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Full-Text Articles in Inorganic Chemistry
Epitaxial Electrodeposition Of Cu-Btc Metal-Organic Framework Thin Films Onto The (100), (110), And (111) Surfaces Of Single-Crystal Gold And Cuprous Oxide Buffer Layers, Xiaoting Zhang, John Z. Tubbesing, Jay A. Switzer
Epitaxial Electrodeposition Of Cu-Btc Metal-Organic Framework Thin Films Onto The (100), (110), And (111) Surfaces Of Single-Crystal Gold And Cuprous Oxide Buffer Layers, Xiaoting Zhang, John Z. Tubbesing, Jay A. Switzer
Chemistry Faculty Research & Creative Works
Metal-organic frameworks (MOFs) have well-defined pore structures. Epitaxial MOFs can produce films with uniform pore sizes and open porosity. However, the growth of epitaxial MOF thin films has remained a challenge. Herein, we demonstrate a cathodic electrodeposition method for the epitaxial growth of a well-known MOF material, copper (II)-benzene-1,3,5-tricarboxylate (Cu-BTC), from solution precursors. The epitaxial electrodeposition of Cu-BTC was achieved in a Cu (NO3)2-H3BTC-H2O2 bath using H2O2 reduction to deprotonate the H3BTC molecule. The Cu-BTC films can be grown to micrometer thicknesses with Faradaic efficiencies up …
Comparative Nitrene-Transfer Chemistry To Olefins Mediated By First-Row Transition Metal Catalysts Supported By A Pyridinophane Macrocycle With N4 Ligation, Himanshu Bhatia, Lillian P. Adams, Ingrid Cordsiemon, Suraj Kumar Sahoo, Amitava Choudhury, Thomas R. Cundari, Pericles Stavropoulos
Comparative Nitrene-Transfer Chemistry To Olefins Mediated By First-Row Transition Metal Catalysts Supported By A Pyridinophane Macrocycle With N4 Ligation, Himanshu Bhatia, Lillian P. Adams, Ingrid Cordsiemon, Suraj Kumar Sahoo, Amitava Choudhury, Thomas R. Cundari, Pericles Stavropoulos
Chemistry Faculty Research & Creative Works
A 12-membered pyridinophane scaffold containing two pyridine and two tertiary amine residues is examined as a prototype ligand (tBuN4) for supporting nitrene transfer to olefins. The known [(tBuN4)MII(MeCN)2]2+ (M = Mn, Fe, Co, and Ni) and [(tBuN4)CuI(MeCN)]+ cations are synthesized with the hexafluorophosphate counteranion. The aziridination of para-substituted styrenes with PhI=NTs (Ts = tosyl) in various solvents proved to be high yielding for the Cu(I) and Cu(II) reagents, in contrast to the modest efficacy of all other metals. For α-substituted styrenes, aziridination is accompanied by products of aziridine …
C-H Amination Chemistry Mediated By Trinuclear Cu(I) Sites Supported By A Ligand Scaffold Featuring An Arene Platform And Tetramethylguanidinyl Residues, Meenakshi Sharma, Reece M. Fritz, Himanshu Bhatia, Joseph O. Adebanjo, Zhou Lu, Mohammad A. Omary, Thomas R. Cundari, Amitava Choudhury, Pericles Stavropoulos
C-H Amination Chemistry Mediated By Trinuclear Cu(I) Sites Supported By A Ligand Scaffold Featuring An Arene Platform And Tetramethylguanidinyl Residues, Meenakshi Sharma, Reece M. Fritz, Himanshu Bhatia, Joseph O. Adebanjo, Zhou Lu, Mohammad A. Omary, Thomas R. Cundari, Amitava Choudhury, Pericles Stavropoulos
Chemistry Faculty Research & Creative Works
