Chemistry Commons^™

Probing Radical Pathways In Electrophilic Addition Of Halogens: Classical Vs. Bridged Intermediates, Lisa George, Aimable Kalume, Scott Reid

Chemistry Faculty Research and Publications

We examine radical mediated pathways in electrophilic addition to the simplest alkene, ethylene, where the structure of the radical intermediate has been extensively debated. Starting from the π-complex with a dihalogen, C₂H₄⋯I₂, isolated in an inert matrix, we initiate reaction by photolytically cleaving the I₂ bond. We succeed in trapping and spectroscopically interrogating the symmetrically bridged radical complex, which calculations confirm is the global minimum on the C₂H₅I Potential Energy Surface (PES). Consistent with the participation of a bridged intermediate, radical addition preferentially but not exclusively yields the anti …

On Pi-Stacking, Ch/Pi, And Halogen Bonding In Halobenzene Clusters: Resonant 2-Photon Ionization Studies Of Chlorobenzene, Lloyd Muzangwa, Silver Nyambo, Brandon Uhler, Scott Reid

Chemistry Faculty Research and Publications

Noncovalent interactions such as hydrogen bonding, π-π stacking, CH/π interactions, and halogen bonding play crucial roles in a broad spectrum of chemical and biochemical processes, and can exist in cooperation or competition. Here we report studies of the homoclusters of chlorobenzene, a prototypical system where π-π stacking, CH/π interactions, and halogen bonding interactions may all be present. The electronic spectra of chlorobenzene monomer and clusters (Clbz)_n with n = 1-4 were obtained using resonant 2-photon ionization in the origin region of the S₀–S₁ (ππ*) state of the monomer. The cluster spectra show in all cases a …

On The Electronic Spectroscopy Of The Iso-Polyhalomethanes, Aimable Kalume, Lisa George, Scott Reid

Chemistry Faculty Research and Publications

The iso-polyhalomethanes are important reactive intermediates, displaying intense near-UV absorption bands that have been assigned to the S₀ → S₃ transition on the basis of Time-Dependent Density Functional Theory (TDDFT) calculations. In this work, theory and multi-dimensional Franck–Condon (FC) analysis are used to model the electronic spectra of selected iso-polyhalomethanes. The S₀ → S₃ transition approximately corresponds to a π–π^∗ transition on the halocarbocation subunit, which induces significant geometry changes. The calculated multimode FC profiles capture features of the experimental spectra of the matrix-isolated species, and are compared with the results of previous Resonance Raman …

Electronic Communication Across Diamagnetic Metal Bridges: A Homoleptic Gallium(Iii) Complex Of A Redox-Active Diarylamido-Based Ligand And Its Oxidized Derivatives, Brendan J Liddle, Sarath Wanniarachchi, Jeewantha S. Hewage, Sergey Lindeman, Brian Bennett, James R. Gardinier

Chemistry Faculty Research and Publications

Complexes with cations of the type [Ga(L)₂]ⁿ⁺ where L = bis(4-methyl-2-(1H-pyrazol-1-yl)phenyl)amido and n = 1, 2, 3 have been prepared and structurally characterized. The electronic properties of each were probed by electrochemical and spectroscopic means and were interpreted with the aid of density functional theory (DFT) calculations. The dication, best described as [Ga(L^–)(L⁰)]²⁺, is a Robin-Day class II mixed-valence species. As such, a broad, weak, solvent-dependent intervalence charge transfer (IVCT) band was found in the NIR spectrum in the range 6390–6925 cm^–1, depending on the solvent. Band shape …

Spectroscopic And Computational Studies Of Matrix-Isolated Iso-Cxbr3 (X=F,Cl,Br): Structure, Properties, And Photochemistry Of Substituted Iso-Tribromomethanes, Lisa George, Aimable Kalume, Scott Reid, Brian J. Esselman, Robert J. Mcmahon

Chemistry Faculty Research and Publications

Iso-polyhalomethanes are important reactive intermediates in the condensed and gas-phase chemistry of halomethanes. Building upon our recent study of iso-bromoform, in this work the substituted iso-tribromomethanes (iso-CXBr₃; X = F, Cl, Br) were characterized by matrix isolation infrared and UV/Vis spectroscopy, supported by ab initio calculations, to further probe the structure, spectroscopy, properties, and photochemistry of these important intermediates. Selected wavelength laser irradiation of CXBr₃ samples in an inert rare gas (typically Ar; mixing ratio 1:500) held at ∼5 K yielded iso-CXBr₃ (XBrC–Br–Br or Br₂C–Br–X). The observed infrared and UV/Vis absorptions are in excellent …

