Photothermal Superhydrophobic Chitosan-Based Cotton Fabric for Rapid Deicing and Oil/Water Separation.

Superhydrophobic cotton fabrics have a lot of potential for use in practical settings. The majority of superhydrophobic cotton fabrics, however, only serve one purpose and are made from fluoride or silane chemicals. Therefore, it remains a challenge to develop multifunctional superhydrophobic cotton fabrics using environmentally friendly raw materials. In this study, chitosan (CS), amino carbon nanotubes (ACNTs), and octadecylamine (ODA) were used as raw materials to create CS-ACNTs-ODA photothermal superhydrophobic cotton fabrics. The cotton fabric that was created showed a remarkable superhydrophobic property with a water contact angle of 160.3°. The surface temperature of CS-ACNTs-ODA cotton fabric can rise by up to 70 °C when exposed to simulated sunlight, demonstrating the fabric's remarkable photothermal capabilities. Additionally, the coated cotton fabric is capable of quick deicing. Ice particles (10 µL) melted and began to roll down in 180 s under the light of "1 sun". The cotton fabric exhibits good durability and adaptability in terms of mechanical qualities and washing tests. Moreover, the CS-ACNTs-ODA cotton fabric displays a separation efficacy of more than 91% when used to treat various oil and water mixtures. We also impregnate the coating on polyurethane sponges, which can quickly absorb and separate oil and water mixtures.

Spectroscopic Identification of the Dinitrogen Fixation and Activation by Metal Carbide Cluster Anions PtCn- (n = 4-6).

Nitrogen fixation is confronted with great challenges in the field of chemistry. Herein, we report that single metal carbides PtCn- and PtCnN2- (n = 4-6) are indispensable intermediates in the process of nitrogen fixation by mass spectrometry coupled with anionic photoelectron spectroscopy, quantum chemical calculations, and simulated density-of-state spectra. The most stable isomers of these cluster anions are characterized to have linear chain structures. The fixation and activation of dinitrogen are facilitated by the charge transfer from Pt and Cn to N2. The significance of π back-donation of the 5d orbital of the Pt atom to the antibonding π orbits of N2 for dinitrogen fixation and activation is discussed in detail. This study not only provides a theoretical basis at the molecular level for the activation of dinitrogen by mononuclear metal carbide clusters but also provides a new paradigm for dinitrogen fixation.

Iridium Dimer Anion-Mediated C≡C Triple Bond Cleavage and Successive Dehydrogenation of Acetylene in the Gas Phase.

The reactions of the iridium dimer anion [Ir2]- with acetylene have been studied by mass spectrometry in the gas phase, which indicate that the [Ir2]- anion can consecutively react with C2H2 molecules to form the [Ir2C2x]- (x = 1, 2) and [Ir2C2yH2]- (y = 3-5) anions as major products with the successive release of H2 molecules at room temperature. The reactions are confirmed by the reactions of the mass-selected product [Ir2C2]- anion with C2H2 to produce [Ir2C4]- and [Ir2C2yH2]- (y = 3-5). Photoelectron spectra and quantum chemistry calculations confirm that the [Ir2C2x]- (x = 1, 2) product anions possess cyclic [Ir(µ-C)2Ir]- and [Ir(µ-C)(µ-C3)Ir]- structures, implying that the robust C≡C triple bond of acetylene can be completely cleaved by the [Ir2]- anion.

Observation of unsaturated platinum carbenes Pt2C2n - (n = 1-3) clusters: A photoelectron imaging spectroscopic and theoretical study.

