{"title":"Hierarchical Molecular Structure–Based Method to Estimate the Normal Boiling Point of Aliphatic Oxygen-Containing Organic Compounds","authors":"Jincan Long, Chao-Tun Cao, Chenzhong Cao","doi":"10.1002/poc.70020","DOIUrl":"https://doi.org/10.1002/poc.70020","url":null,"abstract":"<div>\u0000 \u0000 <p>In this work, a hierarchical molecular structure method (HMSM) was proposed to extract molecular descriptors. In this method, the molecular structure is divided into three hierarchies: the first hierarchy involves the contributions of the number of vertices (vertex number <i>m</i> and the sum of vertex number effect, <i>S</i><sub>VNE</sub>); the second hierarchy involves the contributions of the vertex skeleton (odd-even index, OEI, and intramolecular polarization effect index, IMPEI); and the third hierarchy involves the contributions of the functional group (polarization effect index, PEI, and group influencing factor, <i>G</i><sub>N</sub>). Using these six molecular descriptors, the normal boiling points (NBP) of aliphatic oxygen-containing organic compounds (AOCOCs), including alcohols, ethers, aldehydes, ketones, carboxylic acids, and esters, can be quantitatively correlated well. The results show that the average absolute percentage error (APPE) between the experimental and calculated NBP values for each series of AOCOCs is less than 1%. Based on the obtained QSPR models, the NBPs of some AOCOCs that have not been experimentally measured were predicted, including 14 alcohols, 25 ethers, 106 aldehydes, 72 ketones, 103 carboxylic acids, and 57 esters. Additionally, a QSPR model for all 518 AOCOCs was also derived, yielding an APPE value of only 1.35%, indicating that the HMSM-based QSPR model performs exceptionally well in the field of QSPR modeling. The specific contributions of functional groups to NBP were discussed and their order is as follows: <span></span>COOH > <span></span>OH > <span></span>COO<span></span> > <span></span>C(O)<span></span> > <span></span>CHO > <span></span>O<span></span>.</p>\u0000 </div>","PeriodicalId":16829,"journal":{"name":"Journal of Physical Organic Chemistry","volume":"38 7","pages":""},"PeriodicalIF":1.9,"publicationDate":"2025-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144171873","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ritu Payal, Manju K. Saroj, Sapan Kumar Jain, R. C. Rastogi
{"title":"In-Depth Insights Into the Excited State Intramolecular Proton Transfer of Biologically Active Triazene Derivatives of Oxazole","authors":"Ritu Payal, Manju K. Saroj, Sapan Kumar Jain, R. C. Rastogi","doi":"10.1002/poc.70018","DOIUrl":"https://doi.org/10.1002/poc.70018","url":null,"abstract":"<div>\u0000 \u0000 <p>Phenyltriaz-1-en-1-yl-4-phenyloxazoles (PTOs) have been identified as photoinduced tautomeric photophysical probes. A series of PTOs has been synthesized and studied for their absorption and fluorescence spectral behavior in different solvent media with varying polarities. PTOs exhibited dual fluorescence behavior and large Stoke's shifts suggesting the presence of tautomeric forms (N* and T*). Dipole moments of PTOs in their excited states were calculated using Bakhshiev, Lippert–Mataga, Reichardt, and Kawski solvatochromic shift methods and were correlated with the theoretical dipole moments for N* and T* forms. The frontier molecular orbitals (HOMO-LUMO) and various physicochemical parameters (χ, η, σ, μ<sub>p</sub>, ω, ΔE<sup>II</sup>, N<sub>max</sub>) were calculated using density functional theory (ground state-(CIS)/B3LYP/6–311++G(d,p)) computations to analyze the excited state intramolecular proton transfer (ESIPT) within these probes. The electrostatic potential (ESP) maps and Mulliken/NBO charges established the electrophilic and nucleophilic sites within molecules and intramolecular proton transfer from one end of the triazeno-bridge to the other end. DFT incorporated dispersion correction (D3(BJ)) accounts for significant van der Waals interactions. In vitro antioxidant activity of PTOs studied using 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assay revealed them as potential antioxidants. Two multi-parametric scales based on solvent polarity, namely, (i) Catálan and (ii) Abboud-Kamlet-Taft, were employed to analyze the acidity and basicity of PTOs in ground and excited states to provide a plausible mechanism for ESIPT.