Vibrational Spectroscopy最新文献

{"title":"Raman retrieval from BCARS spectra under heavy noise using TCN-BiGRU model","authors":"Syed Sikandar Shah ,&nbsp;Yu Long ,&nbsp;Syed Zain Ul Abideen ,&nbsp;Kangwen Yang","doi":"10.1016/j.vibspec.2026.103919","DOIUrl":"10.1016/j.vibspec.2026.103919","url":null,"abstract":"<div><div>Coherent Anti-Stokes Raman Scattering (CARS) spectroscopy enables label-free chemical imaging but is strongly affected by non-resonant background (NRB) and measurement noise, which complicate Raman signal retrieval. We present TCN-BiGRU, a hybrid deep learning architecture that combines a Temporal Convolutional Network (TCN) with Bidirectional Gated Recurrent Unit (BiGRU) for long-range spectral context. The proposed model is trained using simulated CARS data with NRB and controlled noise added to emulate challenging experimental conditions, with the resonant-to-NRB ratio R sampled during training. For performance evaluation, we sweep <em>R</em> from 1.0 down to 0.01 and test under severe noise contamination, including Gaussian noise (standard deviation σ up to 0.1) and low-count Poisson noise (λ down to 10²). These stress-test conditions show that the model preserves peak positions and relative intensities while suppressing the NRB to produce near-flat baselines. Compared with existing models such as SpecNet and BiLSTM, TCN-BiGRU achieves lower mean squared error (MSE) and detects Raman peaks more reliably across different <em>R</em> and noise settings, keeping peak locations and relative heights closer to the ground-truth resonant Raman spectrum while reducing noise-induced distortions. These results suggest that TCN-BiGRU is a promising approach for simplifying BCARS analysis in NRB-dominant, low-SNR conditions, providing a single-step route to Raman spectra without a separately measured NRB spectrum.</div></div>","PeriodicalId":23656,"journal":{"name":"Vibrational Spectroscopy","volume":"144 ","pages":"Article 103919"},"PeriodicalIF":3.1,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147858995","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Raman spectroscopic study of carbon nanomaterial synthesis under varying gas environments on Cu, Ni, Fe, and Ga catalysts via thermal and plasma-enhanced CVD of methane","authors":"Zane M. Ronau,&nbsp;Gamini Sumanasekera","doi":"10.1016/j.vibspec.2026.103916","DOIUrl":"10.1016/j.vibspec.2026.103916","url":null,"abstract":"<div><div>This study investigates methane pyrolysis, both with and without radio-frequency plasma, to simultaneously synthesize high-value nanostructured solid carbon (s-C) materials on Cu, Ni, Fe, and Ga catalysts via chemical vapor deposition (CVD). Raman spectroscopy was employed to assess the optimum growth conditions including the influence of hydrogen during the CVD and plasma-enhanced CVD (PECVD) processes. With immediate characterization prior to transfer, mono-layer graphene grown on copper was readily identified by the presence of a split G-band (G and D′), reflecting its conformal adherence to the substrate and structural defects. In contrast, the D’ – band was not present with the few or multi-layer graphene grown on nickel. This difference comes in part due to the relatively large crystalline domain size associated with well-stacked multilayer graphene and the relatively low defect density in the graphene layers. This observation was further supported by the 2D-band profile, which exhibited a sharp single peak for mono-layer graphene, in contrast to the broader, multi-component peak characteristic of multi-layer graphene. The abundance ratio of the semiconducting and metallic single-walled carbon nanotubes grown using Fe catalysts was inferred comparing the intensity ratio of the G⁺ and G⁻ bands. When Ga was used as a low-melting-point catalyst, PECVD at relatively low temperatures yielded a s-C product with a G-to-D band intensity ratio of approximately 1, indicative of carbon microtube formation. Overall, the effects of the catalyst, plasma, temperature, pressure, and the gas environment on s-C growth were investigated using Raman spectroscopy.