Research Highlights

Dr. Xin Cui research

Congratulations to The Cui Group on their most recent publication. https://pubs.acs.org/doi/10.1021/acscatal.0c02676 Qian X.; Zhou, H.; Chaminda Lakmal, H. H.; Lucore, J. (undergraduate researcher); Wang, X.; Valle, U. H.; Donnadieu, B.; Xu X.; Cui X.* “Fe(III)-Based Tandem Catalysis for Amidomethylative Multiple Substitution Reactions of α-...

Fe3O4 Nanoparticles Dispersed on Douglas Fir Biochar for Phosphate Sorption

The recent work by Todd Mlsna group has been featured on the front cover of ACS Applied Nano Materials (June issue). This graphic illustrates chemically coprecipitated magnetite (Fe3O4) nanoparticles (~16.7 nm diameter) dispersed on a high-surface-area (~695 m2/g) syn gas by product Douglas fir biochar. The...

Pharmaceuticals of Emerging Concern in Aquatic Systems: Chemistry, Occurrence, Effects, and Removal Methods

In the last few decades, pharmaceuticals, credited with saving millions of lives, have emerged as a new class of environmental contaminant. These compounds can have both chronic and acute harmful effects on natural flora and fauna. The presence of pharmaceutical contaminants in ground waters, surface waters (lakes, rivers, and streams), sea water...

Determination of Xylitol in Sugar-Free Gum by GC–MS with Direct Aqueous Injection: A Laboratory Experiment for Chemistry Student

• Xylitol is generally considered safe for human consumption and is frequently used in sugar free gum; however, it is extremely toxic to dogs.• In this laboratory experiment, upper-level undergraduate chemistry students extract xylitol from both fresh and chewed gum sticks followed by direct aqueous injection GC-MS analysis.• Students learn the...

Acenaphthylene Derived Perfluorocyclobutyl (PFCB) Aromatic Ether Polymers

Double nucleophilic addition of established Grignard reagent, p-MgBr-C6H4-OCF=CF2, to acenapthenequinone afforded the corresponding diol, which upon treatment with TiCl4 / NEt3 was converted in a single-pot reaction to the bis-trifluorovinyl ether (TFVE) containing ring-cleaved dione and ring-retained...

Thermodynamics of Iron(II) and Substrate Binding to the Ethylene-Forming Enzyme

The ethylene-forming enzyme (EFE) catalyzes the oxidative decarboxylation of 2OG to succinate and CO2 to generate a highly reactive iron species that hydroxylates a specific alkane C–H bond, in this case targeting l-arginine (Arg) for hydroxylation. However, the prominently observed reactivity of EFE is the transformation of 2OG into...

NaHS Induced Complete Ligand Displacement from Gold Nanoparticles

The Zhang Group demonstrated that NaHS induces complete displacement of ligands from AuNPs. The model ligands include the aliphatic and aromatic monothiols, organodithiols, thioamides, and nonspecific ligand such as adenine. HS_ adsorbed as a monolayer on AuNP through formation of S-Au bonds and S-S bonds with no detection S-H features. ...

Facile Displacement of Citrate Residues from Gold Nanoparticle (AuNP) Surfaces

Using gold nanoparticles (AuNPs) synthesized with deuterated citrate, the Zhang Group demonstrated that the surface of citrate-reduced AuNPs contains both deuterium-bearing citrate-derivative and hydrogen-bearing solvent impurities.  The deuterium-bearing citrate derivatives can be readily displaced from AuNPs by organothiols, organodisufide, and...

New Insights to the Porphyrin Assembly and Disassembly

The Zhang Group investigated porphyrin assembly and disassembly with their newly developed Polarized Resonance Synchronous Spectroscopy (PRS2) technique.  In contrast to existing literature that claims an inductive period in the porphyrin assembly process, porphyrin aggregation occurs instantaneously acidification. The time-resolved PRS2 spectra...

Scattering and Absorption Differ Drastically in Their Inner Filter Effects

Both photon absorption and scattering contribute to the photon extinction measured with UV-vis spectrophotometers.  However, only absorption extinction induces strong inner-filter-effect (IFE) while extinction by light scattering has no significant IFE. Therefore, one should always decompose the sample UV-vis extinction spectrum into its...

Separation of Fluorescence and Light Scattering

The Zhang Group discovered that both light scattering and fluorescence (not light scattering alone assumed in existing literature) can contribute to the resonance synchronous spectroscopy obtained with fluorescent samples. Presented is a ratiometric Bandwidth Varied Polarized Resonance Synchronous Spectroscopy (BVPRS2) method for separating...

Optical Spectroscopic Constants for Gold Nanoparticles Image

Using polarized resonance synchronous spectroscopic technique recently invented by them, the Zhang Group quantified the extinction, scattering, absorption cross-sections, and scattering depolarization spectra for a series of gold nanoparticles (AuNPs) of different sizes and shapes.  The scattering depolarization is sensitive to AuNP geometry,...

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The Webster Group and collaborators report the first self-sensitized homogeneous photocatalyst for H2 production. A previously reported di-Fe complex (a biomimetic of the Fe-Fe hydrogenase active site) achieved a TON of 3 over 3 hours. We have investigated a purely synthetic, mononuclear W-NHC complex that achieves a TON of 17 over 3...

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The Webster Group and collaborators report the excited state (ES) linkage isomerization of a series of ruthenium complexes bearing a chelating triphenylphosphine-based sulfoxide ligand. The isomerization can be allowed (ΦS→O = 0.8) or forbidden (ΦS→O = 0.0) based on the remote [from ruthenium] substituents of the phosphine...

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The Webster Group reports a previously uncharacterized “closed” Cs-symmetric agostomer of cyclohexenylmanganese tricarbonyl [(C6H9)Mn(CO)3] using DFT computations. Excellent agreement (R2 = 0.9949) between the computed and experimental 1H NMR chemical shifts is observed. Reasonable...

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The Webster and Hollis Groups report the extreme π-loading (CCC-NHC) pincer Ta(V) bis(imido) complex that catalyzes the cyclization of α,ω-aminoalkene (2,2-diphenylpent-4-en-1-amine) to produce three different products in varying proportions: cyclic imine from oxidative amination (OA), reduction product (RP) from hydrogenated substrate, and...

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The Webster Group and collaborators report structural modifications of molecular cobalt catalysts that provide important insights into the structure–function relationship for the hydrogen evolution reaction. Despite a slight structural difference of the introduced isoquinoline group, the cobalt complex [Co(DPA-1-MPI)(H2O)](PF6...

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The Cui Group has developed a practical and direct synthetic access to saturated cyclic compounds by catalytic [2+2+2] reactions of simple alkenes. Indium-catalyzed [2+2+2] cycloaddition has been proven effective for the direct construction of hexahydropyrimidines, a class of pharmaceutically related compounds, from both alkenes and allenes. This...

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The Cui Group and collaborators have developed an operationally simple and direct synthesis of 1,2-disulfonyl-1,2-diazetidine derivatives, a unique class of highly strained N-heterocycles, via a one-step intermolecular dialkylation reaction. Structural features of these distinctive cyclic systems have been understood by experimental and...