The structural and bonding properties of the Pt2C2n - (n = 1-3) complexes have been investigated by mass-selected photoelectron velocity-map imaging spectroscopy with quantum chemical calculations. The adiabatic detachment energies and vertical detachment energies of Pt2C2n - have been obtained from the measured photoelectron imaging spectra. Theoretical results indicate that the lowest-energy isomers of Pt2C2n - (n = 1-3) possess linear chain-shaped configurations. The binding motif in the most stable isomer of Pt2C2 - has a linear cumulenic structure with a Pt=C=C=Pt configuration, and the structural characteristic persists up to all the lowest-energy isomers of the Pt2C4 - and Pt2C6 - anions. The chemical bonding analyses indicate that the Pt2C2n - (n = 1-3) complexes have multicenter two-electron characteristics.

Suppression of PAPP-A mitigates atherosclerosis by mediating macrophage polarization via STAT3 signaling.

Pregnancy-associated plasma protein-A (PAPP-A), a type of metalloproteinase in the insulin-like growth factor (IGF) system, has been implicated in atherosclerosis progression, but its function and mechanism in atherosclerosis is not fully understood. The study was performed to further explore the effects of PAPP-A on inflammation, macrophage polarization and atherosclerosis. In mouse macrophages stimulated by oxidized low-density lipoprotein (ox-LDL), PAPP-A expression was significantly increased. Its knockdown markedly mitigated inflammatory response and polarized macrophages to an M2-like phenotype in RAW264.7 cells upon ox-LDL treatment. Additionally, ox-LDL-induced activation of nuclear factor-κB (NF-κB) signaling pathway was dramatically restricted by PAPP-A knockdown in macrophages. However, JAK2/STAT3 activation was significantly up-regulated in RAW264.7 cells with PAPP-A inhibition after ox-LDL treatment. Importantly, we found that PAPP-A knockdown-induced polarization of M2-like phenotype in macrophages was mainly dependent on STAT3 activation. Clinical studies showed that serum PAPP-A levels were higher in patients with coronary artery disease (CAD) than that of healthy individuals. Apolipoprotein E-knockout (ApoE-/-) mice with high fat diet (HFD)-induced atherosclerosis exhibited higher expression of PAPP-A in aortas, which was mainly colocalized with F4/80. Subsequently, we found that PAPP-A deficiency greatly alleviated plaque formation, lesion burden and collagen accumulation in HFD-fed ApoE-/- mice. Consistent with in vitro macrophage phenotype, PAPP-A-/- reduced F4/80 expression, NF-κB activation and inflammatory response, while improved janus kinase 2/signal transducer and activator of transcription 3 (JAK2/STAT3) signaling and polarized macrophages to an M2-like phenotype in aortas of ApoE-/- mice after HFD feeding. In conclusion, these findings identified PAPP-A as a positive regulator of atherosclerosis by regulating macrophage polarization via STAT3 signal, and thus could be considered as a potential therapeutic target for atherosclerosis treatment.

MicroRNA-221 Upregulates the Expression of P-gp and Bcl-2 by Activating the Stat3 Pathway to Promote Doxorubicin Resistance in Osteosarcoma Cells.

MicroRNA-221 (miRNA-221) is upregulated in several malignant tumors and is associated with poor patient prognosis. Therefore, the present study aimed to investigate the role and underlying mechanism of miRNA-221 in doxorubicin (DOX) resistance in osteosarcoma cells. We constructed DOX-resistant Saos-2/DOX cells and treated them with DOX. Cell viability was determined by performing a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Cells were transfected with either miRNA-221 mimic or miRNA-221 inhibitor; quantitative (q)RT-PCR was performed to detect the expression of miRNA-221. Flow cytometry and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-digoxigenin nick-end labeling (TUNEL) staining were used to detect cell apoptosis. The immunofluorescence method was also used to detect cell signal transduction and activator of transcription 3 (Stat3) protein expression distribution. In addition, Western blotting was used to detect changes in the expression of each protein. We found that miRNA-221 was upregulated in Saos-2/DOX cells. Moreover, the miRNA-221 mimic induced DOX resistance in Saos-2 cells, whereas the miRNA-221 inhibitor enhanced DOX sensitivity in Saos-2/DOX cells. The miRNA-221 mimic upregulated the expression of phosphorylated-Stat3, P-glycoprotein (P-gp), and B-cell lymphoma-2 (Bcl-2) proteins in Saos-2 cells and induced the entry of Stat3 into the nucleus, whereas the miRNA-221 inhibitor exerted the opposite effect. Pretreatment with the Stat3 chemical inhibitor, STAT3-IN-3, significantly inhibited the upregulation of P-gp and Bcl-2 protein expression induced by the miRNA-221 mimic in Saos-2 cells; it also caused the Saos-2 cells to overcome DOX resistance induced by the miRNA-221 mimic. Thus, miRNA-221 increased the expression of P-gp and Bcl-2 by activating the Stat3 pathway to promote DOX resistance in osteosarcoma cells, indicating a potential use of miRNA-221 in osteosarcoma treatment.