</div></div>","PeriodicalId":23656,"journal":{"name":"Vibrational Spectroscopy","volume":"144 ","pages":"Article 103916"},"PeriodicalIF":3.1,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147858994","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Vibrational spectroscopic fingerprinting and DFT-assisted band assignment of the resazurin–resorufin redox transformation in Escherichia coli","authors":"Twinkle Soni ,&nbsp;Diana E. Bedolla ,&nbsp;Francesco D’Amico ,&nbsp;Shobha Shukla ,&nbsp;Bayden R. Wood","doi":"10.1016/j.vibspec.2026.103917","DOIUrl":"10.1016/j.vibspec.2026.103917","url":null,"abstract":"<div><div>Resazurin is a widely used redox-active dye whose reduction to resorufin forms the basis of numerous biological viability and metabolic assays. Despite its extensive use, a detailed vibrational spectroscopic characterization of the resazurin–resorufin redox transformation, supported by rigorous molecular-level band assignments, particularly in biologically relevant environments, remains lacking. Here, we investigate vibrational spectroscopic monitoring of the resazurin–resorufin redox transformation during bacterial metabolic activity in an <em>Escherichia coli</em> strain, using a correlative approach that integrates Raman spectroscopy, infrared (IR) spectroscopy, polarization-dependent Raman measurements, and density functional theory (DFT) simulations. Raman and IR spectra collected during the redox process show clear and reproducible changes in both band positions and relative intensities. In particular, a consistent Raman band shift from 1643 to 1652 cm⁻¹ is observed, along with pronounced intensity redistribution in low-frequency modes associated with ring deformation and aromatic skeletal vibrations. Quantitative analysis of selected Raman band ratios in the 480–450, 1179–1149, and 1450–1397 cm⁻¹ regions provides a simple and robust way to follow the progression of the redox transformation. Polarization-dependent Raman measurements further reveal changes in vibrational symmetry and molecular polarizability as reduction proceeds. DFT simulations reproduce the key experimental features and enable assignment of the observed Raman bands to specific molecular motions. UV–Visible and fluorescence measurements provide independent confirmation of the redox state of the dye. Together, this work establishes a DFT-supported vibrational framework for monitoring the resazurin–resorufin redox transformation in biological systems, providing a molecular-level basis for future spectroscopic studies employing resazurin as a redox reporter.</div></div>","PeriodicalId":23656,"journal":{"name":"Vibrational Spectroscopy","volume":"144 ","pages":"Article 103917"},"PeriodicalIF":3.1,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147858993","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Serum fourier infrared spectroscopy profiling integrated with machine learning: A novel strategy for rapid classification diagnosis chronic obstructive pulmonary disease","authors":"Ziyi Fang ,&nbsp;Hui Zhao ,&nbsp;Xiangxiang Zheng ,&nbsp;Nazhaketi Simayili ,&nbsp;Zihan Xia ,&nbsp;Renyong Lin ,&nbsp;Guodong Lü","doi":"10.1016/j.vibspec.2026.103920","DOIUrl":"10.1016/j.vibspec.2026.103920","url":null,"abstract":"<div><div>Chronic Obstructive Pulmonary Disease (COPD) is a widespread, progressive respiratory condition marked by ongoing airflow limitation, significantly impacting global public health and socioeconomic progress. Currently, diagnosing COPD is challenging due to early detection difficulties and lack of specificity. However, the serum Fourier infrared spectroscopy (FTIR) spectrum offers a quick method that captures metabolic spectral features, presenting a new diagnostic approach. This study evaluates the potential of diagnosing COPD using serum FTIR spectra combined with principal component analysis-linear discriminant analysis (PCA-LDA), support vector machine linear (SVM-linear), SVM- radial basis function (SVM-RBF), K-nearest neighbors (KNN) and decision tree (DT). Differences were observed at the wavelengths 1078, 1172, 1240, 1310, 1396, 1452, 1538, 1639, 2873, 2928, 2958, and 3278 cm⁻¹ in the serum FTIR spectra of the COPD group compared to healthy individuals. By utilizing the PCA-LDA algorithm within the 2800–3080 cm⁻¹ range, the classification accuracy was maximized. When paired with serum FTIR, this method achieved 100% accuracy, indicating promising potential for the use of serum FTIR spectroscopy and PCA-LDA in COPD detection.