Carboxylic Function Research Articles

Polyfluorinated benzoic acids as promising reagents for organic synthesis and medicinal chemistry

Polyfluoroaromatic compounds occupy a special place in organic synthesis due to a wide range of their chemical transformations and unique biological properties. The introduction of the carboxyl function into polyfluoroarenes allows further diversification of the chemistry of these compounds. This review summarizes data on the chemical transformations of polyfluorobenzoic acids, including derivatives of polyfluorosalicylic acids. The reactions of esterification, amidation, reduction, decarboxylation, metal-catalyzed decarboxylative cross-coupling, C–H functionalization, reductive defluorination, nucleophilic aromatic substitution, heterocyclization and complex formation are considered. Reactivity features of polyfluorobenzoates in comparison to their non-fluorinated counterparts are highlighted. The potential for practical applications of polyfluorobenzoic acid derivatives, primarily as biologically active compounds, is presented. <br> Bibliography includes 300 references.

Co-regulating the pore structure and surface chemistry of sludge-based biochar for high–performance deodorization of gaseous dimethyl disulfide

A straightforward and eco-friendly preparation method for porous sludge biochar (SBA-3) was developed to deodorize gaseous dimethyl disulfide (DMDS) using ion exchange to adjust micropore structures coupled with carboxyl functionalization. Compared with the unmodified sludge biochar SBA-1 and SBA-2 treated with ion exchange, the pore size of SBA-3 decreased accompanied with increasing specific surface area and micropore volume. The Brunauer–Emmett–Teller (BET) specific surface area and micropore volume were 176.35 m2 g−1 and 0.0314 cm³ g−1, which were 2.02 and 1.71-fold larger than those of SBA-2, as well as 20.60 and 78.5-fold larger than those of SBA-1, respectively. Meanwhile, the amount of –COOH on the surface of SBA-3 increased from 0.425 to 1.123 mmol g−1, which was 2.64-fold larger than that of SBA-1. The adsorption behavior between DMDS and SBA-3 could be well described by the quasi-second-order kinetic model and Langmuir isotherm model. The maximum monolayer adsorption capacity was 35.12 mg g−1 at 303 K. Thermodynamic and DFT calculations indicated that the adsorption of DMDS on SBA-3 was exothermic with the deodorization mechanisms involving pore filling and chemisorption.

Comprehensive Qualitative and Quantitative Analysis of Flavonoids in Dandelion (Taraxacum officinale) Flowers and Food Products.

Taraxacum officinale, a cosmopolitan perennial, is widely used as an edible, fodder, honey, and medicinal plant. Interestingly, detailed LC-QTOF-MS profiling of the flower extract revealed the presence of several flavonoid signals, most likely lacking literature confirmation. Targeted isolation, including extraction based on DoE planning, led to the isolation of 11 flavonoids, three of which were new (16, 18, and 33). Their structures were determined by the NMR technique. Both biflavones (16 and 18) were structured by two luteolin molecules, linked by a C-C bond through IB (C-6') and IIA (C-6″ or C-8″) rings. Novel flavonolignan (33) was composed of tricin and an unusual carboxyl function containing a lignan moiety. The content of 28 flavonoids (glycosides, aglycones, biflavones, and flavonolignans) was determined by the LC-MS/MS method in raw flowers and dandelion syrups and tincture. Multivariate analyses showed the separation of spring and autumn flowers and a high diversity of food products and helped to identify metabolites correlated with the samples.

Investigating Cellulose Nanocrystal and Polyvinyl Alcohol Composite Film in Moisture Sensing Application

This study focused on utilizing cellulose nanocrystal (CNC)–polyvinyl alcohol (PVA) composite in optical sensor applications to detect high humidity conditions and determine water concentration in ethanol. We focused on the composite’s effectiveness in moisture absorption to demonstrate visual color change. We demonstrated that the different molecular weights of PVA significantly affect CNC’s chiral nematic structure and moisture absorption capability. PVA with molecular weight 88 k–97 k exhibited the disintegration of its chiral nematic structure at 30 wt%, whereas low molecular weight PVA (n~1750) showed no structural disintegration even at 100 wt% concentration when analyzed through UV-Vis spectroscopy. Further, the thermal crosslinking of the CNC-PVA composite showed no significant loss of moisture sensitivity for all molecular weights of the PVA. We observed that the addition of PVA to the sulfated CNC obtained from sulfuric acid hydrolysis did not facilitate moisture absorption significantly. A CNC-PVA sensor was developed which can detect high humidity with 2 h. of exposure time. 2,2,6,6-tetramethylpiperidin-1-piperidinyloxy oxidized CNC (TEMPO-CNC) having carboxylic functionality was also used to prepare the CNC-PVA composite films for comparing the effect of functional groups on moisture sensitivity. Finally, we demonstrated a facile method for utilizing the composite as an optical sensor to detect water concentration in ethanol efficiently; thus, it can be used in polar organic solvent dehydration applications.