Chemical Proteomics-Based Analysis Of Off-Target Binding Profiles For Rosiglitazone And Pioglitazone: Clues For Assessing Potential For Cardiotoxicity, Brian R. Hoffmann, Mohamed F. El-Mansy, Daniel S. Sem, Andrew S. Greene

Chemistry Faculty Research and Publications

Drugs exert desired and undesired effects based on their binding interactions with protein target(s) and off-target(s), providing evidence for drug efficacy and toxicity. Pioglitazone and rosiglitazone possess a common functional core, glitazone, which is considered a privileged scaffold upon which to build a drug selective for a given target—in this case, PPARγ. Herein, we report a retrospective analysis of two variants of the glitazone scaffold, pioglitazone and rosiglitazone, in an effort to identify off-target binding events in the rat heart to explain recently reported cardiovascular risk associated with these drugs. Our results suggest that glitazone has affinity for dehydrogenases, consistent …

Experimental Documentation Of The Structural Consequences Of Hydrogen-Bonding Interactions To The Proximal Cysteine Of A Cytochrome P450, Piotr J. Mak, Yuting Yang, Sangchoul Im, Lucy A. Waskell, James R. Kincaid

Chemistry Faculty Research and Publications

Resonance Raman spectroscopy is used to document, for the first time, a 6 cm−1 decrease of the Fe-S stretch by introducing an H-bond donor into the proximal pocket of a cytochrome P450, which interacts with the key cysteine thiolate axial ligand. The anticipated trans-effect on bound exogenous ligands is also confirmed and evidence is obtained supporting intimate interaction of the new histidyl-imidazole fragment with the heme periphery.

Syntheses And Electronic Properties Of Rhodium(Iii) Complexes Bearing A Redox-Active Ligand, Sarath Wanniarachchi, Brendan J Liddle, Brandon Kizer, Jeewantha S. Hewage, Sergey Lindeman, James R. Gardinier

Chemistry Faculty Research and Publications

A series of rhodium(III) complexes of the redox-active ligand, H(L = bis(4-methyl-2-(1H-pyrazol-1-yl)phenyl)amido), was prepared, and the electronic properties were studied. Thus, heating an ethanol solution of commercial RhCl3·3H2O with H(L) results in the precipitation of insoluble [H(L)]RhCl3, 1. The reaction of a methanol suspension of [H(L)]RhCl3 with NEt4OH causes ligand deprotonation and affords nearly quantitative yields of the soluble, deep-green, title compound (NEt4)[(L)RhCl3]·H2O, 2·H2O. Complex 2·H2O reacts readily with excess pyridine, triethylphosphine, or pyrazine (pyz) to eliminate NEt4Cl and give charge-neutral complexes trans-(L)RhCl2(py), trans-3, trans-(L)RhCl2(PEt3), trans- 4, or trans-(L)RhCl2(pyz), trans-5, where the incoming Lewis base is trans- to the amido …

Structural, Spectroscopic, And Electrochemical Properties Of Nonheme Fe(Ii)-Hydroquinonate Complexes: Synthetic Models Of Hydroquinone Dioxygenases, Amanda E. Baum, Heaweon Park, Denan Wang, Sergey Lindeman, Adam T. Fiedler

Chemistry Faculty Research and Publications

Using the tris(3,5-diphenylpyrazol-1-yl)borate (^Ph2Tp) supporting ligand, a series of mono- and dinuclear ferrous complexes containing hydroquinonate (HQate) ligands have been prepared and structurally characterized with X-ray crystallography. The monoiron(II) complexes serve as faithful mimics of the substrate-bound form of hydroquinone dioxygenases (HQDOs) – a family of nonheme Fe enzymes that catalyze the oxidative cleavage of 1,4-dihydroxybenzene units. Reflecting the variety of HQDO substrates, the synthetic complexes feature both mono- and bidentate HQate ligands. The bidentate HQates cleanly provide five-coordinate, high-spin Fe(II) complexes with the general formula [Fe(^Ph2Tp)(HL^X)] (1X), where HL^X is …

