Methodology gaps in Chemistry

Representative open questions

Showing 30 of 254 — one per source paper, highest-quality first.

• Bi-Polar Bioenergetic Intervention via a Pathology Self-Adaptive Single-Atom Nanocatalyst for Diabetic Tumor Postoperative Management (2026) · doi

  The paper demonstrates that PtSNC exhibits NOX-/OXD-/POD-like multi-catalysis in tumors, but the relative contribution of each catalytic activity to tumor cell death versus wound healing acceleration remains quantitatively unresolved. Differential inhibition studies targeting individual catalytic pathways are absent.

• Ultrasound-assisted adsorption of congo red dye using green synthesized silver nanoparticles coated with chitosan (2026) · doi

  Although the study uses green synthesis of silver nanoparticles from plant materials, it does not compare the adsorption performance of Chi-AgNPs synthesized using different plant precursors or evaluate how variations in the green synthesis protocol (extraction method, reaction time, temperature) influence the final adsorbent's dye removal capacity.

• Real-time P$$_2$$O$$_5$$ quantification in industrial phosphoric acid using laser-induced breakdown spectroscopy: a paradigm shift in process analytical chemistry (2026) · doi

  A small subset of samples exhibited larger residuals (approximately ±3-4% P2O5) attributed to genuine measurement challenges such as surface inhomogeneity, but the specific mechanisms by which surface inhomogeneity in wet phosphoric acid samples affects LIBS signal intensity and whether preprocessing methods beyond SNV and Savitzky-Golay smoothing can mitigate these effects remain unexplored.

• Mechanistic investigations of the formation of multifunctional products from the multi-generation ●OH oxidation of styrene (2026) · doi

  The fractional yields for second and third generation closed-shell products vary significantly (e.g., S26: 4.8%, S47: 26.3%, S62: 0.03%); systematic sensitivity analysis examining how experimental conditions (temperature, pressure, NOx concentration, humidity) affect these yield distributions has not been performed.

• High-Entropy Catalysts for Biomass-Derived Chemicals Valorization: Mechanisms, Applications, and Opportunities (2026) · doi

  In situ characterization of dynamic structure reconstruction phenomena in high-entropy catalysts during electrochemical oxidation of HMF and glycerol is limited. The paper identifies that oxyhydroxides formed during in situ reconstruction act as active sites, but mechanistic insights into how HEC structural evolution generates these active interfaces for biomass valorization require expanded use of operando spectroscopic techniques.

• Green Dispersive Liquid–Liquid Microextraction Using an Octanol-Menthol-Based Deep Eutectic Solvent for Sensitive UV–Vis Determination of Rhodamine B in Food and Water Samples (2026) · doi

  The DLLME-OCT-MEN-DES method demonstrated a relatively lower precision (RSD 7.3%) and enrichment factor (PF 10) compared to specialized detection techniques like DES-VALLME with luminescence and UA-HDES-ME; optimization strategies to improve these figures of merit without sacrificing the extraction time advantage should be explored.

• Photochemistry and photophysics of transition metal complexes: Quantum chemistry (2015) · doi

  The accuracy limitation of TD-DFT in describing both MC (metal-centered) and MLCT states simultaneously in organometallic complexes like Cr(CO)6 with better than 0.15 eV precision remains unresolved; comparison of TD-DFT with CASSCF/MS-CASPT2 and EOM-CCSD methods for transition metal dppz complexes across the absorption spectrum (360-800 nm) needs systematic benchmarking.

• The role of the bis-trimethylsilylamido ligand, [N{SiMe3}2]−, in main group chemistry. Part 1: Structural chemistry of the s-block elements (2015) · doi

  The polymeric chain formation in Na/Mn complex 256 through Na···Me contacts has been structurally characterized, but the solution-state behavior and equilibrium dynamics of this and related group 1/transition metal μ-N{SiMe3}2 complexes remain uninvestigated.

• Functional nanocomposites for energy storage: chemistry and new horizons (2020) · doi

  Replacing carbon with group 14 elements in polymer chains to tailor ionic polarization shows theoretical promise but presents significant synthesis challenges; the specific synthetic routes, reaction conditions, and scalability barriers for producing such modified polymers for nanocomposite capacitors remain unaddressed.