Dance intervention effects on physical function in healthy older adults: a systematic review and meta-analysis.

BACKGROUND AND OBJECTIVE: Dancing is a form of physical exercise associated with health benefits in older adults. Regular dancing can prolong healthy aging, maintain or even improve physical function, and thus enhance their quality of life. The aim of this review was to evaluate the effects of dance intervention on physical function performance in healthy older adults in randomized-controlled trials (RCTs). METHODS: Five electronic databases (Cochrane Library, PsycINFO, PubMed, Scopus, and Web of Science) were searched systematically until the end of June 2018 by two independent reviewers. These searches were limited to the English language and persons with average age older than 65. The tool from the Cochrane Collaboration was used to assess the risk of bias. A standard meta-analysis was performed using Review Manager Software version 5.3. RESULTS: Thirteen RCTs from a total of 1029 older participants were included in this meta-analysis. The results showed that dance intervention significantly improved mobility function and endurance performance when compared with control groups for healthy older adults. However, gait was not significantly improved through dancing. Studies included in this review were not enough to perform meta-analysis for the effectiveness of dance on balance and general health in healthy older adults. CONCLUSION: Overall, dance intervention was effective to improve physical function performance in healthy older adults. The results from this meta-analysis strengthen the evidence from previous individual studies. Properly organized dance intervention would be a safe and effective exercise to incorporate into daily life.

Coronary Artery-Left Ventricular Fistula with Giant Right Coronary Aneurysm: A Case Report and Literature Review.

Right coronary artery-left ventricular (RCA-LV) fistula with associated giant right coronary artery aneurysm (CAA) is an extremely rare cardiac condition. This case study presents a patient with a large left ventricle (LV) and a giant right CAA with a maximal inner diameter of approximately 56.6 mm and an inner diameter of approximately 22 mm at its communication with the left ventricle. The patient underwent surgical management, involving suturing of the proximal end of the CAA and coronary artery bypass grafting (CABG). RCA-LV fistula with a giant right CAA may involve serious complications, such as thrombosis, rupture, and heart failure. Therefore, it is necessary to establish effective management strategies for this condition. Although this case is not unique, it serves as an illustrative example of the implementation of a classic surgical treatment method.

Microplasma Anode Meeting Molten Salt Electrochemistry: Charge Transfer and Atomic Emission Spectral Analysis.

Molten salt electrolysis is normally conducted with solid anode, such as noble metal or graphite, which has defects such as high cost or emission of carbon oxide. Herein, we report that a microplasma based on atmospheric-pressure glow discharge could act as a kind of gaseous anode for electrolysis in molten salt. When the Ag/Ag+ redox couple was chosen as the research object, the microplasma anode could initiate charge-transfer reactions in the molten salt and Ag could be electrodeposited with current efficiency of above 90%. The microplasma anode has also shown excellent anticorrosive performance in both chloride and carbonate molten salt. Furthermore, the microplasma anode could potentially serve as an excitation source of atomic emission spectrometry (AES), making it possible to determine the concentration of Ag ions in the molten salt in situ and in real-time. With properties such as being carbon-free and having corrosion resistance and extensive utilization for analysis, the microplasma anode has opened a new direction for molten salt electrochemistry.

