A graphene quantum dots–glassy carbon electrode-based electrochemical sensor for monitoring malathion

• Sanju Tanwar,
• Aditi Sharma and
• Dhirendra Mathur

Beilstein J. Nanotechnol. 2023, 14, 701–710, doi:10.3762/bjnano.14.56

• , differential pulse voltammetry experiments were conducted with 0.1 M phosphate-buffered saline at pH 7. Results and Discussion Characterization of graphene quantum dots The UV–vis absorption spectrum of the GQDs in distilled water is depicted in Figure 2a, which shows two prominent absorption peaks around 270

• and 320 nm, in agreement with the data previously reported [30][31]. The shoulder at 270 nm is probably caused by π–π* transition of the C=C bonds, and the absorption hump at 320 nm is likely caused by n–π* transitions of the C=O bonds. As shown in Figure 2b, when the graphene quantum dot suspension

• shows the presence of only carbon and oxygen in the GQDs with 82.35 atom % carbon and 17.65 atom % oxygen. Figure 5a shows the functional groups present on the surface of the GQDs measured using FTIR infrared spectroscopy. The broad absorption band at 3430 cm−1 corresponds to stretching vibrations of O

Humidity-dependent electrical performance of CuO nanowire networks studied by electrochemical impedance spectroscopy

• Jelena Kosmaca,
• Juris Katkevics,
• Jana Andzane,
• Raitis Sondors,
• Liga Jasulaneca,
• Raimonds Meija,
• Kiryl Niherysh,
• Yelyzaveta Rublova and
• Donats Erts

Beilstein J. Nanotechnol. 2023, 14, 683–691, doi:10.3762/bjnano.14.54

• compositions aligned by DEP [25]. In some of these works, electrochemical impedance spectroscopy (EIS) was used as an effective tool to study the effects of chemical and physical absorption of water on the nanostructured surfaces of active CuO elements of the systems [23][24]. To the best of our knowledge, the

Investigations on the optical forces from three mainstream optical resonances in all-dielectric nanostructure arrays

• Guangdong Wang and
• Zhanghua Han

Beilstein J. Nanotechnol. 2023, 14, 674–682, doi:10.3762/bjnano.14.53

• two components (i.e., scattering force and gradient force [1]) and the motion of tiny particles within an optical field is determined by both of them. The scattering force originates from the photon momentum transferred to the particle caused by the scattering and absorption of photons. As a result

• to effectively capture subwavelength nanoparticles by overcoming the diffraction limit [4], which has aroused broad research interest. However, due to the high loss of metals, the Joule heating effect caused by the absorption of light leads to increasing temperatures of plasmonic nanotweezers, and

• when one designs nano-optical tweezers system to capture nanoscale particles. The low absorption losses, high laser power damage threshold as well as the large optical force that can be achieved with lossless all-dielectric nanostructures provide a better choice compared to the metallic counterpart in

Metal-organic framework-based nanomaterials as opto-electrochemical sensors for the detection of antibiotics and hormones: A review

• Akeem Adeyemi Oladipo,
• Saba Derakhshan Oskouei and
• Mustafa Gazi

Beilstein J. Nanotechnol. 2023, 14, 631–673, doi:10.3762/bjnano.14.52

• limit of detection for SMZ is 0.655 μM, and the Ln-MOF luminescence is strongly quenched, with a quenching constant of 4.60 × 104 M−1. They proposed two potential mechanisms for quenching (inner-filter effect and electron transfer). The overlap between the antibiotic’s absorption spectrum and the Ln

• (acceptor) within 10 nm in a non-radiative manner. In general, the degree of overlap between the fluorophore’s fluorescence emission spectrum and the analyte’s absorption spectrum, the relative orientation of the fluorophore and analyte dipoles, and the distance between them affect the rate of energy

• primary IFE is the absorption of the fluorophore’s excitation by the analyte, the secondary IFE is the absorption of the fluorophore’s emission [50]. Yazhini et al. recently developed a highly stable inner filter effect-based Zn-luminescent MOF for the selective detection of tetracycline [48]. They were

Titania nanoparticles for photocatalytic degradation of ethanol under simulated solar light

• Evghenii Goncearenco,
• Iuliana P. Morjan,
• Claudiu Teodor Fleaca,
• Florian Dumitrache,
• Elena Dutu,
• Monica Scarisoreanu,
• Valentin Serban Teodorescu,
• Alexandra Sandulescu,
• Crina Anastasescu and
• Ioan Balint

