Data gaps in Chemistry

Representative open questions

Showing 30 of 91 — one per source paper, highest-quality first.

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

  The dominant ortho-site OH-addition pathway for second generation oxidation of 1st-ROOH and 1st-RONO2 is reported to be consistent with analogous systems (toluene, phenol); however, direct comparative kinetic measurements quantifying the regioselectivity differences between these aromatic precursors under identical conditions are absent.

• Cyclooligophosphanes and their coordination chemistry (2021) · doi

  The coordination of partially organyl-substituted polycyclophosphanes has been mentioned (reference 32), but comprehensive structural and spectroscopic characterization of mixed organyl-substituted cyclooligophosphane coordination complexes, particularly with respect to 31P NMR patterns and solid-state structures, requires further systematic investigation.

• Christmas chemistry A–Z (2014) · doi

  The whisky section identifies methanol, isobutanol, 3-methyl-1-butanol, and ethyl acetate as key flavor molecules in aged single-malt whisky, but does not quantify how storage duration in port wine casks affects the concentration of these volatile compounds or their sensory perception thresholds.

• Olympian colour chemistry (2012) · doi

  Side-reaction rate constants are reported as small for spirooxazines and naphthopyrans, but the paper provides no quantitative comparison of these constants across structural variants or under different light exposure intensities and wavelengths, making it difficult to predict fatigue accumulation timescales for specific dye designs in real-world lens applications.

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

  While the paper isolates and characterizes the α-anomer, the corresponding β-diastereomer is not synthesized, isolated, or structurally characterized, preventing direct crystallographic comparison of how anomeric configuration affects sugar ring conformation and packing in the solid state.

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

  The study documented that SrII preferentially formed hydrated species outside the cage rather than participating in metal exchange within the Au₆Cd₃ framework. Quantitative analysis of the hydration sphere structure, hydration energy values, and kinetic barriers for Sr²⁺ desolvation in this specific supramolecular environment was not provided.

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

  The paper evaluated six boron-pyrazolone complexes (MPAP-1 to MPAP-6) against five drug-likeness rule sets but did not investigate blood-brain barrier (BBB) permeability, plasma protein binding, or renal clearance prediction specific to the charged or lipophilic nature of these tetravalent boron coordination compounds.

• Chitosan and radiation chemistry (2010) · doi

  Crosslinked chitosan synthesized by gamma irradiation shows maximum Cr(VI) adsorption at pH 3 and column regeneration capability, but the paper provides no data on reusability cycle limits, adsorption capacity degradation after multiple regeneration cycles, or comparison of regeneration efficiency between chemical and radiation-based methods.

• Introduction to Surface Chemistry Essentials (2013) · doi

  The paper describes oil-water emulsion instability (coalescence within minutes for 1 mm diameter drops) but provides no systematic data on emulsifier molecular structure requirements, interfacial tension reduction thresholds, or coalescence kinetics across different oil types and water compositions. Controlled experiments varying surfactant architecture and oil-water interfacial properties are needed to establish design criteria for stable emulsions in pharmaceutical and cosmetic applications.

• Basic Organometallic Chemistry (2016) · doi

  The paper states that ferrocene and derivatives serve as curing accelerators for unsaturated polyester resins but does not specify which ferrocene derivatives were tested, what cure time reductions were achieved, or how ferrocene concentration affects resin mechanical properties.

• Chemistry of Carbon and Hydrogen (2019) · doi

  The paper notes that hydrogen storage via carbon materials (graphenes, carbon nanotubes, buckyballs, and metal-organic frameworks) is mentioned in the summary, but provides no quantitative data on storage capacity (wt% or volumetric density), desorption temperatures, cycle stability, or comparative performance metrics across these different carbon-based adsorbent materials.

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

  The X-ray crystallographic characterization (CCDC 1955054-1955057) provided structural data for the zinc complexes, but the binding affinity and structural parameters for octaethyl-7,17-dioxobacteriochlorin complexes with other divalent and trivalent transition metals remain unmapped.

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

  Tris(thiazolyl)phosphines have only been minimally studied in coordination chemistry; only one tris(thiadiazolyl)phosphine has been reported to date with no systematic characterization of its metal binding behavior, chelation patterns, or catalytic potential compared to the extensively documented tris(triazolyl) and tris(imidazolyl) analogues.

• Quinolines, a perpetual, multipurpose scaffold in medicinal chemistry (2021) · doi

  Quinoline-metal complexes with platinum, ruthenium, and rhodanine were reported as therapeutically active, but pharmacokinetic parameters (absorption, distribution, metabolism, excretion) and metabolic stability of these metal-quinoline complexes in hepatic microsomal assays have not been characterized.

• Resonance-enhanced multiphoton ionization time-of-flight mass spectrometry for the real-time analysis of a retronasal aroma compound from a cumin sandwich (2026) · doi

  The study measured aroma volatilization behavior for only three discrete bread amounts (1 g, 3 g, 7 g); a continuous dose-response investigation is needed to establish the quantitative relationship between food matrix composition (bread-to-saliva ratio) and the duration time (γ2 – γ1) of p-cymene release in REMPI-TOFMS retronasal aroma analysis.

• Chemistry and Pharmacy (2012) · doi

  The paper argues that chemistry's productive power—particularly in organic synthesis generating millions of novel compounds annually—is understudied by philosophers of chemistry, yet provides no framework for assessing how this synthetic capacity in pharmaceutical chemistry relates to actual drug discovery rates, market approval, or clinical efficacy. A quantitative analysis tracking synthesis rates of novel compounds against successful pharmaceutical candidates would illuminate this relationship.