</div></div>","PeriodicalId":23656,"journal":{"name":"Vibrational Spectroscopy","volume":"144 ","pages":"Article 103920"},"PeriodicalIF":3.1,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147858991","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Serum Raman spectroscopy combined with PCA-CNN model for the diagnosis of hepatitis B, liver cirrhosis, and Hepatocellular Carcinoma","authors":"Baiyun Wang ,&nbsp;Liang Zhang ,&nbsp;Guohua Wu ,&nbsp;Longfei Yin ,&nbsp;Xuewen Long ,&nbsp;Ting Mei ,&nbsp;Yishu Tang","doi":"10.1016/j.vibspec.2026.103896","DOIUrl":"10.1016/j.vibspec.2026.103896","url":null,"abstract":"<div><div>Cancer poses a serious threat to global public health, and early and accurate diagnosis is crucial for improving patient prognosis and reducing mortality rates. In this study, we used serum Raman spectroscopy combined with PCA-CNN model to diagnose three types of liver diseases, including hepatitis B, liver cirrhosis, and Hepatocellular Carcinoma. Established a serum Raman spectroscopy database containing three types of diseases and healthy controls. Compared with traditional methods such as SVM and PCA-LDA, PCA-CNN has higher efficiency and accuracy. Based on the collected 327 samples, PCA was used to extract features with a 95 % contribution rate and the 1D-CNN model was used for four classification. After five fold cross validation, the overall weighted average accuracy was 83.79 %. When the precision was 0.85,specificity was 0.95, F1 was 0.84, and AUC was 0.94, it improved by at least 4 % compared to traditional classification methods such as SVM. It provides a new method for rapid and non-invasive identification of multiple selected liver diseases, and contributes to clinical diagnosis.</div></div>","PeriodicalId":23656,"journal":{"name":"Vibrational Spectroscopy","volume":"143 ","pages":"Article 103896"},"PeriodicalIF":3.1,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147399346","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluation of pesticide acetamiprid on Candida parapsilosis biofilm using Raman spectroscopy","authors":"Kursad Osman Ay ,&nbsp;Bükay Yenice Gürsu ,&nbsp;Betül Yılmaz Öztürk ,&nbsp;İlknur Dağ","doi":"10.1016/j.vibspec.2026.103893","DOIUrl":"10.1016/j.vibspec.2026.103893","url":null,"abstract":"<div><div>Acetamiprid is a widely used pesticide recommended for its relatively low toxicity; however, prolonged application may cause extensive environmental problems. Reports have highlighted its adverse effects on non-target organisms and its potential to alter soil microbial activity due to substantial environmental exposure. Moreover, pesticide residues may enter the human body through various routes, influencing the microbiota. <em>Candida</em> species, normally commensal on mucosal surfaces, can cause opportunistic infections under immunocompromised conditions. Among them, <em>C. parapsilosis</em> has emerged as one of the most frequently isolated yeast species in recent fungal infections, primarily due to its biofilm-forming capacity. In this study, the impact of acetamiprid on <em>C. parapsilosis</em> biofilm was assessed using Raman spectroscopy, a label-free technique with advantages such as high sensitivity, specificity, and the ability to quantitatively reveal biochemical changes in biofilm structures. Biofilms were developed on glass slides and subsequently treated with acetamiprid, while untreated biofilms served as controls. Raman spectral analysis demonstrated significant reductions in band intensities related to proteins, lipids, polysaccharides, and DNA in acetamiprid-treated samples compared to controls. These findings indicate that Raman spectroscopy can serve as a powerful approach to rapidly and effectively examine pesticide effects on biofilms and provide insights into potential antibiofilm strategies. Furthermore, the data raise the possibility of considering acetamiprid for novel antibacterial applications, combination therapies, and implications in food and agricultural safety. Nevertheless, <em>in vitro</em> findings should be supported with comprehensive toxicological studies to validate the broader impact of such applications.</div></div>","PeriodicalId":23656,"journal":{"name":"Vibrational Spectroscopy","volume":"143 ","pages":"Article 103893"},"PeriodicalIF":3.1,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146080491","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Infrared spectroscopy of binary nucleobase mixtures: Vibrational fingerprints of intermolecular interactions","authors":"Ana L.F. de Barros ,&nbsp;Enio Frota da Silveira","doi":"10.1016/j.vibspec.2026.103885","DOIUrl":"10.1016/j.vibspec.2026.103885","url":null,"abstract":"<div><div>Nitrogenous bases such as adenine, guanine, cytosine, and thymine are central to molecular biology, yet their intermolecular interactions in the solid state remain incompletely characterized. In this work, we present a systematic FTIR study of all six binary mixtures of canonical nucleobases under ambient solid-state conditions, comparing the experimental spectra of the mixtures with the arithmetic mean of their pure components. Significant non-linear spectral deviations are observed, including the appearance of new bands, shifts in peak position, changes in intensity, and modifications of band shape; pronounced effects are particularly noted in both the 1700–1500 cm⁻¹ and fingerprint (∼1500–600 cm⁻¹) regions. Representative interaction-induced wavenumber shifts on the order of 5–20 cm⁻¹ are observed for key vibrational modes associated with C<img>O, C<img>N, and ring deformation bands, depending on the specific nucleobase pairing<em>.