Selective Profiling of Carboxylic Acid in Crude Oil by Halogen Labeling Combined with Liquid Chromatography and High-Resolution Mass Spectrometry.

Carboxylic acids are a small but essential compound class within petroleum chemistry, influencing crude oil behaviors in production and processing and causing environmental impacts. Detailed structural information is fundamental to understanding their influence on petroleum characteristics. However, characterizing acids in crude oil remains challenging due to matrix effects, structural diversity, and low abundance. In this work, we present a new methodology for profiling carboxylic acids by liquid-liquid extraction and selective derivatization using 4-bromo-N-methylbenzylamine (4-BNMA) followed by liquid chromatography and electrospray ionization Orbitrap mass spectrometry (LC-ESI-Orbitrap MS). The fragmentation of 4-BNMA derivatives produces a unique product ion pair, m/z 169/171, enabling the identification of chromatographic fractions containing carboxylic acids. The mass spectra of the corresponding fractions are extracted, and the acids are further computationally isolated based on the isotopic pattern. The method was optimized and validated using acid standards and systematic experimental designs, assuring robustness and sensitivity for nontarget screening purposes. This method detected up to 380 carboxylic acids in six Danish North Sea crude oils, with up to two carboxyl and other heteroatom functionalities (NSO). The results indicated that the most populated species are fatty acids (double bond equivalent (DBE) = 1) and small aromatic acids (DBE = 2-6). The predominance and diversities of compound classes in different samples are consistent with their corresponding bulk properties. Polyfunctional acids (Ox, NxOx, and SxOx) were observed due to exposure to oxidation and biodegradation. Also, the approach's applicability benefits high-resolution MS analysis by simplifying data processing for crude oil and potentially other high-organic and aqueous samples.

Structure, rheology and stability of walnut oleogels with different carboxylation degree of cellulose nanofiber

The effects of carboxylation degree (0.3–2.4 mmol/g) of cellulose nanofiber (CNF) on the microstructure and mechanical properties of edible walnut oleogels were comprehensively examined. The oleogels were well prepared by emulsion-templated approach for potential substitute of conventional saturated or trans-fats in food products. The results demonstrated that the oil-binding capacity (OBC) and textural strength of oleogels enhanced with the increase of CNF carboxyl content, while the structural strength (G' in rheological measurement) and the resistance to shear thinning was first decreased and then increased. It possibly reflected the competition on the dominant structuring mechanism by hydrogen bonding from cellulose hydroxyl groups and electrostatic interactions from –COONa function. With the combined mechanism, oleogel with low structural strength and relatively high OBC (CNF carboxyl content of 1.2 mmol/g, OBC >83 %, G′ ≈ 7 × 104 Pa and firmness of 0.30 N) and oleogel with enough structural rigidity and high OBC (CNF carboxyl content of 1.8 mmol/g, OBC >89 %, G′ of up to 1.7 × 105 Pa, and firmness of up to 0.66 N) were both fabricated. This reveals the feasibility of regulating oleogel structure and textual properties by using CNF as the unique oleogelator and simply changing its surface carboxyl function.

C-Terminal Decarboxylation of Proline-Derived Building Blocks for Protein-Binding Peptides.

Using a set of conformationally restricted Proline-derived Modules (ProMs), our group has recently succeeded in developing inhibitors for the enabled/vasodilator-stimulated phosphoprotein homology 1 (EVH1) domain, which is a key mediator of cell migration and plays an important role in tumor metastasis. While these (formally) pentapeptidic compounds show nanomolecular binding affinities towards EVH1, their drug-like properties and cell permeability need to be further optimized before they can be clinically tested as therapeutic agents against metastasis. In this study, we sought to improve these properties by removing the C-terminal carboxylic acid function of our peptoids, either by late-stage decarboxylation or by direct synthesis. For late-stage decarboxylation of ProM-like systems, a method for reductive halo decarboxylation was optimized and applied to several proline-derived substrates. In this way, a series of new decarboxy ProMs suitable as building blocks for decarboxy EVH1 inhibitors were obtained. In addition, we incorporated decarboxy-ProM-1 into the pentapeptide-like compound Ac[2ClF][ProM-2][Decarb-ProM-1], which showed similar affinity towards EVH1 as the methyl ester derivative (Ac[2Cl-F][ProM-2][ProM1]OMe). However, despite better calculated drug-like properties, this compound did not inhibit chemotaxis in a cellular assay.