• Cyclooligophosphanes and their coordination chemistry (2021) · doi

  Synthetic routes to cyclooligophosphanes using P1, P2, and P4 building blocks exist (reference 49), but the scope and limitations of these approaches for preparing mixed-ring-size phosphorus systems (e.g., incorporating both tetraphosphane and hexaphosphane units in a single molecule) have not been explored.

• A review: recent progress of piezoelectric effect coupled photocatalytic reaction: diverse mechanisms, system/structure design, characterization and application (2026) · doi

  The in situ ultraviolet testing method for characterizing piezoelectric field modulation of band structure has been developed, but integration with other advanced characterization techniques such as Electron Paramagnetic Resonance and X-ray Photoelectron Spectroscopy coupled with external piezoelectric excitation devices remains unexplored.

• Christmas chemistry A–Z (2014) · doi

  The vanilla section notes a 100-fold discrepancy between natural vanilla extraction (100t/year) and global demand (20,000t/year), with most being chemically synthesized, but does not investigate the specific chemical synthesis pathways used commercially or compare the sensory/chemical profile differences between naturally extracted and synthetically produced vanillin at equivalent concentrations.

• Olympian colour chemistry (2012) · doi

  Multi-dye formulations for achieving neutral grey and brown lens shades require balancing up to six different photochromic dyes with complementary absorption spectra and kinetics. The paper lacks systematic guidelines for predicting which combinations of dihetarylethene, spirooxazine, and naphthopyran structural modifications (electron donor positioning, halogen substitution, alkoxy/amino groups) will optimize neutral colour without fatigue or kinetic mismatches.

• Biosensors: Enzyme Immobilization Chemistry (2018) · doi

  The affinity-based immobilization using concanavalin A or boronic groups is described as advantageous for controlling enzyme active site orientation, yet the paper provides no comparative data on active site orientation efficiency between glycan-mediated immobilization and other methods (covalent bonding, entrapment, polyelectrolyte multilayers) in actual biosensor applications.

• WITHDRAWN: Combinatorial Chemistry Online Volume 15, Issue 11, November 2013 (2013) · doi

  The iterative ligation approach for polypeptide synthesis using bis(2-sulfanylethyl)amido (SEA) peptide segments reported by Raibaut et al. has demonstrated efficiency for large polypeptides, but systematic optimization of coupling efficiency, segment length constraints, and compatibility with post-translational modifications in combinatorial contexts is absent.

• Methyl 2-deoxy-3,5-di-O-p-toluoyl-α-d-ribofuranoside: isolation, crystal structure and conformation (2026) · doi

  The crystal structure and conformational analysis of methyl 2-deoxy-3,5-di-O-p-toluoyl-α-D-ribofuranoside has been characterized, but comparative conformational studies with structurally similar 2-deoxy ribofuranose derivatives bearing different acyl protecting groups (beyond p-toluoyl and p-nitrobenzoyl) are lacking, limiting understanding of how protecting group substitution patterns influence sugar ring pseudorotation.

• Transmetallation Reaction of Alkali and Alkaline-earth Metal Ions in Supramolecular Complex of [{Au6Cd3(tdme)2(D-pen)6}Cd4Na4](NO3)12 (2026) · doi

  While the authors demonstrated that increasing metal-ion solution concentration from 1 M to 3 M did not promote exchange at the CdII center, no systematic study explored the effect of chelating agents, counterion identity, or pH on transmetallation selectivity at the metal-linker versus metal-center sites within the metallosupramolecular framework.

• Synthesis of Tetravalent Boron Complexes with Pyrazolone-Based Ligand and their Drug-Likeness (2026) · doi

  The synthesis and characterization of tetravalent boron complexes with 2-isopropoxy-1,3,2-benzodioxaborole and 5-methyl-2-phenyl-4-(2-phenylhydrazinylidene)-2,4-dihydro-3H-pyrazol-3-one was reported, but metabolic stability studies using liver microsomes or recombinant cytochrome P450 enzymes were not conducted to assess phase I/II biotransformation pathways of these specific boron-pyrazolone coordination compounds.

• Physical Organic Chemistry (POC) Makes Chemistry a Science: A Personal Reflection on POC (2016) · doi

  The integration of artificial intelligence and Big Data approaches with traditional physical organic chemistry methodology is proposed but not detailed. Clear protocols are required for how chemists should use machine-discovered correlations to reveal the 'why' in organic chemistry and guide hypothesis-driven experimental work.