Fe(Ii) Complexes That Mimic The Active Site Structure Of Acetylacetone Dioxygenase: O2 And No Reactivity, Heoweon Park, Michael M. Bittner, Jacob Baus, Sergey Lindeman, Adam T. Fiedler

Chemistry Faculty Research and Publications

Acetylacetone dioxygenase (Dke1) is a bacterial enzyme that catalyzes the dioxygen-dependent degradation of β-dicarbonyl compounds. The Dke1 active site contains a nonheme monoiron(II) center facially ligated by three histidine residues (the 3His triad); coordination of the substrate in a bidentate manner provides a five-coordinate site for O₂ binding. Recently, we published the synthesis and characterization of a series of ferrous β-diketonato complexes that faithfully mimic the enzyme–substrate intermediate of Dke1 (Park, H.; Baus, J.S.; Lindeman, S.V.; Fiedler, A.T. Inorg. Chem.2011, 50, 11978–11989). The 3His triad was modeled with three different facially coordinating N3 supporting ligands, and …

The Fe-Type Nitrile Hydratase From Comamonas Testosteroni Ni1 Does Not Require An Activator Accessory Protein For Expression In Escherichia Coli, Misty L. Kuhn, Salette Martinez, Natalie Gumataotao, Uwe Bornscheuer, Dali Liu, Richard C. Holz

Chemistry Faculty Research and Publications

We report herein the functional expression of an Fe-type nitrile hydratase (NHase) without the co-expression of an activator protein or the Escherichia coli chaperone proteins GroES/EL. Soluble protein was obtained when the α- and β-subunit genes of the Fe-type NHase Comamonas testosteroni Ni1 (CtNHase) were synthesized with optimized E. coli codon usage and co-expressed. As a control, the Fe-type NHase from Rhodococcus equi TG328–2 (ReNHase) was expressed with (ReNHase^+Act) and without (ReNHase^−Act) its activator protein, establishing that expression of a fully functional, metallated ReNHase enzyme requires the …

Spectroelectrochemical Elucidation Of The Kinetics Of Two Closely Spaced Electron Transfers, Robert L. Keesey, Michael D. Ryan

Chemistry Faculty Research and Publications

The use of spectroelectrochemistry to facilitate the analysis of an EE mechanism was reported in this work. Using a set of spectra as a function of potential, the spectra of all three oxidation states were determined using evolving window factor analysis. From these spectra, the concentration of each species in solution was determined for each potential. Using these data, the current was calculated. Unlike the direct measurement of current, the current due to each redox process was determined, allowing one to analyze each redox process separate from the other. With the use of the Butler–Volmer equation, the redox potential and …

Structural Characterization Of Zn(Ii)-, Co(Ii)-, And Mn(Ii)-Loaded Forms Of The Arge-Encoded N-Acetyl-L-Ornithine Deacetylase From Escherichia Coli, Ye Tao, Jacob E. Shokes, Wade C. Mcgregor, Robert A. Scott, Richard C. Holz

Chemistry Faculty Research and Publications

The Zn, Co, and Mn K-edge extended X-ray absorption fine structure (EXAFS) spectra of the N-acetyl-l-ornithine deacetylase (ArgE) from Escherichia coli, loaded with one or two equivalents of divalent metal ions (i.e., [Zn(II)_(ArgE)], [Zn(II)Zn(II)(ArgE)], [Co(II)_(ArgE)], [Co(II)Co(II)(ArgE)], [Mn(II)_(ArgE)], and [Mn(II)Mn(II)(ArgE)]), were recorded. The Fourier transformed data (FT) for [Zn(II)_(ArgE)], [Zn(II)Zn(II)(ArgE)], [Co(II)_(ArgE)] and [Co(II)Co(II)(ArgE)] are dominated by a peak at 2.05 Å, that can be fit assuming five or six light atom (N,O) scatterers. Inclusion of multiple-scattering contributions from the outer-shell atoms of a histidine-imidazole ring resulted in reasonable Debye–Waller factors for these contributions and a slight reduction …

Generation Of Molecular Complexity From Cyclooctatetraene Using Dienyliron And Olefin Metathesis Methodology, Mohamed F. El-Mansy, Anobick Sar, Subhabrata Chaudhury, Nathaniel J. Wallock, William A. Donaldson

Chemistry Faculty Research and Publications

Transformation of the simple hydrocarbon cyclooctatetraene into a variety of polycyclic skeletons was achieved by sequential coordination to iron, reaction with electrophiles followed by allylated nucleophiles, decomplexation and olefin metathesis.