</p>\u0000 </div>","PeriodicalId":16829,"journal":{"name":"Journal of Physical Organic Chemistry","volume":"38 6","pages":""},"PeriodicalIF":1.9,"publicationDate":"2025-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143939549","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Computational Insight to Stereochemical Control on Conjugate Addition of Pyrroloalkenyl Thiol on Activated Alkyne","authors":"Akankasha Yadav, Sunita Siyak, Neelima Gupta","doi":"10.1002/poc.70019","DOIUrl":"https://doi.org/10.1002/poc.70019","url":null,"abstract":"<div>\u0000 \u0000 <p>[3+2] Cycloaddition reaction of thiazolium ylide with activated acetylene does not yield the expected pyrrolothiazole, in contrast to a similar reaction of other <i>N</i>-cycloiminium ylides. Initially formed [3+2] cycloadduct undergoes thiazole ring opening followed by a thiol-yne type nucleophilic addition on second molecule of activated alkyne to give <i>E</i>,<i>Z</i> and/or <i>Z</i>,<i>Z</i> isomers of 1:2 adduct. We have investigated the reaction of thiazolium ylides with alkyl propiolate computationally at DFT level to understand the impact of stereochemical control on mechanistic aspects. Relatively more stable conformer of thiazolium ylide leads to a thermodynamically as well as kinetically preferred diastereomer of the cycloadduct having <i>trans</i> orientation of hydrogen atoms, which restricts the auto-oxidation and facilitates the ring opening. Formation of the <i>Z</i> or <i>E</i> isomer in subsequent thiol-yne reaction depends on the stereochemical control of the allene or allenoate intermediate. Experimentally observed reactivity of thiazolium ylide is computationally rationalized on the basis of the CDFT-based reactivity indices and the stereochemical control on reaction mechanism.</p>\u0000 </div>","PeriodicalId":16829,"journal":{"name":"Journal of Physical Organic Chemistry","volume":"38 6","pages":""},"PeriodicalIF":1.9,"publicationDate":"2025-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143914353","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Onur Erman Doğan, Muhammad Asam Raza, Mohd Farhan, Adnan Ashraf, Zeshan Ali Sandhu, Muhammad Hamayun, Erbil Ağar, Jahan Zaib Arshad, Necmi Dege, Shafiq Ur Rehman
{"title":"Computational and Experimental Exploration of Di-Iodo-Based Schiff Bases as Esterase Inhibitors: Single Crystal and Spectral Insights","authors":"Onur Erman Doğan, Muhammad Asam Raza, Mohd Farhan, Adnan Ashraf, Zeshan Ali Sandhu, Muhammad Hamayun, Erbil Ağar, Jahan Zaib Arshad, Necmi Dege, Shafiq Ur Rehman","doi":"10.1002/poc.70017","DOIUrl":"https://doi.org/10.1002/poc.70017","url":null,"abstract":"<div>\u0000 \u0000 <p>The current study was aimed at synthesizing (<i>E</i>)-2-(((3-hydroxy-4-methylphenyl)imino)methyl)-4,6-diiodophenol (<b>1</b>) and (<i>E</i>)-3-((2-hydroxy-3,5-diiodobenzylidene)amino)-4-methylbenzoate (<b>2</b>). The modern spectral tools like UV–Vis, FTIR, and NMR were used to determine the structures, while a single X-ray diffraction approach was employed to prove that Compound <b>2</b> is orthorhombic and Compound <b>1</b> is triclinic. The 6-31G(d,p) basis set along B3LYP (hybrid functional) was used for the optimisation of synthesized compounds. The energy gaps between various orbitals were estimated using DFT calculations, and a comparative