Histone deacetylase inhibitor SAHA-induced epithelial-mesenchymal transition by upregulating Slug in lung cancer cells.

SAHA, a member of histone deacetylase inhibitors (HDACIs), which emerged as a class of novel antitumor drug, has been used in clinical treatment of cancers. However, clinical experience of SAHA in solid tumors has been disappointing. Nevertheless, the underlying mechanism of this deficiency is not clearly understood. In the present study, we found that SAHA could induce epithelial-mesenchymal transitions (EMT) in lung cancer A549 cells, which was associated with increased migration capability and cellular morphology changes. We showed that SAHA decreased epithelial marker E-cadherin's expression and increased the expression of mesenchymal marker vimentin. SAHA upregulated the protein and mRNA expression of transcription factor Slug in a time-dependent manner and promoted its nuclear translocation. We further demonstrated that SAHA upregulated Slug expression by promoting Slug acetylation but not influencing the phosphorylation of GSK-3ß, a main kinase-controlled Slug expression. Finally, silencing of Slug by siRNA reversed EMT marker expressions and cellular morphology change induced by SAHA, suggesting that Slug plays a crucial role in SAHA-mediated EMT in A549 cells. Our research study provided a better understanding of treatment failure of SAHA in patients with solid tumors. Therefore, more attention should be paid to cancer treatment using SAHA and strategies for reversing EMT before using SAHA would be better if the value of SAHA in the treatment of solid tumors, especially lung cancer, is realized.

Dinitrogen Activation by Heteronuclear Bimetallic Cluster Anion FeV- in the Gas Phase.

Nitrogen activation is a significant but difficult project in the chemical area. Photoelectron spectroscopy (PES) and calculated results are used to investigate the reaction mechanism of the heteronuclear bimetallic cluster FeV- toward N2 activation. The results clearly show that N2 can be fully activated by FeV- at room temperature, forming the FeV(µ2-N)2- complex with the totally ruptured N≡N bond. Electronic structure analysis reveals that the activation of N2 by FeV- is achieved by the electron transfer of bimetallic atoms and electron back-donation to the metal core, which demonstrates that heteronuclear bimetallic anionic clusters are very important to nitrogen activation. This study provides important information for the rational design of synthetic ammonia catalysts.

Novel Life Prediction Method of PMMA for Cultural Relics Protection Based on the BP Neural Network.

Poly(methyl methacrylate) (PMMA) is widely used in the preservation and exhibition of cultural relics in museums. Accurately predicting its service life can help avoid many negative effects caused by PMMA aging. To study the change in the yellowing index of PMMA after aging in a UV light environment, an aging experiment was conducted. A prediction model for the service life of PMMA was established using nonlinear curve fitting and a back propagation (BP) neural network. By comparing the goodness of fit, simulation and modeling capabilities of the initial data, and the predictive ability for new data, it was found that the BP neural network prediction model outperformed the nonlinear curve fitting prediction model. In this study, the service life of newly produced PMMA samples was calculated as 7.83, 8.47, and 8.42 years, based on the yellowing index of retired PMMA as a benchmark and using the output data from the BP neural network prediction model. At this time, the performance and exhibition effect of the PMMA are poor, and the batch of PMMA needs to be updated.

Comparison of clinical outcomes of using the nonirradiated and irradiated allograft for anterior cruciate ligament (ACL) reconstruction: A systematic review update and meta-analysis.