A Density Functional Theory And Laser Flash Photolysis Investigation Of Carbofuran Photodegradation In Aqueous Medium, A. Atifi, M. Talipov, H. Mountacer, Michael D. Ryan, M. Sarakha

Chemistry Faculty Research and Publications

Density functional theory (DFT) approach was used to study the photodegradation of Carbofuran in aqueous medium. This computational method enables us to assign the electronic transitions and interpret the dissociative behavior upon irradiation based on a thermodynamical analysis of the bond dissociation energies (BDE) of Carbofuran. According to these calculations, phenoxy C---O bond appears weaker than the C---N bonds. Hence, it was predicted that the photodegradation of Carbofuran should occur with an initial homolytic dissociation of the C---O bond of the carbamate moiety. Laser Flash Photolysis (LFP) results clearly indicate the formation of the phenoxyl radical, which support the outcome …

On The Electronic Spectroscopy Of Closed Shell Cations Derived From Resonance Stabilized Radicals: Insights From Theory And Franck-Condon Analysis, T. P. Troy, S. H. Kable, T. W. Schmidt, Scott Reid

Chemistry Faculty Research and Publications

Context. Recent attention has been directed on closed-shell aromatic cations as potential carriers of the diffuse interstellar bands. The spectra of mass-selected, matrix-isolated benzylium, and tropylium cations were recently reported. The visible spectrum of benzylium exhibits a large Franck-Condon (FC) envelope, inconsistent with diffuse interstellar band carriers.

Aims. We perform a computational analysis of the experimentally studied benzylium spectrum before extending the methods to a range of larger, closed-shell aromatic cations to determine the potential for this class of systems as diffuse interstellar band carriers.

Methods. Density functional theory (DFT), time-dependent ((TD)DFT), and multi-configurational self-consistent field second-order perturbation theory (MRPT2) …

Assignments Of Backbone 1h, 13c And 15n Resonances In H-Ras (1–166) Complexed With Gppnhp At Physiological Ph, Casey O'Connor, Evgueni Kovriguine

Chemistry Faculty Research and Publications

The small GTPase Ras is an important signaling molecule acting as a molecular switch in eukaryotic cells. Recent findings of global conformational exchange and a putative allosteric binding site in the G domain of Ras opened an avenue to understanding novel aspects of Ras function. To facilitate detailed NMR studies of Ras in physiological solution conditions, we performed backbone resonance assignments of Ras bound to slowly hydrolysable GTP mimic, guanosine 5′-[ß, γ-imido]triphosphate at pH 7.2. Out of 163 non-proline residues of the G domain, signals from backbone amide proton, nitrogen and carbon spins of 127 residues were confidently assigned with …

Visible And Infrared Spectroelectrochemistry Of Cobalt Porphinones And Porphinediones, Florentina Tutunea, Michael D. Ryan

Chemistry Faculty Research and Publications

The visible and infrared spectroelectrochemistry of the redox chemistry of Co^II–porphinone complexes were examined and compared with similar studies of the respective iron complexes. Cobalt(II) porphinone complexes undergo a one-electron reduction and two one-electron oxidations within the potential region that was studied in this work. The one electron spectroelectrochemical reduction of Co^II(P) (P = octaethylporphyrin (OEP), octaethylporphinone (OEPone), and octaethylporphinedione (OEPdione)) were studied using visible spectroscopy, and their cobalt(I) complexes were characterized. The same reduction was examined by FTIR spectroscopy for P = OEPone and OEPdione. The infrared spectra showed downshifts of the ν_CO band …

Synthesis And Structural Characterization Of Iron(Ii) Complexes With Tris(Imidazolyl)Phosphane Ligands: A Platform For Modeling The 3-Histidine Facial Triad Of Nonheme Iron Dioxygenases, Michael M. Bittner, Jacob Baus, Sergey V. Lindeman, Adam T. Fiedler

