Data gaps in Chemistry

Representative open questions

Showing 30 of 107 — 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 volatility predictions for third-generation closed-shell products (S47, S51, S58, S62) rely on SIMPOL.1 estimation methods; direct experimental measurements of saturation vapor pressure and condensation behavior of these highly oxygenated and nitrogenated compounds under atmospheric conditions are needed to validate particle formation potential.

• 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 bridging bis-trimethylsilylamido ligand between group 1 and group 14 elements (Ge, Sn) has only one crystallographically characterized example despite extensive work with both MN{SiMe3}2 reagents and homoleptic group 14 compounds. Systematic synthetic routes and structural characterization of additional group 1/14 complexes containing the μ-N{SiMe3}2 bridge are needed to establish general coordination patterns.

• Cyclooligophosphanes and their coordination chemistry (2021) · doi

  The coordination chemistry of cyclooligophosphanes with transition metals has been documented for specific ring sizes (tetraphosphanes, hexaphosphanes), but systematic coordination studies with larger ring systems such as octadecaphosphanes (P18) and icosaphosphanes (P20) remain unexplored, limiting understanding of how ring size affects metal binding modes and complex stability.

• 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.

• Basic Organometallic Chemistry (2016) · doi

  While ferrocene's application in promoting smoke-free fuel combustion and preventing engine knocking is mentioned, the paper provides no quantitative data on combustion efficiency improvements, emission reduction percentages, or optimal ferrocene concentrations for these fuel applications.

• 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

  Large variability in start time (standard deviation 2.8 s) and especially end time (standard deviation 8.6 s) for retronasal aroma release was attributed to individual differences across four panelists, but the study did not systematically characterize which physiological or anatomical factors (saliva secretion rate, oral cavity geometry, breathing pattern) drive this inter-individual variability in REMPI-TOFMS measurements.

• 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

  While hexamethylphosphoramide (HMPA) was identified in Moscow snow samples with multiple known applications (polymer solvent, polymerization catalyst, UV stabilizer, flame retardant, anti-freezing additive), the specific emission pathways and dominant sources contributing to its environmental presence remain unclear and require source-receptor modeling studies specific to HMPA.

• 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.

• Chemistry of Fungal Products (2011) · doi

  Multiple artemisinin derivatives (compounds 53, 54, 55-59) are screened against only two P. falciparum drug-resistant clones (W-2 and D-6), but the paper does not evaluate their efficacy against other chloroquine or mefloquine resistant Plasmodium species (P. vivax, P. malaria, P. ovale) or assess cross-resistance potential.

• Systematics and surprises in lanthanide coordination chemistry (2017) · doi

  The coordination number transition in the lanthanide series occurs at different points depending on ligand type (e.g., coordination number changes mid-series for Ph3PO complexes with thiocyanate, but at different positions for terpy with nitrate). Systematic structural comparison across the complete lanthanide series (La-Lu, including Pm) for the same ligand-counterion combination is needed to map where discontinuities occur and why.

• 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.

• Flow Chemistry in Drug Discovery: Challenges and Opportunities (2021) · doi

  The paper discusses solubility limitations in flow chemistry compared to parallel batch approaches (which can perform diverse chemistries regardless of solvent mixture solubility), but provides no concrete data on the specific solubility thresholds that prevent flow chemistry applicability or systematic guidelines for predicting which reaction classes will face solubility constraints in continuous flow reactors.

• A more ethical chemistry (2017) · doi

  The paper identifies 287 chemicals in umbilical cord blood but does not specify which of these chemicals lack adequate toxicological characterization or have incomplete exposure pathway data. A systematic inventory is needed that categorizes these 287 chemicals by data gaps in developmental neurotoxicity, teratogenicity, and carcinogenicity testing to identify priority chemicals for targeted research.

• The inorganic chemistry of coals (2013) · doi

  The paper acknowledges that Table 18.3 does not represent a complete catalog of all phase transitions and reactions occurring among inorganic coal components. Systematic investigation is needed to identify and characterize additional mineral transformations beyond those listed, particularly for less common coal minerals and their interactions in oxidizing atmospheres across the full temperature range from 300-1500°C.

• Overview of some quantum effects in chemistry (2011) · doi

  The theoretical model showing that non-Gaussian distributions of energy level fluctuations preserve selective population transfer efficiency with minimal loss (Fig. 8) was demonstrated only for HCl in Ar at T = 60K and 120K. Extension to polyatomic molecules in different solvent environments and across broader temperature ranges is needed to establish generalizability of this finding.

• 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.