BACKGROUND: This study was a systematic review comparing the clinical outcomes of using the nonirradiated and irradiated allograft for anterior cruciate ligament (ACL) reconstruction. METHODS: A comprehensive literature search was conducted using multiple databases, including Medline, Embase, and Cochrane. All databases were searched from the earliest records through August 2019 using the following Boolean operators: irradiated AND nonirradiated AND ACL AND allograft. All prospective and retrospective controlled trials were retrieved that directly compared physical examination and knee function scores and patient-rated outcomes between the nonirradiated and irradiated allograft for ACL reconstruction. RESULTS: Three prospective and 2 retrospective articles were identified by the search, and the findings suggested that the nonirradiated allografts were superior to the irradiated allografts based on improved knee joint functional scores and decreased failure rate, even though there was no significantly difference with respect to overall IKDC, range of motion, vertical jump test, and one-leg hop test. CONCLUSIONS: Irradiated allograft should be limited to be used in ACL surgery and further research into new alternative sterilization techniques are needed to avoiding the disease transmission without interference with the biomechanical properties of the grafts.

Isoelectronic IrC3-, PtC3, and AuC3+ Clusters Featuring the Structural and Bonding Resemblance to OC3.

The IrC3- and PtC3- anions generated by laser vaporization were identified and characterized by gas-phase photoelectron spectroscopy and quantum-chemical calculations. The straight-chain structures with an MCCC (M = metal; C = carbon) connectivity are found for the isoelectronic IrC3-, PtC3, and AuC3+ clusters. Further elaborate analyses manifest the strikingly structural and bonding similarities between MC3-/0/+ clusters and OC3 revealed. This finding has broadened the notion of autogenic isolobality to the gas-phase clusters that contain Ir-, Pt, Au+, and C centers.

Evaluating the Effect of Circ-Sirt1 on the Expression of SIRT1 and Its Role in Pathology of Pulmonary Hypertension.

Pulmonary arterial hypertension (PAH) is a disease that plagues a major portion of the world's population, and there is currently no effective cure for this ailment. The proliferation and migration of pulmonary artery smooth muscle cells (PASMC) are known to be the pathological basis of pulmonary vascular remodeling in pulmonary hypertension. Studies in the past have shown involvement of CircRNA in the pathology of pulmonary as well as cardiovascular diseases. However, there are very few studies that have analyzed the relationship between CircRNA and PAH. The aim of this study was to explore this relationship by using rat PAH model. A hypoxic, PAH rat model was constructed for this study and the subsequently produced hypoxia-induced rat PASMC cells were utilized to demonstrate the reduction in expression of circular RNA of Silent information regulator factor 2-related enzyme 1 (circ-Sirt1) and SIRT1 mRNA in response to hypoxia, through cell function tests, cell rescue tests, and physical tests. We found that the expression of circ-Sirt1 and SIRT1 decreased in the PAH rat model induced by hypoxia. It was also revealed that the overexpression of circ-SIRT1 increased SIRT1 levels, but inhibited the expression of transforming growth factor (TGF)-ß1, Smad3, and Smad7, and weakened PASMC cell vitality, proliferation, and migration ability. The findings of the present study indicate that circ-Sirt1 regulates the expression of SIRT1 mRNA and inhibits TGF-ß1/Smad3/Smad7 mediated proliferation and migration of PASMC. This provides a new insight into the molecular mechanism of pulmonary artery vascular remodeling in PAH and may aid in the development of novel therapeutic options for management of PAH.

[Establishment of a porcine model of congenital heart defect with decreased pulmonary blood flow].