Chemistry Faculty Research and Publications

Several monoiron(II) complexes containing tris(imidazolyl)phosphane (TIP) ligands have been prepared and structurally characterized by using X-ray crystallography and NMR spectroscopy. Two TIP ligands were employed: tris(2-phenylimidazol-4-yl)phosphane (4-TIP^Ph) and tris(4,5-diphenyl-1-methylimidazol-2-yl)phosphane (2-TIP^Ph2). These tridentate ligands resemble the 3-histidine (3His) facial triad found recently in the active sites of certain nonheme iron dioxygenases. Three of the reported complexes are designed to serve as convenient precursors to species that model the enzyme–substrate intermediates of 3His dioxygenases; thus, each contains an [Fe(κ³-TIP)]²⁺ unit in which the remaining coordination sites are occupied by easily displaced ligands, such as solvent …

Reactivity Of Tri(2-Furyl)Phosphine (Pfu3) With [Mn2(Co)10–N(Ncme)N] (N = 0–2): X-Ray Structure Of Mer-[Mn(Co)3(Η1-C4H3O)(Pfu3)2], Santana Karmaker, Shishir Ghosh, Shariff E. Kabir, Daniel T. Haworth, Sergey V. Lindeman

Chemistry Faculty Research and Publications

In the search for new examples of systems that self-assemble into cyclic metal–organic architectures, the six isomers of X,Y′-bis(di(1H-pyrazolyl)methane)-1,1′-biphenyl, L_XY, and their silver(I) trifluoromethanesulfonate complexes were prepared. Five of the six silver complexes gave crystals suitable for single crystal X-ray diffraction, with only the microcrystalline derivative of 2,3′-bis(di(1H-pyrazolyl)methane)-1,1′-biphenyl, L₂₃, proving to be unsuitable for this analysis. Of the structurally characterized silver(I) complexes, that with L₂₂ showed an unusual trans-spanning chelating coordination mode to silver. At the same time the ligand was also bound to a second silver center …

Scope And Mechanistic Study Of The Coupling Reaction Of Α,Β-Unsaturated Carbonyl Compounds With Alkenes: Uncovering Electronic Effects On Alkene Insertion Vs Oxidative Coupling Pathways, Ki Hyeok Kwon, Do W. Lee, Chae S. Yi

Chemistry Faculty Research and Publications

The cationic ruthenium-hydride complex [(C₆H₆)(PCy₃)(CO)RuH]⁺BF₄^– (1) was found to be a highly effective catalyst for the intermolecular conjugate addition of simple alkenes to α,β-unsaturated carbonyl compounds to give (Z)-selective tetrasubstituted olefin products. The analogous coupling reaction of cinnamides with electron-deficient olefins led to the oxidative coupling of two olefinic C–H bonds in forming (E)-selective diene products. The intramolecular version of the coupling reaction efficiently produced indene and bicyclic fulvene derivatives. The empirical rate law for the coupling reaction of ethyl cinnamate with propene was …

Charge Delocalization In Self-Assembled Mixed-Valence Aromatic Cation Radicals, Tushar Navale, Khushabu Thakur, Vijay Vyas, Shriya Wadumethrige, Ruchi Shukla, Sergey V. Lindeman, Rajendra Rathore

Chemistry Faculty Research and Publications

The spontaneous assembly of aromatic cation radicals (D^+•) with their neutral counterpart (D) affords dimer cation radicals (D₂^+•). The intermolecular dimeric cation radicals are readily characterized by the appearance of an intervalence charge-resonance transition in the NIR region of their electronic spectra and by ESR spectroscopy. The X-ray crystal structure analysis and DFT calculations of a representative dimer cation radical (i.e., the octamethylbiphenylene dimer cation radical) have established that a hole (or single positive charge) is completely delocalized over both aromatic moieties. The energetics and the geometrical considerations for the formation …

Recent Applications Of The Simple Hydrocarbon Cyclooctatetrene As A Starting Material For Complex Molecule Synthesis, Kevin W. Glaeske, William Donaldson

Chemistry Faculty Research and Publications

Cyclooctatetraene [COT], a simple non-aromatic cyclic polyene, is capable of undergoing a variety of oxidation and cycloaddition reactions to afford polycyclic structures. In addition, complexation of COT or the cycloaddition products with transition metals facilitates bond formation. Recent developments in the reactivity of COT and application to the synthesis of naturally occurring and non-naturally occurring compounds is reviewed.