</em> They provide direct spectroscopic evidence that intermolecular interactions, rather than simple additive behavior, govern the vibrational response of binary nucleobase assemblies. These effects indicate that hydrogen bonding, π–π stacking, and local environment perturbations strongly influence vibrational behavior when different base molecules coexist. Our analysis builds upon established solid-state spectroscopic assignments of individual nucleobases and previous investigations of non-irradiated binary systems, extending them through a systematic, comparative experimental approach. By mapping and cross-comparing all six binary combinations, this study demonstrates that each pairing generates a distinct non-linear vibrational fingerprint, reflecting base-specific intermolecular organization and supramolecular packing. Such results serve as a chemical/ biochemical baseline for understanding intermolecular interactions in nucleobase mixtures. Importantly, this baseline provides a robust reference for disentangling purely interaction-driven vibrational effects from radiation-induced chemical modifications in future studies. In this context, the present data set establishes a reference framework for future comparisons with irradiated systems, supporting investigations relevant to supramolecular chemistry, molecular recognition, and prebiotic chemistry. Moreover, the identification of interaction-sensitive infrared markers contributes to the interpretation of spectroscopic observations of complex organic matter in astrochemical and cosmic environments.</div></div>","PeriodicalId":23656,"journal":{"name":"Vibrational Spectroscopy","volume":"143 ","pages":"Article 103885"},"PeriodicalIF":3.1,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145996498","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Resonance Raman spectroscopy of NADH, NAD+ , ferredoxin and cytochrome c in Sporomusa ovata and Clostridium carboxidivorans for microbial electrosynthesis applications","authors":"Adolf Krige ,&nbsp;Ulrika Rova ,&nbsp;Paul Christakopoulos ,&nbsp;Lisbeth Olsson ,&nbsp;Kerstin Ramser","doi":"10.1016/j.vibspec.2026.103895","DOIUrl":"10.1016/j.vibspec.2026.103895","url":null,"abstract":"<div><div>Microbial electrosynthesis (MES) offers a sustainable alternative for the production of platform chemicals from CO₂. Label-free Raman spectroscopy can provide direct insights into biomolecular changes in MES, reflecting metabolic activity and production. In this study defined co-cultures of electro-active bacteria, i.e. <em>Sporomusa ovata</em> and <em>Clostridium carboxidivorans,</em> were investigated by confocal resonance Raman micro-spectroscopy tuned to 532 nm to gain insights into the microbial processes of biomarkers involved in the Wood-Ljundahl pathway. The results were correlated to high-performance liquid chromatography (HPCL) and optical density measurements regarding the production rate of acetate, butyrate, ethanol and butanol. Pre-processed difference Raman spectra of co-cultures from <em>S. ovata</em> and <em>C. carboxidivorans</em> at ratios 1:10, 10:1, and 1:1 were compared to monocultures on day 1 and 2, revealing substantial variations in Raman intensity and thus the relative metabolic activity of NADH, NAD⁺, ferredoxin and cytochrome c. Such information may point to high metabolic activity at the start of acetate, butyrate, ethanol, and butanol production followed by a steady state at day four. This was verified by Raman difference spectra between fresh cultures and &gt; 4 days old cultures, indicating a similar degree of metabolic activity after a certain time during ongoing production. Interestingly, the Raman spectra did not reveal any differences in metabolism depending on feedstocks, i.e. CO₂ and H₂ versus betaine or different ratios of co-cultures that were significantly more productive. This qualitative study demonstrates that resonance Raman spectroscopy is a viable tool for metabolic investigations of microbial electrosynthesis systems with potential for <em>in situ</em> investigations.