OBJECTIVE: To establish an animal model of congenital heart defect with decreased pulmonary blood flow for better understanding the pathophysiology of pulmonary vascular development and related regulatory mechanisms of congenital heart defect with decreased pulmonary blood flow. METHOD: One to two months old pigs were randomly divided into three groups: control group (group C, n = 6) with right chest small incisions induced transient pulmonary blood reduction; light-moderate stenosis groups (group T(1), n = 7): artificial atrial septum defect (ASD) plus controlled pulmonary artery banding to generate a systolic pressure gradient of 20 - 30 mm Hg (1 mm Hg = 0.133 kPa); severe stenosis groups (group T(2), n = 7): similar surgical procedures as group T(1), and controlled pulmonary artery banding to generate a systolic pressure gradient ≥ 30 - 50 mm Hg. 64-slice computed tomography scanning was performed at one month post operation. Arterial blood gas analysis, hemoglobin value, pulmonary vessel, ASD and banding ring diameters and trans-pulmonary artery banding pressure (Trans-PABP) were determined at two months post operation. RESULTS: One pig died due to tracheal intubation accident in the C group, one pig died due to bowel obstruction in the T(1) group and two pigs died due to acute right heart failure and chronic heart failure respectively in T(2) group. 64-slice CT angiography results showed that aortic diameter of T(1) group was significantly lower than that of C group and banding diameter was significantly lower than aortic diameter in the T(1) and T(2) groups at one month post operation. Two months after operation, the size of ASD were (8.0 ± 0.5) mm and (8.9 ± 1.4) mm (P > 0.05) respectively in the T(1) and T(2) groups after operation. The Trans-PABP was significantly higher in the T(1) and T(2) groups than in C group (P < 0.01), and the Trans-PABP was significantly higher in the T(2) group than in T(1) group (P < 0.01). PaO2 and SaO2 in the T(1) and T(2) groups were significantly lower than those in C group. CONCLUSION: Artificial atrial septum defect combined pulmonary artery banding procedures could be successfully used to establish model of congenital heart defect with decreased pulmonary blood flow and this model could help to understand the pathophysiology and monitor therapy efficacy for patients with congenital heart defect with decreased pulmonary blood flow.

[Establishment of a cyanotic congenital heart defect porcine model with decreased pulmonary blood flow].

OBJECTIVE: To establish a porcine model of congenital heart disease with decreased pulmonary blood to explore the morphological changes of immature pulmonary vascular vessels. METHODS: Twenty piglets (one to two-month-old) were randomly divided into three groups: sham-operated group (group S, n = 6), small incisions on the right chest, produced a transient reduction in pulmonary blood; Operation group 1(group T(1), n = 7), small incisions on the right chest, producing artificial atrial defect with self-made dilator and simultaneous banding pulmonary artery to generate a systolic pressure gradient between 20 - 30 mm Hg (1 m Hg = 0.133 kPa); Operation group 2(group T(2), n = 7): operation procedure was similar as group T(1) with systolic pressure gradient between 30 - 50 mm Hg. Lung tissue from right middle lobe (1.0 cm×0.8 cm×0.8 cm) was taken immediately after thoracotomy, at the end of surgery and at 2 months after operation and stained by Weigert (elastic fiber) and van Gieson (collagen) methods to observe the morphological changes. RESULTS: Five animals survived in Group S, 6 animals survived in group T(1) and 5 animals survived in group T(2). The inside diameter of pulmonary arterioles after thoracotomy and at the end of surgery was similar among the three groups (P > 0.05). At 2 months after operation, the inside diameter of pulmonary artery was significantly higher in group T(1) and T(2) than in group S (all P < 0.05) while the number of pulmonary small artery per square centimeter (APSC) of group T(1) and T(2) was significantly lower than that of group S (all P < 0.05). Tunica media of pulmonary artery was thinner and vascular lumen was larger in group T(1) and T(2) compared to those of group S. CONCLUSION: In this piglets model with reduced pulmonary blood, the pulmonary arterioles underwent dysplastic changes. Thus, pulmonary blood flow is an important determinant for the physiological development of pulmonary artery.

The diagnosis and treatment of cardiac lymphangioma: A case report and literature review.

RATIONALE: Cardiac lymphangioma is a rare disease. Until now, there have been only a few cases of cardiac lymphangioma reported in the literature. PATIENT CONCERNS: We report the case of a 57-year-old female patient with cardiac lymphangioma from atrial septum. DIAGNOSIS: Color Doppler echocardiography was performed, which revealed a tumor occupying a large amount of space in the left and right atrium. INTERVENTIONS: The patient underwent thoracoscopic cardiac tumor resection under general anesthesia according to the procedure used for benign tumors. OUTCOMES: The patient recovered completely and was discharged home. Follow-up color Doppler echocardiography scans obtained from 6 months to 2 years after the operation showed no recurrent mass. LESSONS: Once the tumor is detected, surgical treatment should be implemented as soon as possible.