Beilstein J. Nanotechnol. 2023, 14, 616–630, doi:10.3762/bjnano.14.51

• converted to absorption data using the Kubelka–Munk function F(R). For the XPS analyses we employed an ESCALAB Xi+ (Thermo SCIENTIFIC Surface Analysis) apparatus with an Al Kα radiation source (hν = 1486.2 eV) using the C 1s level (284.4 eV) as the energy reference. The superficial chemical compositions as

ZnO-decorated SiC@C hybrids with strong electromagnetic absorption

• Liqun Duan,
• Zhiqian Yang,
• Yilu Xia,
• Xiaoqing Dai,
• Jian’an Wu and
• Minqian Sun

Beilstein J. Nanotechnol. 2023, 14, 565–573, doi:10.3762/bjnano.14.47

• Liqun Duan Zhiqian Yang Yilu Xia Xiaoqing Dai Jian'an Wu Minqian Sun State Key Laboratory of Disaster Prevention & Mitigation of Explosion & Impact, Army Engineering University of PLA. Nanjing 210007, P.R. China 10.3762/bjnano.14.47 Abstract A novel strategy is provided to improve the absorption

• that crystalline ZnO particles adhere to the surface of amorphous carbon, and the ZnO content increases as a function of a dosage of ZnNO3·6H2O. The as-prepared SiC@C-ZnO hybrids exhibit effective electromagnetic absorption, which is related to a synergy effect of different dielectric loss processes

• . The minimum reflection loss reached −65.4 dB at 11 GHz at a sample thickness of 3.1 mm, while the effective absorption bandwidth (EAB) reached 7 GHz at a sample thickness of 2.56 mm. Furthermore, the EAB of the samples can also cover the whole X band and Ku band at small sample thicknesses (2.09–3.47

SERS performance of GaN/Ag substrates fabricated by Ag coating of GaN platforms

• Magdalena A. Zając,
• Bogusław Budner,
• Malwina Liszewska,
• Bartosz Bartosewicz,
• Łukasz Gutowski,
• Jan L. Weyher and
• Bartłomiej J. Jankiewicz

Beilstein J. Nanotechnol. 2023, 14, 552–564, doi:10.3762/bjnano.14.46

• absorption spectra of the GaN platform and the GaN/Ag SERS substrates fabricated using MS and PLD at different temperatures are shown in Figure 5. The spectrum of GaN shows the typical spectral shape of a broadband semiconductor with an absorption edge around 365 nm (3.4 eV). The spectra of all GaN/Ag

• substrates show a strong absorption of light in the visible range, which is related to the phenomenon of surface plasmon resonance (SPR). The strongly nanoscale-rough surface causes a significant extension of the spectral range of SPR in comparison to thin silver layers. Based on the comparison of the light

• absorption level for samples in a given series, it can be seen that an increase in the amount of deposited metal causes a decrease in light absorption, which is related to a decrease in surface roughness and the filling of the nanoporous GaN structure with silver. SERS performance of fabricated of GaN/Ag

Carbon nanotube-cellulose ink for rapid solvent identification

• Tiago Amarante,
• Thiago H. R. Cunha,
• Claudio Laudares,
• Ana P. M. Barboza,
• Ana Carolina dos Santos,
• Cíntia L. Pereira,
• Vinicius Ornelas,
• Bernardo R. A. Neves,
• André S. Ferlauto and
• Rodrigo G. Lacerda

Beilstein J. Nanotechnol. 2023, 14, 535–543, doi:10.3762/bjnano.14.44

• rapid test, identification, and monitoring of liquid samples in various fields such as fuel adulteration, water quality, solvents, and beverages [6][7][8][9]. Usually, the testing of liquids requires conventional analytical techniques such as absorption/emission spectroscopy (AAS/AES), X-ray

The origin of black and white coloration of the Asian tiger mosquito Aedes albopictus (Diptera: Culicidae)

• Manuela Rebora,
• Gianandrea Salerno,
• Silvana Piersanti,
• Alexander Kovalev and
• Stanislav N. Gorb

Beilstein J. Nanotechnol. 2023, 14, 496–508, doi:10.3762/bjnano.14.41

• weakest at perpendicular illumination. In UV spectral range, the light scattering has no specific trends (corresponding to, e.g., Rayleigh scattering), though absorption by molecules with aromatic groups might modulate the reflection. There are no pigments in the white scales (Figure 5d), so interference