</div></div>","PeriodicalId":23656,"journal":{"name":"Vibrational Spectroscopy","volume":"143 ","pages":"Article 103895"},"PeriodicalIF":3.1,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146173981","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ageing of Prussian blue oil paints: The effect of the pigment studied using attenuated total reflection Fourier transform infrared spectroscopy","authors":"Suzanne Reus ,&nbsp;Lise Krebbers ,&nbsp;Ana Radosavljević ,&nbsp;Maarten R. van Bommel ,&nbsp;Klaas Jan van den Berg","doi":"10.1016/j.vibspec.2026.103899","DOIUrl":"10.1016/j.vibspec.2026.103899","url":null,"abstract":"<div><div>Degradation phenomena such as cracking and paint loss have been observed in dark blue paint strokes in Vincent van Gogh's paintings. Analysis of several samples taken from such paint strokes has confirmed that the paint contains Prussian blue pigment, linseed oil and a small amount of beeswax. Research into the chemical and mechanical processes taking place during the ageing of this paint is required to understand the cause behind the degradation phenomena. Therefore, attenuated total reflection Fourier transform infrared spectroscopy was used to study the chemical changes during the artificial ageing of oil paint reconstructions and correlate those changes with visual observations of the paints’ degradation. The influence of different pigments, as well as the pigment volume concentration and the presence of beeswax on the ageing of the reconstructions was investigated. The tested pigments include both soluble and insoluble Prussian blue prepared according to historical 19th-century recipes, modern Prussian blues, and a cobalt blue pigment. Ester hydrolysis was observed during artificial ageing for both cobalt blue and Prussian blue paints, but this effect was much larger for the latter. Additionally, NH₃ adsorption and its subsequent conversion to NH₄⁺ were observed in most Prussian blue reconstructions, which is expected to contribute to the increased ester hydrolysis rate in these paints and the formation of free fatty acid efflorescence. The type of Prussian blue pigment was found to influence the capability of NH₃ adsorption and the formation of fatty acid efflorescence, as this was not found in all reconstructions.</div></div>","PeriodicalId":23656,"journal":{"name":"Vibrational Spectroscopy","volume":"143 ","pages":"Article 103899"},"PeriodicalIF":3.1,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147399344","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Complete vibrational assignments of phosphatidylcholine combining FTIR and FT-Raman spectra with DFT and SQMFF calculations","authors":"Sonia B. Diaz ,&nbsp;Davide Romani ,&nbsp;Silvia Antonia Brandán","doi":"10.1016/j.vibspec.2026.103898","DOIUrl":"10.1016/j.vibspec.2026.103898","url":null,"abstract":"<div><div>Complete assignments of phosphatidylcholine (PC) have been performed combining the FTIR and FT-Raman spectra with density functional theory (DFT) calculations and the scaled quantum mechanical force field (SQMFF) methodology. Here, the effects of water and of alkyl R and R’ chains on the main vibration modes of two anhydrous (C1 and C1-R) and two mono-hydrated (C2 and C2-R) species of PC have been analysed considering the phosphate groups with local <em>C</em>_{<em>2 V</em>} and <em>C</em>_{<em>3 V</em>} symmetries. Then, the main scaled force constants have been reported. Stabilities, reactivities and descriptors of species have been evaluated by using atomic charges, molecular electrostatic potentials (MEP), natural bond orbital (NBO), atoms in molecules (AIM) and frontier orbital studies. Thus, substitution of H atoms by R and R′ groups in both C1-R and C2-R species leads to increased molecular volume (V) and polarizability (α), while the dipole moment decreases. Different intra-molecular interactions predicted by NBO and AIM calculations could justify such changes. Besides, the presence of water molecules in C2-R species increases its α value. Mulliken charges and the MEP energy increase when the alkyl R and R’ chains increase while C2 shows lower MEP energy. AIM studies show multiple interactions in both hydrophilic and hydrophobic moieties that eventually increase the stabilities of species being C2 and C2-R more stable than C1 and C1-R, suggesting that the water molecules stabilize both mono-hydrated species. The MEP, NBO, and the ω, χ, and μ descriptors account for the higher reactivity of C1-R compared with C1, C2, and C2-R.</div></div>","PeriodicalId":23656,"journal":{"name":"Vibrational Spectroscopy","volume":"143 ","pages":"Article 103898"},"PeriodicalIF":3.1,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147399343","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}