study in terms of different structural parameters was also conducted, which confirmed the correlation between XRD and DFT measurements. Two-dimensional fingerprint plots and Hirshfeld surface analysis were used to further elucidate the different interactions that stabilize the crystal. In vitro and in silico studies were employed to assess the biological potential of these molecules in terms of enzyme inhibition. Compound <b>2</b> depicted 74.17 ± 1.4% and 69.11 ± 1.3% inhibition against AChE and BChE, respectively. The docking score, as well as in vitro studies, demonstrated that Compound <b>2</b> is more potent than Compound 1 against acetylcholine esterase and butyrylcholine esterase.</p>\u0000 </div>","PeriodicalId":16829,"journal":{"name":"Journal of Physical Organic Chemistry","volume":"38 6","pages":""},"PeriodicalIF":1.9,"publicationDate":"2025-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143871621","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Oxidation Reaction of Dihydroazolopyridines: Quantum Chemical Study","authors":"Mariia O. Shyshkina, Serhiy M. Desenko","doi":"10.1002/poc.70016","DOIUrl":"https://doi.org/10.1002/poc.70016","url":null,"abstract":"<div>\u0000 \u0000 <p>The quantum chemical study of the oxidation reaction of the 1,4-dihydropyridine and series of dihydroazolopyridines has been undertaken. The one-electron transfer processes as a key reaction stages and corresponding ionization potentials (I<sub>HetH2</sub> and I<sub>HetH•</sub>) have been discussed. The azole ring effect on the electronic structure of the partially hydrogenated ring in the initial molecules and radicals as well as ionization potentials have been analyzed. The difference in the pyridine-like and pyrrole-like nitrogen atoms effect on the oxidation process has been observed.</p>\u0000 </div>","PeriodicalId":16829,"journal":{"name":"Journal of Physical Organic Chemistry","volume":"38 6","pages":""},"PeriodicalIF":1.9,"publicationDate":"2025-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143871620","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Bozheng Sun, Stefano Pecorario, Elda Sala, Mario Caironi, Michael J. Ferguson, Carlo S. Casari, Rik R. Tykwinski
{"title":"Tetra(4-hexylphenyl) [3]- and [5]Cumulenes","authors":"Bozheng Sun, Stefano Pecorario, Elda Sala, Mario Caironi, Michael J. Ferguson, Carlo S. Casari, Rik R. Tykwinski","doi":"10.1002/poc.70015","DOIUrl":"https://doi.org/10.1002/poc.70015","url":null,"abstract":"<p>The synthesis of [3]- and [5]cumulenes bearing 4-hexylphenyl endgroups, <b>[3]PhHex</b> and <b>[5]PhHex</b>, has been developed. The incorporation of alkyl groups is designed to enhance film formation by improving solubility. Although tetraaryl[3]cumulenes are typically quite stable, the head-to-tail dimerization of <b>[3]PhHex</b> is observed after prolonged storage under ambient conditions, and the dimer is characterized crystallographically. The crystallographic analysis of <b>[5]PhHex</b> in comparison with other tetraaryl[5]cumulenes demonstrates changes in packing as a function of increasing size of the alkyl group. Preliminary characterization of field-effect transistors fabricated with <b>[3]PhHex</b>, in comparison with the parent compound tetraphenyl[3]cumulene <b>[3]Ph</b>, shows poorer performance for <b>[3]PhHex</b> and emphasizes the need to optimize film-forming protocols for new cumulenic semiconductors.