• cAMPS derivatives. A minireview over synthetic medicinal chemistry (2019) · doi

  Limited literature information exists on 8-oxygeno cAMPS derivatives; while (Rp)- and (Sp)-8-OH-cAMPS stereoisomers are reported to have reduced membrane permeability compared to (Rp)-cAMPS due to hydroxyl polarity, systematic structure-activity relationship studies across different 8-oxygen substituents (alcohols, ethers, esters) and their respective membrane transport kinetics are absent.

• Multicomponent reactions in crop protection chemistry (2020) · doi

  Downy mildew disease control compounds have been discovered through multicomponent reactions, but comparative efficacy and selectivity data against resistant pathogen populations and alternative crop protection targets remain absent from the literature.

• Special issue: Plant synthetic biology (2020) · doi

  Chlorinated derivatives of benzene (chlorobenzene, dichlorobenzenes, trichlorobenzenes) were repeatedly detected in Moscow snow samples across multiple studies, yet the specific regional and seasonal sources of these halogenated compounds in the Moscow metropolitan area have not been systematically characterized or ranked by contribution magnitude.

• The coordination chemistry of aluminium in neurodegenerative disease (2012) · doi

  While computational research supports high affinity interactions between Al3+ and nucleic acid bases and monophosphate nucleotides, quantitative binding data for DNA–Al complexes exist only under acidic conditions. No quantitative data are available under near-physiological pH conditions where aluminium is consistently observed to co-precipitate with DNA, creating a critical gap between predicted and measurable aluminum-DNA coordination chemistry.

• Chemical and biological properties of anti-wrinkle peptide Argireline (2021) · doi

  The specific cream formulation ingredients that act as oxidants toward Argireline have not been identified. A systematic screening study is needed to determine which cosmetic excipients (preservatives, antioxidants, emulsifiers) promote or inhibit peptide oxidation in topical formulations.

• Self-Assembly of Complementary Components Using a Tripodal Bismuth Compound: Pnictogen Bonding or Coordination Chemistry? (2021) · doi

  The paper examines self-assembly in benzene-d6 solution via NMR but does not systematically investigate how solvent polarity or donor capability affects the pnictogen bonding vs. coordination chemistry equilibrium. Testing the 2·Py3 system in solvents ranging from non-polar (CCl4) to polar (DMSO) would establish whether solvent environment modulates the interaction mechanism.

• Bioactive compounds from the cultured lichenmycobiont of Nigrovothelium inspersotropicum (2026) · doi

  Compound 7 exhibited no inhibitory activity against HIV-1 reverse transcriptase at 200 μM concentration. The structural characterization and biological activity profile of compound 7 are not discussed; elucidation of compound 7's structure and assessment of its activity against other therapeutic targets (e.g., inflammatory mediators, oxidative stress markers) would improve understanding of structure-bioactivity relationships within this lichen metabolite library.

• Atmospheric oxidation chemistry of hexafluoroisobutylene initiated by OH radical: Kinetics and mechanism (2021) · doi

  The atmospheric lifetime calculation for (CF3)2C=CH2 was determined at 298 K only; temperature-dependent kinetic measurements across the full range of tropospheric conditions (200-320 K) are needed to accurately predict persistence of this persistent organic pollutant across different atmospheric layers and seasonal variations.

• A more ethical chemistry (2017) · doi

  The paper asserts that consumers lack knowledge about chemical risks in products (sunscreen nanoparticles, spray foam respiratory effects, antibacterial agents) but does not provide data on actual consumer knowledge, risk perception accuracy, or effectiveness of different disclosure mechanisms. Research comparing labeling formats, warning symbols, and notification systems is needed to identify optimal communication strategies for informed consent.

• Dynamic Chemistry of Anion Recognition (2011) · doi

  The paper demonstrates exceptional sulfate selectivity against selenate in crystalline frameworks with Li+ cations yielding pyrite topology, but competitive crystallization selectivity data comparing sulfate against carbonate and selenate in the same Li-based system are not provided. Systematic binding affinity measurements and selectivity ratios across different divalent oxoanions in identical frameworks are needed.

• Supramolecular polymer chemistry meets computational chemistry: theoretical simulations on advanced self-assembling chiral materials (2018) · doi

  While dimer F was identified as the most stable conformer for pyreneimidazoles, the computational framework has not explored whether chiral alkyl chains (present in derivative 7b) induce structural deviations from the achiral variant (7a) that could affect H-bond contact distances and the CH···π interaction geometry in larger aggregates.

• Progress in molecular uranium-nitride chemistry (2014) · doi

  The relative stability of uranium(V) versus uranium(VI) nitride linkages is demonstrated through differential photochemical reactivity and oxidation method effects (oxidation of 23 with I₂ yields 27, but analogous oxidation of 22 does not), yet quantitative thermodynamic or kinetic measurements comparing the stability thresholds across oxidation states are absent.

• Aqueous Chemistry (2012) · doi

  The dissolution and precipitation section establishes equilibrium relations using solubility product constants (Ksp) but acknowledges that precipitation rates are difficult to generalize. The paper does not identify which specific aqueous chemistry conditions (pH range, ionic strength, temperature, competing ligands) require kinetic rate constant determination for arsenic precipitation in natural groundwater systems.

• When Stereochemistry Raised Its Ugly Head in Coordination Chemistry—An Appreciation of Howard Flack (2020) · doi

  Many coordination compounds exhibiting spontaneous resolution in chiral Sohncke space groups are present in the Cambridge Structural Database but are not explicitly identified or discussed for their absolute configuration in their original publications. A comprehensive annotation effort is needed to systematically identify and characterize these overlooked cases of chirality in tris(chelate) metal complexes.