Tripodal ligands that can encapsulate single or multiple metal sites in C3-symmetric geometric configurations constitute valuable targets for novel catalysts. Of particular interest in ligand development are efforts toward incorporating apical elements that exhibit little if any electron donicity, to enhance the electrophilic nature of a trans positioned active oxidant (e.g., metal-oxo, -nitrene). The tripodal ligand TMG3trphen-Arene has been synthesized, featuring an arene platform 1,3,5-substituted with phenylene arms possessing tetramethylguanidinyl (TMG) residues. Compound [(TMG3trphen-Arene) Cu3(μ-Cl)3] has been subsequently synthesized by extracting a Cu3(μ-Cl)3 cluster from anhydrous CuCl and shown to encapsulate a crown-shaped …
Chiral Recognition Of Chiral (Hetero)Cyclic Derivatives Probed By Tetraaza Macrocyclic Chiral Solvating Agents Via ¹H Nmr Spectroscopy, Yu Wang, Hongmei Zhao, Chunxia Yang, Lixia Fang, Li Zheng, Hehua Lv, Pericles Stavropoulos, Lin Ai, Jiaxin Zhang
Chiral Recognition Of Chiral (Hetero)Cyclic Derivatives Probed By Tetraaza Macrocyclic Chiral Solvating Agents Via ¹H Nmr Spectroscopy, Yu Wang, Hongmei Zhao, Chunxia Yang, Lixia Fang, Li Zheng, Hehua Lv, Pericles Stavropoulos, Lin Ai, Jiaxin Zhang
Chemistry Faculty Research & Creative Works
In the Field of Chiral Recognition, Chiral Cyclic Organic Compounds, Especially Heterocyclic Organic Compounds, Have Attracted Little Attention and Have Been Rarely Studied as Chiral Substrates by Means of 1H NMR Spectroscopy. in This Paper, Enantiomers of Thiohydantoin Derivatives, Representing Typical Five-Membered N,N-Heterocycles, Have Been Synthesized and Utilized for Assignment of Absolute Configuration and Analysis of Enantiomeric Excess. All Enantiomers Have Been Successfully Differentiated with the Assistance of Novel Tetraaza Macrocyclic Chiral Solvating Agents (TAMCSAs) by 1H NMR Spectroscopy. Surprisingly, Unprecedented Nonequivalent Chemical Shift Values (Up to 2.052 Ppm) of the NH Proton of Substrates Have Been Observed, a New …
Nitrene-Transfer Chemistry To C-H And C═C Bonds Mediated By Triangular Coinage Metal Platforms Supported By Triply Bridging Pnictogen Elements Sb(Iii) And Bi(Iii), Meenakshi Sharma, Reece M. Fritz, Joseph O. Adebanjo, Zhou Lu, Thomas R. Cundari, Mohammad A. Omary, Amitava Choudhury, Pericles Stavropoulos
Nitrene-Transfer Chemistry To C-H And C═C Bonds Mediated By Triangular Coinage Metal Platforms Supported By Triply Bridging Pnictogen Elements Sb(Iii) And Bi(Iii), Meenakshi Sharma, Reece M. Fritz, Joseph O. Adebanjo, Zhou Lu, Thomas R. Cundari, Mohammad A. Omary, Amitava Choudhury, Pericles Stavropoulos
Chemistry Faculty Research & Creative Works
Tripodal Ligands (TMG3trphen-E) That Feature Heavy Pnictogen Elements (E = Sb(III), Bi(III)) And Tetramethylguanidinyl (TMG) Arms Have Been Explored In Stabilizing Cu(I) And Ag(I) Sites And Facilitating Nitrene-Transfer Chemistry. Compounds [(TMG3trphen-E)M3(Μ-X)3] (M = Cu(I), Ag(I); X = Cl, Br, I) Have Been Generated Upon Extraction Of M3(Μ-X)3 Units From MX Sources, Exhibiting Support Of The Crown-Shaped M3(Μ-X)3 Fragment By M-NTMG Bonds And Triply Bridging E → M3 Interactions. Orbital Interactions Between Cu(I) Sites And NTMG Residues Are More Dominant Than Sb/Bi → Cu3 Donor Interactions Between The Sb 5s Or Bi 6s Orbitals And Admixed Cu 4s/3d Orbitals, With Larger …
A Comparative Study Of Cationic Copper(I) Reagents Supported By Bipodal Tetramethylguanidinyl-Containing Ligands As Nitrene-Transfer Catalysts, Suraj Kumar Sahoo, Brent Harfmann, Himanshu Bhatia, Harish Singh, Srikanth Balijapelly, Amitava Choudhury, Pericles Stavropoulos
A Comparative Study Of Cationic Copper(I) Reagents Supported By Bipodal Tetramethylguanidinyl-Containing Ligands As Nitrene-Transfer Catalysts, Suraj Kumar Sahoo, Brent Harfmann, Himanshu Bhatia, Harish Singh, Srikanth Balijapelly, Amitava Choudhury, Pericles Stavropoulos