Nmr Line Shapes And Multi-State Binding Equilibria, Evgeni Kovrigin

Chemistry Faculty Research and Publications

Biological function of proteins relies on conformational transitions and binding of specific ligands. Protein-ligand interactions are thermodynamically and kinetically coupled to conformational changes in protein structures as conceptualized by the models of pre-existing equilibria and induced fit. NMR spectroscopy is particularly sensitive to complex ligand-binding modes—NMR line-shape analysis can provide for thermodynamic and kinetic constants of ligand-binding equilibria with the site-specific resolution. However, broad use of line shape analysis is hampered by complexity of NMR line shapes in multi-state systems. To facilitate interpretation of such spectral patterns, I computationally explored systems where isomerization or dimerization of a protein (receptor) molecule …

Potential Energy And Dipole Moment Surfaces Of Hco- For The Search Of H- In The Interstellar Medium, M. Ayouz, I. Mikhailov, Dmitri Babikov, M. Raoult, S. Galtier, O. Dulieu, V. Kokoouline

Chemistry Faculty Research and Publications

Potential energy and permanent dipole moment surfaces of the electronic ground state of formyl negative ion HCO− are determined for a large number of geometries using the coupled-cluster theory with single and double and perturbative treatment of triple excitations ab initio method with a large basis set. The obtained data are used to construct interpolated surfaces, which are extended analytically to the region of large separations between CO and H− with the multipole expansion approach. We have calculated the energy of the lowest rovibrational levels of HCO− that should guide the spectroscopic characterization of HCO− in laboratory experiments. The study …

Spectroscopy And Dynamics Of The Predissociated, Quasi-Linear S2 State Of Chlorocarbene, Chong Tao, Craig A. Richmond, Calvin Mukarakate, S. H. Kable, Eric C. Brown, Richard Dawes, Phalgun Lolur, Scott Reid

Chemistry Faculty Research and Publications

In this work, we report on the spectroscopy and dynamics of the quasi-linear S₂ state of chlorocarbene, CHCl, and its deuterated isotopologue using optical-optical double resonance (OODR) spectroscopy through selected rovibronic levels of the S₁ state. This study, which represents the first observation of the S₂ state in CHCl, builds upon our recent examination of the corresponding state in CHF, where pronounced mode specificity was observed in the dynamics, with predissociation rates larger for levels containing bending excitation. In the present work, a total of 14 S₂ state vibrational levels with angular momentum ℓ = 1 …

A Chemical Proteomic Probe For Detecting Dehydrogenases: Catechol Rhodanine, Xia Ge, Daniel S. Sem

Chemistry Faculty Research and Publications

The inherent complexity of the proteome often demands that it be studied as manageable subsets, termed subproteomes. A subproteome can be defined in a number of ways, although a pragmatic approach is to define it based on common features in an active site that lead to binding of a common small molecule ligand (ex. a cofactor or a cross-reactive drug lead). The subproteome, so defined, can be purified using that common ligand tethered to a resin, with affinity chromatography. Affinity purification of a subproteome is described in the next chapter. That subproteome can then be analyzed using a common ligand …

Improved Potential Energy Surface Of Ozone Constructed Using The Fitting By Permutationally Invariant Polynomial Function, M. Ayouz, Dmitri Babikov

Chemistry Faculty Research and Publications

New global potential energy surface for the ground electronic state of ozone is constructed at the complete basis set level of the multireference configuration interaction theory. A method of fitting the data points by analytical permutationally invariant polynomial function is adopted. A small set of 500 points is preoptimized using the old surface of ozone. In this procedure the positions of points in the configuration space are chosen such that the RMS deviation of the fit is minimized. New ab initio calculations are carried out at these points and are used to build new surface. Additional points are added to …

Polysaccharide Ecocomposite Materials: Materials: Synthesis, Characterization And Application For Removal Of Pollutants And Bacteria, Simon Duri, Bilal El-Zahab, Chieu D. Tran

Chemistry Faculty Research and Publications

A novel, simple and totally recyclable method has been developed for the synthesis of nontoxic, biocompatible and biodegradable composite materials from cellulose and chitosan. In this method, [BMIm+Cl-], an ionic liquid (IL), was used as a solvent to dissolve and synthesize the [CEL+CS] composite materials. Since the IL can be removed from the materials by washing them with water, and recovered from the washed solution, the method is totally recyclable. XRD, FTIR, NIR and SEM were used to characterize the materials and to confirm that CEL and CS were successfully regenerated by the method without any chemical transformation. More importantly, …