• illumination/observation configuration; (2) light scattering, which might be subdivided in (a) Rayleigh scattering on nanostructures, (b) scattering on partially regular micro- and nanostructures, and (c) thin film interference scales; (3) selective absorption by various molecules present in the cuticle; and

• the black scales (Figure 5b) because of the partial light absorption by melanin. Light absorption Some substances absorbing UV light are present even in the white scales. They attenuate the reflection in the UV–visible, but not in the red–IR, spectral range. Multiple refractions and reflections

Specific absorption rate of randomly oriented magnetic nanoparticles in a static magnetic field

• Ruslan A. Rytov and
• Nikolai A. Usov

Beilstein J. Nanotechnol. 2023, 14, 485–493, doi:10.3762/bjnano.14.39

• = 0–800 Oe. The specific absorption rate (SAR) of the assemblies is calculated depending on the angle between the directions of the ac and dc magnetic fields. For the case of an inhomogeneous dc magnetic field created by two opposite magnetic fluxes, the spatial distribution of the SAR in the vicinity

• hyperthermia; magnetic nanoparticles; magnetic particle imaging; specific absorption rate; static magnetic field; Introduction Magnetic nanoparticles, mainly iron oxides, are promising materials for the diagnosis and therapy of oncological diseases [1][2][3]. Important fields of application of magnetic

• amplitude, Hac = 100–200 Oe [1][7][8]. In magnetic hyperthermia, magnetic nanoparticles are introduced into the tumor and heated by absorbing the energy of the ac magnetic field. The intensity of heat release is characterized by the specific absorption rate (SAR) of an assembly. Maintaining a temperature in

A mid-infrared focusing grating coupler with a single circular arc element based on germanium on silicon

• Xiaojun Zhu,
• Shuai Li,
• Ang Sun,
• Yongquan Pan,
• Wen Liu,
• Yue Wu,
• Guoan Zhang and
• Yuechun Shi

Beilstein J. Nanotechnol. 2023, 14, 478–484, doi:10.3762/bjnano.14.38

• -silicon; mid-infrared; Introduction The mid-infrared (MIR) spectrum region covers the absorption band of most organic and inorganic matter. Thus, it has a broad application prospect in gas detection, environmental monitoring, lidar, free space optical communication, and remote sensing technologies [1][2

• is called “fingerprint spectrum region” (FSR) [1][4]. Many small biological molecules have unique and identifiable absorption spectra in the MIR band of 6–15 μm [1][5]. It is of great application value to develop photonic biosensors in this FSR. The spectral transparency window of germanium can fully

Mixed oxides with corundum-type structure obtained from recycling can seals as paint pigments: color stability

• Dienifer F. L. Horsth,
• Julia de O. Primo,
• Nayara Balaba,
• Fauze J. Anaissi and
• Carla Bittencourt

Beilstein J. Nanotechnol. 2023, 14, 467–477, doi:10.3762/bjnano.14.37

• ) coloration of the mixed oxides was confirmed by XPS and visible-light absorption measurements. The colorimetric stability of the oxides in acid and alkaline environments was evaluated. After 240 h of exposure to harsh environments, both pigments demonstrated stability and showed no strong color difference

• assignment is based on the intrinsic light absorption characteristics of the pigment due to the presence of a chromophore ion [8]. Different transition metals such as V, Cr, Mn, Fe, Co, Ni, and Cu have been used for this purpose [9]. Using inorganic compounds in the synthesis tends to increase the chemical

• characteristic Fe3+ satellites at higher binding energies (shifted by ca. 9 eV from Fe 2p3/2) [27], similar to that reported in [28]. Electronic spectroscopy In the UV–vis absorption spectrum of sample 1 (Figure 5a), the prominent band with a maximum centered at 588 nm can be attributed to the 4A2→4T2 transition

Conjugated photothermal materials and structure design for solar steam generation

• Chia-Yang Lin and
• Tsuyoshi Michinobu

Beilstein J. Nanotechnol. 2023, 14, 454–466, doi:10.3762/bjnano.14.36

• materials (PTMs) have attracted significant interest because of their advantages over metallic and inorganic PTMs in terms of high light absorption, designable molecular structures, flexible morphology, and solution processability. We review here the recent progress in solar steam generation devices based