Chemistry Faculty Research & Creative Works
The Bipodal Compounds [(TMG2biphenN-R)CuI-NCMe](PF6) (R = Me, Ar (4-CF3Ph-)) And [(TMG2biphenN-Me)CuI-I] Have Been Synthesized With Ligands That Feature A Diarylmethyl- And Triaryl-Amine Framework And Superbasic Tetramethylguanidinyl Residues (TMG). The Cationic Cu(I) Sites Mediate Catalytic Nitrene-Transfer Reactions Between The Imidoiodinane PhI = NTs (Ts = Tosyl) And A Panel Of Styrenes In MeCN, To Afford Aziridines, Demonstrating Comparable Reactivity Profiles. The Copper Reagents Have Been Further Explored To Execute C-H Amination Reactions With A Variety Of Aliphatic And Aromatic Hydrocarbons And Two Distinct Nitrene Sources PhI = NTs And PhI = NTces (Tces = 2,2,2-Trichloroethylsulfamate) In Benzene/HFIP (10:2 V/v). Good Yields …
Cationic Divalent Metal Sites (M = Mn, Fe, Co) Operating As Both Nitrene-Transfer Agents And Lewis Acids Toward Mediating The Synthesis Of Three- And Five-Membered N-Heterocycles, Suraj Kumar Sahoo, Brent Harfmann, Lin Ai, Qiuwen Wang, Sudip Mohapatra, Amitava Choudhury, Pericles Stavropoulos
Cationic Divalent Metal Sites (M = Mn, Fe, Co) Operating As Both Nitrene-Transfer Agents And Lewis Acids Toward Mediating The Synthesis Of Three- And Five-Membered N-Heterocycles, Suraj Kumar Sahoo, Brent Harfmann, Lin Ai, Qiuwen Wang, Sudip Mohapatra, Amitava Choudhury, Pericles Stavropoulos
Chemistry Faculty Research & Creative Works
The tripodal compounds [(TMG3trphen)MII-solv](PF6)2 (M = Mn, Fe, Co; solv = MeCN, DMF) and bipodal analogues [(TMG2biphen)MII(NCMe)x](PF6)2 (x = 3 for Mn, Fe; x = 2 for Co) and [(TMG2biphen)MIICl2] have been synthesized with ligands that feature a triaryl- or diarylmethyl-amine framework and superbasic tetramethylguanidinyl residues (TMG). The dicationic M(II) sites mediate catalytic nitrene-transfer reactions between the imidoiodinane PhI═NTs (Ts = tosyl) and a panel of styrenes in MeCN to afford aziridines and low yields of imidazolines (upon …
Epitaxial Single-Domain Cu-Btc Metal-Organic Framework Thin Films And Foils By Electrochemical Conversion Of Cuprous Oxide, Xiaoting Zhang, Bin Luo, Avishek Banik, John Z. Tubbesing, Jay A. Switzer
Epitaxial Single-Domain Cu-Btc Metal-Organic Framework Thin Films And Foils By Electrochemical Conversion Of Cuprous Oxide, Xiaoting Zhang, Bin Luo, Avishek Banik, John Z. Tubbesing, Jay A. Switzer
Chemistry Faculty Research & Creative Works
Metal-Organic Frameworks (MOFs) Are an Important Class of Crystalline Porous Materials with Extensive Chemical and Structural Merits. However, the Fabrication of MOF Thin Films Oriented Along All Crystallographic Axes to Achieve Well-Aligned Nanopores and Nanochannels with Uniform Apertures Remains a Challenge. Here, We Achieved Highly Crystalline Single-Domain MOF Thin Films with the [111] Out-Of-Plane Orientation by Electrochemical Conversion of Cuprous Oxide. Copper(II)-Benzene-1,3,5-Tricarboxylate, Cu3(BTC)2 (Referred to as Cu-BTC), is a Well-Known Metal-Organic Open Framework Material with a Cubic Crystal System. Epitaxial Cu-BTC(111) Thin Films Were Manufactured by Electrochemical Oxidation of Cu2O(111) Films Electrodeposited on Single-Crystal Au(111). …
Epitaxial Electrodeposition Of Ordered Inorganic Materials, Jay A. Switzer, Avishek Banik
Epitaxial Electrodeposition Of Ordered Inorganic Materials, Jay A. Switzer, Avishek Banik
Chemistry Faculty Research & Creative Works