Heteronuclear Complexes of Hg(II) and Zn(II) with Sodium Monensinate as a Ligand.

The commercial veterinary antibiotic sodium monensinate (MonNa) binds mercury(II) or zinc(II) cations as thiocyanate [Hg(MonNa)2(SCN)2] (1) or isothiocyanate [Zn(MonNa)2(NCS)2] (2) neutral coordination compounds. The structure and physicochemical properties of 1 and 2 were evaluated by the methods of single crystal and/or powder X-ray diffraction, infrared, nuclear magnetic resonance, X-ray photoelectron spectroscopies, and electrospray-mass spectrometry. The primary cores of the two complexes comprise HgS2O2 (1) and ZnN2O2 (2) coordination motifs, respectively, due to the ambidentate binding modes of the SCN-ligands. The directly bound oxygen atoms originate from the carboxylate function of the parent antibiotic. Sodium cations remain in the hydrophilic cavity of monensin and cannot be replaced by the competing divalent metal ions. Zinc(II) binding does not influence the monensin efficacy in the case of Bacillus cereus and Staphylococcus aureus whereas the antimicrobial assay reveals the potential of complex 2 as a therapeutic candidate for the treatment of infections caused by Bacillus subtilis, Kocuria rhizophila, and Staphylococcus saprophyticus.

Broken crystal symmetry of MWCNTs as the key factor in improvement of carboxyl functionalization

Carbon nanotubes functionalized with carboxyl groups (COOH-CNTs) find their application in energy storage, sensing, improving mechanical stability and biomedicine. So a facilitation of COOH-groups bonding to CNTs is one the modern scientific challenges. In this study untreated multi-walled CNT (MWCNTs), nitrogen-doped MWCNT (N-MWCNTs) and ion-beam irradiated N-MWCNTs (irr-N-MWCNTs) were synthesized using the CVD method. Characterizations were performed via HRTEM, Raman, XPS, and NEXAFS spectroscopy. Irr-N-MWCNTs demonstrated the largest amount of carbon crystallites, the presence of Stone-Wales defects as well as the regions of tensile-compressive, shear and torsional deformation. All these factors contributed to increase of carboxyl functionalization at the tube’s surface. On the base of experimental data, the atomic supercells of N-MWCNTs and irr-N-MWCNTs were built by the self-consistent-charge density-functional tight-binding method (SCC DFTB). Through SCC DFTB, we quantified atomic rearrangements, electronic structures, charge transfers, total energies, and the forces and energy barriers relevant to COOH bonding. The twisting of irr-N-MWCNTs supercells by 45 degrees decreased the barrier to the carboxyl formation in 2.5 times in comparison to undeformed nanotubes. Our findings reveal that nitrogen addition, ion-beam irradiation, and induced deformations create the necessary conditions for COOH functionalization by altering the physicochemical surface properties of MWCNTs.

Exploring the astrobiological potential of rock varnish from a mars analogue field site of Ladakh, India

Rock varnish, a dark-coloured natural feature rich in manganese (Mn), iron (Fe), and clay minerals that forms on rock surfaces and subsurface rock fractures in extremely dry and cold environments, is believed to provide nutritional support to microbiota. Because varnish supports an extensive microbial community, this rock coating is considered a substrate for potential microbial life to thrive in extreme environments on Earth. Although research in the past decades have advanced understanding of the varnish microbiome, little is known about this microbial community in settings that are high altitude (lower oxygen), dry, and cold. We present here new morphological, chemical, and rock magnetic results of rock varnish from this environmental setting, the Ladakh, a potential analogue site for life in extreme environments. Our results include the presence of putative magnetofossils-in the form of nanochains present in the rock varnish layer. Further, the higher concentrations of oxidised Mn4+ and carboxylic acid functionality on the varnish surface revealed organic signatures. These collective results point towards the enriched concentration of magnetic minerals on the varnish layer that are possibly sourced through biotic forms. Consequently, the rock varnish can serve as an archive of ancient environmental records, as well as a potential geomaterial for astrobiological studies from the Martian analogue field location of Ladakh, which needs to be explored further for extensive biogeochemical studies.

