interesting strategic departure for the use of Minisci chemistry at the earliest possible stage (native pyridine) rather than current dogma that almost exclusively employs Minisci chemistry as a late-stage functionalization technique.

Catalytic Conversion of Biomass to Furanic Derivatives with Deep Eutectic Solvents

Biomass is the only renewable organic carbon resource in nature, and the transformation of abundant biomass into various chemicals has received immense spotlight. As a novel generation of designer solvents, deep eutectic solvents (DESs) have been widely used in biorefinery due to their excellent properties including low cost, easy preparation, and biodegradability. Although there have been some reports summarizing the performance of DESs for the transformation of biomass into various chemicals, few Reviews illuminate the relationship between the functional structure of DESs and catalytic conversion of biomass. Hence, this Minireview comprehensively summarizes the effects of the types of functional groups in DESs on catalytic conversion of biomass into furanic derivatives, such as carboxylic acid-based hydrogen-bond donors (HBDs), carbohydrate-based HBDs, polyalcohol-based HBDs, amine/amide-based HBDs, spatial structure of HBDs, and various hydrogen-bond acceptors (HBAs). It also further summarizes the effects of adding different additives into the DESs on the synthesis of high value-added chemicals, including water, liquid inorganic acids, Lewis acids, heteropoly acids, and typical solid acids. Moreover, current challenges and prospects for the application of DESs in biomass conversion are provided.

Salts, solvates and hydrates of the multi-kinase inhibitor drug pazopanib with hydroxybenzoic acids

Eight cocrystal-salts of the multi-kinase drug pazopanib with hydroxybenzoic acids are sustained by the strong, ionic aminopyridinium⋯carboxylate heterosynthon of N–H⋯O hydrogen bonds between the carboxylic acid donor and amino-pyrimidine acceptor.

Optimizing Photoluminescence Quantum Yields in Uranyl Dicarboxylate Complexes: Further Investigations of 2,5‐, 2,6‐ and 3,5‐Pyridinedicarboxylates and 2,3‐Pyrazinedicarboxylate

The 2,5‐, 2,6‐, and 3,5‐pyridinedicarboxylic (2,5‐, 2,6‐ and 3,5‐pydcH2), and 2,3‐pyrazinedicarboxylic (2,3‐pyzdcH2) acids have been used to synthesize six uranyl ion complexes including various counterions under solvo‐hydrothermal conditions. While [NH4]2[UO2(2,6‐pydc)2]·3H2O (1) is a discrete, mononuclear species, [UO2(2,6‐pydc)2Cu(R,S‐Me6cyclam)] (2) crystallizes as a monoperiodic coordination polymer through axial bonding of copper(II) to carboxylate donors. [PPh3Me][UO2(OH)(2,5‐pydc)]·H2O (3) and [Ni(R,S‐Me6cyclam)][UO2(OH)(2,5‐pydc)]2·2H2O (4) contain di‐hydroxo‐bridged dinuclear uranyl subunits assembled into homometallic, monoperiodic polymers. [(UO2)2(3,5‐pydc)2(HCOO)2Ni(R,S‐Me6cyclam)] (5) crystallizes as a heterometallic diperiodic network with the V2O5 topology, and [PPh4][UO2(OH)(2,3‐pyzdc)] (6) is a diperiodic species with sql topology. All complexes have well‐resolved uranyl emission spectra in the solid state, and three of them have photoluminescence quantum yields among the highest reported for uranyl carboxylate complexes, 44 % for 1, 71 % for 3, and 36 % for 6.

Facile Method to Prepare pH-Sensitive PEI-Functionalized Carbon Nanotubes as Rationally Designed Vehicles for Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) Delivery

A new pH-sensitive system designed for drug-delivery purposes and based on functionalized multiwall magnetic carbon nanotubes (Mag-CNTs) was synthesized for the effective incorporation of non-steroidal anti-inflammatory drugs (NSAIDs), aiming at drug release in characteristic acidic conditions close to the actual conditions of inflamed tissues. Cationic hyperbranched polyethyleneimine (PEI) was immobilized on the surface of Mag-CNTs via electrostatic interactions between the positively charged protonated amines within the polymer and the carboxyl groups on the chemically oxidized Mag-CNT surface. The addition of the NSAID with a carboxylate donor, Naproxen (NAP), was achieved by indirect coupling through the amino groups of the intermediate linker PEI. FT-IR, Raman, and UV–vis spectroscopy were employed to fully characterize the synthesized nanocarrier and its functionalization procedure. The interaction of the designed nanocarrier with bovine serum albumin (BSA) was studied in vitro by fluorescence emission spectroscopy while its in vitro interaction with calf-thymus (CT) DNA was monitored by UV–vis spectroscopy and viscosity measurements and via competitive studies with ethidium bromide. The calculated binding constants were compared to those of free NAP revealing a higher binding affinity for BSA and CT DNA. Finally, drug-release studies were performed, revealing that the electrostatic linkage ensures an effective release of the drug in the acidic pH typical of inflamed cells, while maintaining the multiwall nanotubes (MWNTs)–drug conjugates stable at the typical bloodstream.