APPBP2 enhances non-small cell lung cancer proliferation and invasiveness through regulating PPM1D and SPOP.

BACKGROUND: The influence of amyloid protein-binding protein 2 (APPBP2) on lung cancer is unknown. METHODS: The function and mechanisms of APPBP2 were investigated in the NSCLC cell lines A549 and H1299. The ectopic expression of APPBP2, PPM1D and SPOP in NSCLS were examined in samples collected from ten pairs of human lung adenocarcinoma cancer tissues and adjacent normal lung tissues. shRNA vector was used for APPBP2 knockdown. Quantitative PCR and western blot assays quantified the mRNA and protein level of APPBP2, PPM1D, and SPOP. Cell proliferation was measured with BrdU, MTT, colony formation assays, and xenograft tumour growth experiments. Cell migration and invasion were analysed with transwell and wound healing assays. Co-Immunoprecipitation assay detected protein-protein interactions. FINDINGS: APPBP2 was upregulated in NSCLC tissues. Silencing APPBP2 in A549 and H1299 cells resulted in the inhibition of cell proliferation, migration, and invasion, enhancement of apoptosis, and a significant decrease in the expression of PPM1D and SPOP. Overexpression of PPM1D and SPOP attenuated the APPBP2-knockdown inhibition of NSCLC cells. Co-IP assay showed that PPM1D interacted with APPBP2. INTERPRETATION: The expression level of APPBP2 positively correlates with NSCLC cell proliferation, migration, and invasiveness. APPBP2 contributes to NSCLC progression through regulating the PPM1D and SPOP signalling pathway. This novel molecular mechanism, underlying NSCLC oncogenesis, suggests APPBP2 is a potential target for diagnosis and therapeutic intervention in NSCLC. FUND: Key Program of Natural Science Research of Higher Education of Anhui Province (No. KJ2017A241), the National Natural Science Foundation of China (No. 81772493).

Quantum Chemistry Study on the Extraction of Trivalent Lanthanide Series by Cyanex301: Insights from Formation of Inner- and Outer-Sphere Complexes.

The extraction of lanthanide series by Cyanex301, i.e., bis(2,4,4-trimethylpentyl)dithiophosphinic acid (HC301), has been modeled by density functional theory calculation, taking into account the formation of both inner- and outer-sphere complexes. The inner-sphere complex Ln(C301)3 and the outer-sphere complex Ln(H2O)9(C301)3 are optimized, followed by the analysis of interaction energy, bond length, Laplacian bond orders, and Mulliken populations. The covalency degree increases in Ln-S and Ln-O bonds in the inner- and outer-sphere complexes, respectively, as the lanthanide series is traversed. Mulliken population analysis indicates the important role of the 5d-orbital participation in bonding in the formation of inner- and outer-sphere complexes. Two thermodynamic cycles regarding the formation of inner- and outer-sphere complexes are established to calculate the extraction Gibbs free energies (ΔG extr), and relaxed potential energy surface scan is utilized to model the kinetic complexation of C301 anion with hydrated metal ions. Light lanthanides can form both inner- and outer-sphere complexes, whereas heavy lanthanides only form outer-sphere complexes in biphasic extraction. After adopting the data of forming inner-sphere complex for light Ln(III) and that of forming outer-sphere complexes for heavy Ln(III), the trend of the calculated -ΔG extr agrees very well with that of the experimental distribution ratios on crossing the Ln(III) series. Results from this work help to theoretically understand the extraction behavior of Cyanex301 with respect to different Ln(III).