Photoluminescent sensing of HepG2 cells with a metal-organic framework / molybdenum disulphide nanosheets composite probe

The photoluminescence-based detection of circulating tumor cells (CTCs) can offer the development of rapid, simple, and sensitive techniques for the screening of cancer at early stages as well the monitoring of therapy progression. The present work reports the application of a photoluminescent composite of Terbium based metal–organic framework (Tb-BTC MOF) with L-cysteine conjugated molybdenum disulphide (MoS2) nanosheets for the highly sensitive immunosensing of HepG2 cells. The formation of the above composite facilitates the achievement of a highly fluorescent, large surface area material with abundant carboxyl functionality. This novel composite has been immobilized with the anti-EpCAM antibodies to form the desired immunosensor for HepG2 cells. After spectroscopic and morphological characterizations, the antibody immobilized Tb-BTC/MoS2 bioprobe (Ab/Tb-BTC/MoS2) has been investigated for the sensing of HepG2 cells (10–1000 cells). Based on the PL quenching mechanism, the above bioprobe has delivered a broad range analysis with a low limit of detection (8 cells). The Ab/Tb-BTC/MoS2 bioprobe is also found selective toward other possible interferants, such as HEK cells, bovine serum albumin, immunoglobin G, and glucose.

Competing electrophilic substitution and oxidative polymerization of arylamines with selenium dioxide.

This article describes the detailed analysis of the reaction between arylamines, such as aniline, o-anisidine, and methyl anthranilate, with selenium dioxide in acetonitrile. A systematic analysis of the reaction products with the help of 77Se NMR and single-crystal X-ray crystallography revealed that the reaction progress follows three major reaction pathways, electrophilic selenation, oxidative polymerization, and solvent oxidation. For aniline and o-anisidine, predominant oxidative polymerization occurred, leading to the formation of the respective polyaniline polymers as major products. For methyl anthranilate, the oxidative polymerization was suppressed due to the delocalization of amine lone pair electrons over the adjacent carboxylate function, which prompted the selenation pathway, leading to the formation of two of the isomeric diorganyl selenides of methyl anthranilate. The diaryl selenides were structurally characterized using single-crystal X-ray diffraction. Density functional theory calculations suggest that the highest occupied molecular orbital of methyl anthranilate was deeply buried, which suppressed the oxidative polymerization pathway. Due to solvent oxidation, oxamide formation was also noticed to a considerable extent. This study provides that utmost care must be exercised while using SeO2 as an electrophile source in aromatic electrophilic substitution reactions.

Insights into Plastic Degradation Processes in Marine Environment by X-ray Photoelectron Spectroscopy Study.

The present study employs X-ray photoelectron spectroscopy (XPS) to analyze plastic samples subjected to degradation processes with the aim to gain insight on the relevant chemical processes and disclose fragmentation mechanisms. Two model plastics, namely polystyrene (PS) and polyethylene (PE), are selected and analyzed before and after artificial UV radiation-triggered weathering, under simulated environmental hydrodynamic conditions, in fresh and marine water for different time intervals. The object of the study is to identify and quantify chemical groups possibly evidencing the occurrence of hydrolysis and oxidation reactions, which are the basis of degradation processes in the environment, determining macroplastic fragmentation. Artificially weathered plastic samples are analyzed also by Raman and FT-IR spectroscopy. Changes in surface chemistry with weathering are revealed by XPS, involving the increase in chemical moieties (hydroxyl, carbonyl, and carboxyl functionalities) which can be correlated with the degradation processes responsible for macroplastic fragmentation. On the other hand, the absence of significant modifications upon plastics weathering evidenced by Raman and FT-IR spectroscopy confirms the importance of investigating plastics surface, which represents the very first part of the materials exposed to degradation agents, thus revealing the power of XPS studies for this purpose. The XPS data on experimentally weathered particles are compared with ones obtained on microplastics collected from real marine environment for investigating the occurring degradation processes.