• Chitosan and radiation chemistry (2010) · doi

  The paper suggests biotechnological processes and hybrid processes for chitosan production and degradation but does not specify which biotechnological organisms or hybrid radiation-chemical combinations should be investigated, their expected advantages over current radiation-only methods, or benchmarks for process efficiency.

• Introduction to Surface Chemistry Essentials (2013) · doi

  The paper identifies that no direct measurement procedure currently exists to characterize self-assembly monolayer (SAM) structures, limiting empirical verification of molecular arrangement at interfaces. Developing experimental techniques to directly measure SAM composition and orientation on solid substrates would advance understanding of interfacial organization beyond indirect surface tension measurements.

• Subject Index (2011) · doi

  Surfactant-based analyte separation using liquid-coacervate extraction and microemulsion-based separations with aphrons (pages 102-107, 105t) are presented as alternatives to conventional extraction, but the paper does not specify the green chemistry assessment (energy consumption, waste generation, toxicological profile) of these methods or comparison of operator exposure with traditional solvent extraction.

• Basic Organometallic Chemistry (2016) · doi

  The microwave synthesis procedure for Zeise's salt specifies heating at 130°C for 15 minutes with 50 psi ethylene loading, but the paper does not investigate how variations in temperature (below and above 130°C), ethylene pressure (below and above 50 psi), or solvent ratio affect product yield, purity, or reaction time.

• Initial organotin chemistry (2014) · doi

  Alternative synthetic routes to organotin compounds using silver salts (Ag2SO4, etc.) with trialkyltin iodides are described in Table 2, but the mechanism of iodide displacement and the kinetics of these halide-metathesis reactions have not been characterized.

• Using quantum chemistry to estimate chemical shifts in biomolecules (2020) · doi

  Machine learning approaches for predicting chemical shifts in molecular solids [14] have not been systematically combined with explicit solvation models in quantum chemical fragment methods for biomolecules under varying pH and ionic strength conditions.

• Chemistry of Carbon and Hydrogen (2019) · doi

  The reducing action of carbon (Section 26.12) presents four reduction reactions with metallic oxides, steam, sulphates, and acids, but does not characterize the reaction kinetics, temperature dependencies, catalyst requirements, or competitive pathways when multiple substrates are present in industrial metallurgical operations.

• Bis (N-Heterocyclic Carbene) Palladium Complex Immobilized Onto Fe3o4@Sio2 as a Catalyst for Sonogashira (Amine/Copper Free) and Hiyama Coupling of Arbr/Cl in Green Media (2026) · doi

  The catalyst recyclability studies demonstrate efficient reuse up to 6 cycles, but a pronounced efficiency drop occurs at the seventh cycle. The specific mechanism of catalyst deactivation—whether caused by Pd leaching, support degradation, or NHC ligand decomposition—requires investigation to enable extended operational lifetime of the Fe3O4@SiO2-supported Pd-NHC heterogeneous catalyst.

• Coordination chemistry of poly(thioether)borate ligands (2010) · doi

  The heretofore lack of thioether sulfur oxidation in [PhTtR] ligands is attributed to kinetically controlled ligand/solvent C–H activation as the major decomposition pathway, but this decomposition mechanism and its relative rates compared to donor atom oxidation have not been directly characterized spectroscopically or kinetically.

• Evaluation of Octaethyl-7,17-dioxobacteriochlorin as a Ligand for Transition Metals (2020) · doi

  The metal insertion kinetics were monitored only for zinc acetate complexation with octaethyl-7,17-dioxobacteriochlorin under reflux conditions in DMF. The reactivity of other transition metals (copper, nickel, cobalt, iron) with this dioxobacteriochlorin ligand under identical or varied conditions (temperature, solvent, pH) has not been systematically evaluated.

• Coordination chemistry of tris(azolyl)phosphines (2018) · doi

  The triazolylation reaction using OP(1,2,4Tz)3 has been conducted in three different solvent systems (acetonitrile, dichloromethane, and pyridine) with varying base conditions and product yields (up to 60% in pyridine), but no systematic solvent-base screening or mechanistic investigation has been reported to optimize reaction conditions or understand why pyridine occasionally produces only pyridinium salts as side products.