• and describe commonly used conjugated organic materials and structural designs. Keywords: absorption; conjugated molecules; energy transfer; photothermal materials; solar steam generation; Review Introduction With the rapid development of the world economy, global water shortages are occurring

• efficiency in solar steam generation (SSG), three factors must be considered, namely solar light absorption, photothermal conversion efficiency, and vaporization efficiency (Figure 1). In addition, the cost of the materials must be taken into consideration as large quantities at low cost are required

Evaluation of electrosynthesized reduced graphene oxide–Ni/Fe/Co-based (oxy)hydroxide catalysts towards the oxygen evolution reaction

• Karolina Cysewska,
• Marcin Łapiński,
• Marcin Zając,
• Jakub Karczewski,
• Piotr Jasiński and
• Sebastian Molin

Beilstein J. Nanotechnol. 2023, 14, 420–433, doi:10.3762/bjnano.14.34

• probably inhibited the electrodeposition process of NiFe and CoNiFe on its surface. This may be the reason for the slower stabilization of the synthesis current density observed in the chronoamperograms (Figure 1a). X-ray diffraction, X-ray photoemission spectroscopy and X-ray absorption spectroscopy

• Figure 3a–d shows the X-ray absorption spectra (XAS) of the L3 edge of nickel (a), iron (b), cobalt (c), and carbon (d) in the studied catalysts. The appearance of a shoulder peak at the L3 edge of the nickel (Figure 3a) at 855 eV indicates the presence of oxides in the structure of the catalysts (Ni in

• absorption edges at 285.2 and 293.7 eV correspond to the excitation of electrons in the sp2 network into the π* band (C=C) and σ* band (C–C), respectively [32][33]. The signals observed at 287.2 eV (σ*: C–O and/or π*: C–OH), 288.4 eV (σ*: C–O), 290.1 eV (π*: C=O) and 291.6 eV (π*: O–C=O) correspond to a

Plasmonic nanotechnology for photothermal applications – an evaluation

• A. R. Indhu,
• L. Keerthana and
• Gnanaprakash Dharmalingam

Beilstein J. Nanotechnol. 2023, 14, 380–419, doi:10.3762/bjnano.14.33

• absorbed light to heat by these particles, has led to thriving research regarding the utilization of plasmonic nanoparticles for a myriad of applications. The design of conventional nanomaterials for PT conversion has focussed predominantly on the manipulation of photon absorption through bandgap

• engineering, doping, incorporation, and modification of suitable matrix materials. Plasmonic nanomaterials offer an alternative and attractive approach in this regard, through the flexibility in the excitation of surface plasmons. Specific advantages are the considerable improved bandwidth of the absorption

• , a higher efficiency of photon absorption, facile tuning, as well as flexibility in the synthesis of plasmonic nanomaterials. This review of plasmonic PT (PPT) research begins with a theoretical discussion on the plasmonic properties of nanoparticles by means of the quasi-static approximation, Mie

Quercetin- and caffeic acid-functionalized chitosan-capped colloidal silver nanoparticles: one-pot synthesis, characterization, and anticancer and antibacterial activities

• Akif Hakan Kurt,
• Elif Berna Olutas,
• Fatma Avcioglu,
• Hamza Karakuş,
• Mehmet Ali Sungur,
• Cansu Kara Oztabag and
• Muhammet Yıldırım

Beilstein J. Nanotechnol. 2023, 14, 362–376, doi:10.3762/bjnano.14.31

• infrared (FTIR) spectroscopy, and transmission electron microscopy (TEM). The characteristic surface plasmon resonance (SPR) absorption band has been found at 417 and 424 nm for Ch/Q- and Ch/CA-Ag NPs, respectively. The formation of a chitosan shell comprising quercetin and caffeic acid, which surround the

• nanoparticles The absorption spectra of quercetin, caffeic acid, chitosan, Ch-, Ch/Q-, and Ch/CA-Ag NPs were recorded on a UV–vis double-beam spectrophotometer (Hitachi U-2900) at wavelengths of 200 to 800 nm at 1.0 nm intervals with a quartz cell of 1.0 cm light path. Fourier-transform infrared (FTIR) spectra

• was calculated from the obtained results. Results and Discussion The characterization of the synthesized silver nanoparticles (Ag NPs) was carried out by using UV–vis absorption spectroscopy at ambient temperature. Figure 2 shows the UV–vis absorption measurement results of different Ag NPs, which are