Broadening the coating applications of sustainable materials by reinforcing epoxidized corn oil with single-walled carbon nanotubes

In the global context of environmental awareness, the present research proposes a sustainable alternative to the widely used petroleum-based epoxy coatings. Epoxidized corn oil (ECO) was tested as potential matrix for advanced nanocomposite coating materials reinforced with 0.25 to 1 wt.% single-walled carbon nanotubes (SW) with carboxyl and amide functionalities. The elemental composition of the epoxy networks was monitored by XPS, showing the increase of O/C ratio to 0.387 when carboxyl-functionalized SW are added. To achieve sustainable composite materials, citric acid was used as curing agent, as a substitute for conventional counterparts. The influence of both surface functional groups and concentration of SW was evaluated through structural and thermo-mechanical analysis. The progressive increase of the DSC enthalpy for SW formulated systems indicates a possible pattern for specific interactions within the bio-based epoxy translated by adjusted activation energy. For 1% neat SW addition, the Ea values decreased to 46 kJ/mol in comparison with 53 kJ/mol calculated for neat epoxy. Furthermore, the -COOH groups from SW nanostructures exerted a strong influence over the mechanical performance of bio-epoxy networks, improving the crosslinking density with ~ 60% and twofold the storage modulus value. Accordingly, by gradual addition of SW-COOH filler within the ECO-based formulations, a very consistent behaviour in seawater was noted, with a 28% decreased value for the absorption degree.Graphical

Exploring different classification-dependent QSAR modelling strategies for HDAC3 inhibitors in search of meaningful structural contributors.

Histone deacetylase 3 (HDAC3), a Zn2+-dependent class I HDACs, contributes to numerous disorders such as neurodegenerative disorders, diabetes, cardiovascular disease, kidney disease and several types of cancers. Therefore, the development of novel and selective HDAC3 inhibitors might be promising to combat such diseases. Here, different classification-based molecular modelling studies such as Bayesian classification, recursive partitioning (RP), SARpy and linear discriminant analysis (LDA) were conducted on a set of HDAC3 inhibitors to pinpoint essential structural requirements contributing to HDAC3 inhibition followed by molecular docking study and molecular dynamics (MD) simulation analyses. The current study revealed the importance of hydroxamate function for Zn2+ chelation as well as hydrogen bonding interaction with Tyr298 residue. The importance of hydroxamate function for higher HDAC3 inhibition was noticed in the case of Bayesian classification, recursive partitioning and SARpy models. Also, the importance of substituted thiazole ring was revealed, whereas the presence of linear alkyl groups with carboxylic acid function, any type of ester function, benzodiazepine moiety and methoxy group in the molecular structure can be detrimental to HDAC3 inhibition. Therefore, this study can aid in the design and discovery of effective novel HDAC3 inhibitors in the future.

Photoluminescent Carbon Quantum Dots from Dichrostachys glomerata Pods with Antioxidant and Cu2+ Chelating Properties

AbstractThis work presents the facile and single‐step hydrothermal synthesis of carbon quantum dots (CQDs) using the Dichrostachys glomerata extract as raw material. CQDs with the highest photoluminescence (PL) were obtained after heating the extract in 4 M NaOH at 200 °C for 7 h. The obtained CQDs exhibit an average size of ca. 4.7 nm, a green‐yellow PL emission independent on the excitation wavelength with contributions located at 478 and 562 nm, a monoexponential decay of their PL lifetime and a PL quantum yield of 18 %. These results indicate that the surface functionalization of sp2 clusters in CQDs is uniform. The antioxidant properties of CQDs were also investigated. CQDs can effectively reduce free radicals like superoxide or oxidants like KMnO4. Moreover, CQDs show a high Cu2+ chelating activity, which is attributed to the abundant carboxylate functions on their surface and may therefore be of high interest in therapeutic applications related to Cu2+ ions overload.

Effect of Amine, Carboxyl, or Thiol Functionalization of Mesoporous Silica Particles on Their Efficiency as a Quercetin Delivery System in Simulated Gastrointestinal Conditions.

Quercetin (Q) dietary supplements exhibit poor oral bioavailability because of degradation throughout gastrointestinal digestion (GD), which may be overcome using mesoporous silica particles (MSPs) as an oral delivery system (ODS). This study aimed to elucidate the effect of the functionalization of MSPs with amine-(A-MSP), carboxyl-(C-MSP), or thiol-(T-MSP) groups on their efficiency as a quercetin ODS (QODS). The type and degree of functionalization (DF) were used as factors in an experimental design. The Q-loaded F-MSP (F-MSP/Q) was characterized by gas physisorption analysis, loading capacity (LC), and dynamic light scattering and kinetics of Q release at gastric and intestinal pHs. Antioxidant capacity and Q concentration of media containing F-MSP/Q were evaluated after simulated GD. A-MSP showed the highest LC (19.79 ± 2.42%). C-MSP showed the lowest particle size at pH 1.5 or 7.4 (≈200 nm). T-MSP exhibited the maximum Q release at pH 7.4 (11.43%). High DF of A-MSP increased Q retention, regardless of pH. A-MSP preserved antioxidant capacity of Q-released gastric media (58.95 ± 3.34%). Nonetheless, MSP and F-MSP did not protect antioxidant properties of Q released in intestinal conditions. C-MSP and T-MSP showed essential features for cellular uptake and Q release within cells that need to be assessed.