</p>","PeriodicalId":16829,"journal":{"name":"Journal of Physical Organic Chemistry","volume":"38 5","pages":""},"PeriodicalIF":1.9,"publicationDate":"2025-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/poc.70015","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143831154","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Mechanistic and Curtin–Hammett Studies of the 1O2 Oxidation of a Prenyl Phenol and Phenolate Anion","authors":"Akshaya Iyer, Lloyd Lapoot, Alexander Greer","doi":"10.1002/poc.70014","DOIUrl":"https://doi.org/10.1002/poc.70014","url":null,"abstract":"<div>\u0000 \u0000 <p>The Curtin–Hammett principle, widely recognized in thermal reactions, has been extended to photosensitization processes in this study, providing new insights into the reactivity of photogenerated singlet oxygen (<sup>1</sup>O<sub>2</sub>) with phenol and phenolate anion species. Here, we explore mechanistic and Curtin–Hammett studies of the equilibrium between the phenol and phenolate anion forms of a prenylated natural product, prenylphloroglucinol. This study uses density functional theory (DFT) to examine phenol and phenolate anion-quenching pathways of <sup>1</sup>O<sub>2</sub> showing distinct pathways for each form. In the phenolate anion, <sup>1</sup>O<sub>2</sub> is quenched to form a peroxy anion. In contrast, in the phenol form, <sup>1</sup>O<sub>2</sub> leads to a potent epoxidizing agent in a seemingly pro-oxidant path. An <i>iso</i>-hydroperoxyhydrofuran intermediate is proposed to be key in the epoxidation. Meanwhile, the phenolate anion cyclizes and protonates forming a comparatively benign hydroperoxyhydrofuran species. The phloroglucinol is next to the C-prenyated group directs the reaction pathway towards the formation of a dihydrobenzofuran, deviating from the conventional <sup>1</sup>O<sub>2</sub> “ene” reaction mechanism and the production of allylic hydroperoxides typically observed in trisubstituted alkenes.</p>\u0000 </div>","PeriodicalId":16829,"journal":{"name":"Journal of Physical Organic Chemistry","volume":"38 5","pages":""},"PeriodicalIF":1.9,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143698891","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"The Influence of Homoring Competition Effect of Substituents on the Nonclassical Hydrogen Bonding Properties in Diarylnitroketone","authors":"Hua Luo, Chao-Tun Cao, Chenzhong Cao","doi":"10.1002/poc.70013","DOIUrl":"https://doi.org/10.1002/poc.70013","url":null,"abstract":"<div>\u0000 \u0000 <p>Nonclassical hydrogen bond (NCHB) as a weak interaction force not only plays an important role in organic conversion and catalysis but also has significant implications for understanding and predicting the properties of compounds. At present, the influence of homoring competition effect of substituents on the intramolecular properties of NCHB has not been studied. In this work, 51 diphenylnitroketone XArCH=N(O)ArY (XPNY) compounds containing different substituents were chosen as model molecules, the bond energy (<i>E</i><sub>HB</sub>) in CH⋯O and aromaticity of quasi-aromatic ring (PDI<sub>Q</sub>) were computed, and the chemical shifts <i>δ</i><sub>H(CH⋯O)</sub> of <sup>1</sup>H NMR in CH⋯O were collected or measured. This work focuses on analyzing the NCHB CH⋯O hydrogen bond in compounds XPNY and explored the influence of homoring competition effect of substituents on the energy <i>E</i><sub>HB</sub> of CH⋯O and chemical shift value <i>δ</i><sub>H(CH⋯O)</sub>. The results show that (1) the chemical shift values <i>δ</i><sub>H(CH⋯O)</sub> of CH⋯O in XPNY are abnormally large, and the values of <i>E</i><sub>HB</sub> are 14.15–15.51 kJ/mol, lower than 16.74 kJ/mol, which is consistent with the characteristics of intramolecular NCHB. Therefore, it can be considered that the CH⋯O hydrogen bonds are NCHB in XPNY. (2) The substituent X in compound XPNY exhibits the homoring competition effect. (3) The aromaticity of quasi-aromatic ring Q is the main factor affecting the <i>E</i><sub>HB</sub>. The substituent X affects the <i>E</i><sub>HB</sub> and <i>δ</i><sub>H(CH⋯O)</sub> along different paths. This study can help understanding the impact of substituent effects on NCHB in depth.