Quasi-guided modes resulting from the band folding effect in a photonic crystal slab for enhanced interactions of matters with free-space radiations

• Kaili Sun,
• Yangjian Cai,
• Uriel Levy and
• Zhanghua Han

Beilstein J. Nanotechnol. 2023, 14, 322–328, doi:10.3762/bjnano.14.27

• the kx direction, which is the same as for the GMs. The total Q-factor (Qtotal) of a resonance observed in the far-field spectrum is determined by the Q-factors of radiation (Qrad) and absorption (Qabs) [26]: Because the absorption loss of materials is not considered here, that is, Qabs is infinite

• all GMs are infinite since we ignore the material absorption in the lossless dielectrics. When the period-doubling perturbation is applied and the new QGMs are formed because of the folding of the FBZ, the coupling efficiency between free-space radiation and the QGMs is still very low, leading to the

Bismuth-based nanostructured photocatalysts for the remediation of antibiotics and organic dyes

• Akeem Adeyemi Oladipo and
• Faisal Suleiman Mustafa

Beilstein J. Nanotechnol. 2023, 14, 291–321, doi:10.3762/bjnano.14.26

• inactivate pathogens. The term “photocatalysis” refers to chemical reactions that use light and a photocatalyst (basically a semiconductor). A few of the requirements that an effective photocatalyst system should satisfy include high sunlight absorption, an appropriate gap (1.5–2.8 eV), long-term charge

• orbitals, as opposed to the valence band of TiO2, which is made up entirely of O 2p orbitals. The mobility of the photogenerated charge carriers is increased by the well-dispersed Bi 6s orbital. Due to their distinctive structure, Bi-based photocatalysts exhibit a steeper absorption edge in the visible

• layer of the structure more quickly than those in a 3-D structure. It is important to note that an effective photocatalyst should have the following properties: (a) strong absorption both of UV and visible light (i.e., a suitable bandgap value, usually less than 3.0 eV); (b) thermal, chemical, and

Cyclodextrins as eminent constituents in nanoarchitectonics for drug delivery systems

• Makoto Komiyama

Beilstein J. Nanotechnol. 2023, 14, 218–232, doi:10.3762/bjnano.14.21

• the use of upconversion nanoparticles to convert NIR to shorter-wavelength light for photoreactions. These nanoparticles usually contain rare-earth metal ions, which have long-living excited states. Thus, they achieve sequential energy absorption and convert two or more low-energy (NIR) photons into

• , insulin was orally delivered [98]. N-Acetyl-ʟ-cysteine enhances the mucoadhesion of the drug to enhance its biological absorption, whereas arginine promotes the intestinal absorption of insulin. The composite was sufficiently water-soluble and applicable to the oral delivery of insulin, which is mostly

Concentration-dependent photothermal conversion efficiency of gold nanoparticles under near-infrared laser and broadband irradiation

• Vikas,
• Raj Kumar and
• Sanjeev Soni

Beilstein J. Nanotechnol. 2023, 14, 205–217, doi:10.3762/bjnano.14.20

• attain higher efficiencies for the nanoparticles whose absorption wavelength is different from the irradiation wavelength. Lower concentrations (1.25–5 µg/mL) of such nanoparticles show 2–3 times higher efficiency under NIR broadband irradiation. For GNRs of sizes 10 × 38 nm and 10 × 41 nm, the different

• nanoparticles shifts due to changes in the surrounding medium [14][17][26]. Thus, the same laser source may lose its suitability for applications such as photothermal therapeutics, photoacoustic imaging, and drug delivery. Also, the maximum absorption of the incident radiation is desired, which depends on the

• optical absorption characteristics of the nanoparticles. Thus, a broadband irradiation source may be useful in which the full width half maximum of the optical output can be tuned to suit the optical absorption characteristics of the nanoparticles. To the best of our knowledge, the measurement of the

Structural, optical, and bioimaging characterization of carbon quantum dots solvothermally synthesized from o-phenylenediamine

• Zoran M. Marković,
• Milica D. Budimir,
• Martin Danko,
• Dušan D. Milivojević,
• Pavel Kubat,
• Danica Z. Zmejkoski,
• Vladimir B. Pavlović,
• Marija M. Mojsin,
• Milena J. Stevanović and
• Biljana M. Todorović Marković