Synthesis, Spectral Characterization, and Structural Modelling of Di- and Trinuclear Iron(III) Monensinates with Different Bridging Patterns

In the present study, we report the solid-state isolation and structural characterization of novel iron(III) complexes of the veterinary antibiotic monensin. Monensic acid (MonH × H2O) forms a dinuclear complex of composition with FeCl3 [FeCl(Mon)2]2 (1), while its interaction with FeSO4 leads to the isolation of a triangular oxo-ferric coordination species [Fe3O(Mon × H2O)6(H2O)2(OH)] (2). During the procedure resulting in 2, oxidation of the Fe(II) ions by atmospheric oxygen was observed. In the presence of organic bases, both complexation reactions proceeded to successfully deprotonate the carboxylic function of the ligand. Iron(III) complexes 1 and 2 were characterized by IR, EPR, NMR, and Mössbauer spectroscopies as well as with thermal (TG-DTA/MS) and elemental analyses. In addition, the structures of the two coordination compounds were modelled and selected calculated parameters were compared with the experimental results. The biological assay revealed the enhanced antibacterial potential of the newly obtained complexes against the Gram-positive aerobic microorganisms Bacillus cereus and Bacillus subtilis.

Clarifying the role of carboxyl functionality in squaraines towards aggregation and self-assembly through photophysical characterization and BSA interactions

The demand for near-infrared (NIR) probes with robust and stable fluorescence signals has surged, driven by their applications in optical sensing and bioimaging. Squraine dyes as NIR fluorescent probes have gained significant traction. However, understanding their behavior in aqueous media is important for their successful application. Herein we report the synthesis and photophysical characterization of carboxy-functionalized unsymmetrical squaraine dyes capable of light absorption and emission in the near-infrared (NIR) wavelength region. Structural variations in alkyl chain length, and spacer chain length between the primary chromophore and –COOH group were systematically introduced to investigate their impact on self-assembly in aqueous media leading to dye aggregation and their differential interactions with Bovine Serum Albumin (BSA) as a model protein. In phosphate buffer (PB) the absorption intensity decreased drastically along with pronounced shoulders due to dye aggregation leading to complete fluorescence quenching. However, in the presence of BSA, the intensity of shoulder bands reduced coupled with a sharp increase in the absorption associated with monomeric dye with the increasing concentration of BSA, indicating the prevention of dye aggregation owing to dye-BSA interactions. The prevention of dye aggregation due to dye-BSA interaction also led to a tremendous increase in the fluorescence intensities as a function of the increasing BSA concentrations. Site-selective study off BSA showed that these dyes bind preferably at Site-II using hydrophilic interactions. Thus, these dyes show great potential as FRET or fluorescent on/off probes for biosensing, non-covalent labeling of proteins, and fluorescent probes for bioimaging.

Zn(II) and Cd(II) complexes with 3-furoic acid. Exploring the role of C[sbnd]H···O interactions

Hydrogen bond interactions implying CH groups and O atoms either from carboxylate, carbonyl, or ether functionalities have been demonstrated to play a pivotal role in the packing of crystal structures. To analyze and compare their significance in metal carboxylate complexes with pyridine derivatives (dPy), we have synthesized four Zn(II) and Cd(II) compounds containing 3-furoic acid (3-FA) and two different pyridine ligands (isonicotinamide, isn; and 4-acetylpyridine, 4-acpy) affording two isostructural dimeric complexes [Zn(μ-3-FA)(3-FA)(isn)2]2 (1) and [Cd(μ-3-FA)(3-FA)(isn)2]2 (2), one dimeric paddle-wheel [Zn(μ-3-FA)2(4-acpy)]2 (3), and one monomer [Cd(3-FA)2(4-acpy)2(OH2)] (4). Their crystal structures have been elucidated and studied in detail, showing variable coordination modes of the 3-FA ligand and different coordination numbers. The CH···O interactions analysis of the four complexes in combination with their previously reported analogs with 2-furoic (2-FA) and piperonylic (HPip) acids, highlights the importance of such associations in the final crystal arrangement benefitting from cooperative effects. Finally, the photophysical properties in MeOH solution of 1–4 have been analyzed and their quantum yields calculated and compared.