</p>\u0000 </div>","PeriodicalId":16829,"journal":{"name":"Journal of Physical Organic Chemistry","volume":"38 5","pages":""},"PeriodicalIF":1.9,"publicationDate":"2025-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143689968","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Calculation of the Energy of Intramolecular Hydrogen Bonds Using the Clipping Method: The Case of ω-X-1-Alkanols, X(CH2)nOH","authors":"Robert E. Rosenberg","doi":"10.1002/poc.70011","DOIUrl":"https://doi.org/10.1002/poc.70011","url":null,"abstract":"<div>\u0000 \u0000 <p>Although the energies of intermolecular hydrogen bonds, E<sub>HB</sub>, can be ascertained by a variety of approaches, there is not a general method to accurately determine the energies for intramolecular hydrogen bonds, E<sub>IMHB</sub>. Structures for compounds X(CH<sub>2</sub>)<sub>n</sub>OH {X = F, OH, NH<sub>2</sub>, Cl, Br, SH; <i>n</i> = 4–5} are calculated and then “clipped” to form complexes CH<sub>3</sub>CH<sub>2</sub>X•CH<sub>3</sub>CH<sub>2</sub>OH such that the critical geometric, spectroscopic, and electron density features are preserved. The E<sub>IMHB</sub> of the parent molecule is assumed to equal the E<sub>HB</sub> of the complex. Of the previous methods of determining E<sub>IMHB</sub>, the molecular tailoring approach (MTA) comes closest to the values from this work with the differences due to incomplete cancellation of conformational effects in the MTA. In general, parametric methods fare poorly, only being effective for groups of similar molecules. The <i>cis</i>–<i>trans</i> and isodesmic approaches are of limited value for longer carbon chains due to conformational strain.</p>\u0000 </div>","PeriodicalId":16829,"journal":{"name":"Journal of Physical Organic Chemistry","volume":"38 5","pages":""},"PeriodicalIF":1.9,"publicationDate":"2025-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143690122","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Polybenzenoid Hydrocarbons in the S1 State: Simple Structural Motifs Predict Electronic Properties and (Anti)aromaticity","authors":"Fatimah Khaleel, Sabyasachi Chakraborty, Renana Gershoni-Poranne","doi":"10.1002/poc.70012","DOIUrl":"https://doi.org/10.1002/poc.70012","url":null,"abstract":"<p>Polybenzenoid hydrocarbons (PBHs) are widely studied for their semiconductive properties and potential applications in organic electronics and photochemistry. Understanding their behavior in excited states is crucial for optimizing their performance in these applications. Here, we computationally investigate a dataset of 43 unbranched <i>cata</i>-condensed PBHs in their first singlet excited state (S₁), revealing clear correlations between molecular structure and electronic properties. By analyzing these molecules through their annulation patterns—specifically the arrangement of linear (L) and angular (A) tricyclic subunits and tetracyclic zigzag (Z) and curve (C) motifs—we establish a predictive hierarchy (L > Z > C > A) for the location of unpaired electrons and Baird-antiaromaticity. This structural approach enables semiquantitative prediction of key properties, including excitation energies, magnetic response, and singlet fission capability. Notably, we find that singlet fission propensity is dependent on both the length of the Longest L sequence and the position of the L motifs within the sequence. These insights, derived from the analysis of small tri- and tetracyclic components and validated on larger systems, provide a practical framework for understanding and designing PBH-based materials.</p>","PeriodicalId":16829,"journal":{"name":"Journal of Physical Organic Chemistry","volume":"38 5","pages":""},"PeriodicalIF":1.9,"publicationDate":"2025-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/poc.70012","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143689966","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}