Beilstein J. Nanotechnol. 2023, 14, 165–174, doi:10.3762/bjnano.14.17

• toluene solution of CQDs has a strong broad absorption band at 248 nm with a shoulder at 224 nm, which represents the π–π* transition of C=C bonds. Apart from this broad band, there is a shoulder peak at 330 nm corresponding to the n–π* transition of C=O [32]. In the visible light region, at 444 nm, there

• is a weak absorption peak caused by surface state of CQDs [33][34]. Figure S2c (Supporting Information File 1) shows PL spectra of CQDs. It is obvious that the emission of CQDs does not depend on the excitation wavelength. Regardless of the excitation wavelengths the emission is located at 545 nm

• shows that the absorption of DPBF solution in both vials is nearly identical. This means that the CQDs/PU sample does not produce singlet oxygen, which confirms the previous results obtained by EPR and luminescence at 1270 nm. Ge et al. reported earlier that graphene quantum dots generate singlet oxygen

Antimicrobial and mechanical properties of functionalized textile by nanoarchitectured photoinduced Ag@polymer coating

• Jessica Plé,
• Marine Dabert,
• Helene Lecoq,
• Sophie Hellé,
• Lydie Ploux and
• Lavinia Balan

Beilstein J. Nanotechnol. 2023, 14, 95–109, doi:10.3762/bjnano.14.11

• increases with exposure time, which indicates an increase in NP concentration. Since the absorption peak is 426 nm for the Ag@PEG600DA/PETIA coating, the particles are expected to be slightly smaller than those of the Ag@PEG600DA film. This can be explained by the fact that the PETIA comonomer is a

• reflectance, mainly diffuse. The underlying metallic layer appears brown and exhibits an absorption band at 430 nm, linked to the plasmon resonance of AgNPs (Figure 8c), trapped inside the polymer matrix. To better understand this sudden decrease in reflectance, the surface was characterized by SEM (Figure 8c

Combining physical vapor deposition structuration with dealloying for the creation of a highly efficient SERS platform

• Adrien Chauvin,
• Walter Puglisi,
• Damien Thiry,
• Cristina Satriano,
• Rony Snyders and
• Carla Bittencourt

Beilstein J. Nanotechnol. 2023, 14, 83–94, doi:10.3762/bjnano.14.10

• adsorption isotherm curve of RhB [49][50]. The plateau in the SERS response observed between 10−8 and 10−10 mol·L−1 can be assigned to either the saturation of the chemical sites (i.e., no supplementary absorption is made) or to the fact that RhB continued to be absorbed outside of the hot spot [6][51

Frontiers of nanoelectronics: intrinsic Josephson effect and prospects of superconducting spintronics

• Anatolie S. Sidorenko,
• Horst Hahn and
• Vladimir Krasnov

Beilstein J. Nanotechnol. 2023, 14, 79–82, doi:10.3762/bjnano.14.9

• frequency range, switching from the superconducting to the resistive state due to absorption of a 10 GHz external signal [19]. Achieving a large coherent gain of the receiver, up to a factor of three, of the emitted power from two simultaneously biased arrays of Josephson junctions compared to that of the

Two-step single-reactor synthesis of oleic acid- or undecylenic acid-stabilized magnetic nanoparticles by thermal decomposition

• Mykhailo Nahorniak,
• Pamela Pasetto,
• Jean-Marc Greneche,
• Volodymyr Samaryk,
• Sandy Auguste,
• Anthony Rousseau,
• Nataliya Nosova and
• Serhii Varvarenko

Beilstein J. Nanotechnol. 2023, 14, 11–22, doi:10.3762/bjnano.14.2

• visible at 1577 and 1524 cm−1 and a band at 432 cm−1 corresponds to the vibrations of Fe–O or С–СН3 [29][30]. At the end of the first stage (SFin Stage1), the absorption bands corresponding to the acetylacetonate ligand or acetylacetone residues are not observed. The absorption band at 432 cm−1 also

• SFin Stage1, Figure S2 and Figure S3 in Supporting Information File 1) formed due to the exchange reaction of acetylacetonate and a higher acid show several absorption bands which were absent in the spectra of reactants and 1-octadecene (Table 2). The low-intensity absorption band at 1741–1742 cm−1

• , which appeared in the spectra of the reaction mixture of both oleate and undecylate complexes in octadecene, corresponds to vibrations of the carbonyl group of free unassociated acid. This band is not observed in the spectra of pure acids. The absorption band at 1711 cm−1 in both cases can be attributed