Conspectus The quality of technological materials generally improves as the crystallographic order is increased. This is particularly true in semiconductor materials, as evidenced by the huge impact that bulk single crystals of silicon have had on electronics. Another approach to producing highly ordered materials is the epitaxial growth of crystals on a single-crystal surface that determines their orientation. Epitaxy can be used to produce films and nanostructures of materials with a level of perfection that approaches that of single crystals. It may be used to produce materials that cannot be grown as large single crystals due to either economic or …
An Electrodeposited Inhomogeneous Metal-Insulator-Semiconductor Junction For Efficient Photoelectrochemical Water Oxidation, James C. Hill, Alan T. Landers, Jay A. Switzer
An Electrodeposited Inhomogeneous Metal-Insulator-Semiconductor Junction For Efficient Photoelectrochemical Water Oxidation, James C. Hill, Alan T. Landers, Jay A. Switzer
Chemistry Faculty Research & Creative Works
The photoelectrochemical splitting of water into hydrogen and oxygen requires a semiconductor to absorb light and generate electron-hole pairs, and a catalyst to enhance the kinetics of electron transfer between the semiconductor and solution. A crucial question is how this catalyst affects the band bending in the semiconductor, and, therefore, the photovoltage of the cell. We introduce a simple and inexpensive electrodeposition method to produce an efficient n-Si/SiOx/Co/CoOOH photoanode for the photoelectrochemical oxidation of water to oxygen. The photoanode functions as a solid-state, metal-insulator-semiconductor photovoltaic cell with spatially non-uniform barrier heights in series with a low overpotential water-splitting electrochemical cell. …
Combined Mössbauer Spectral And Density Functional Theory Determination Of The Magnetic Easy-Axis In Two High-Spin Iron(Ii) 2-Pyrazinecarboxylate Complexes, Gary J. Long, Stefania Tanase, Françoise Remacle, Ganga Periyasamy, Fernande Grandjean
Combined Mössbauer Spectral And Density Functional Theory Determination Of The Magnetic Easy-Axis In Two High-Spin Iron(Ii) 2-Pyrazinecarboxylate Complexes, Gary J. Long, Stefania Tanase, Françoise Remacle, Ganga Periyasamy, Fernande Grandjean
Chemistry Faculty Research & Creative Works
A combination of density functional theory (DFT) calculations and Mössbauer spectroscopy has been used to determine that the magnetic easy-axis is coincident with its crystallography c-axis in [Fe(pca) 2(py)2] · py, where pac is the 2- pyrazinecarboxylate ligand. This easy-axis bisects the approximately axial O-Fe-O coordination axes of molecules adjacent to each other along the c-axis. in {[Fe(pca)2(H2O)]-H2O) n the easy magnetic axis is not coincident with any of its crystallographic axes nor with the Fe-O(water) coordination axis, but is coincident with one of the Fe ... Fe axes in the crystal structure. the DFT calculations, …
Synthetic, Structural, Magnetic, And Mössbauer Spectral Study Of {Fe[Hc(3,5-Me2pz)3]2}I2 And Its Spin-State Crossover Behavior, Daniel L. Reger, Christine A. Little, Mark D. Smith, Arnold L. Rheingold, Kin Chung Lam, Thomas L. Concolino, Gary J. Long, Raphaël P. Hermann, Fernande Grandjean
Synthetic, Structural, Magnetic, And Mössbauer Spectral Study Of {Fe[Hc(3,5-Me2pz)3]2}I2 And Its Spin-State Crossover Behavior, Daniel L. Reger, Christine A. Little, Mark D. Smith, Arnold L. Rheingold, Kin Chung Lam, Thomas L. Concolino, Gary J. Long, Raphaël P. Hermann, Fernande Grandjean
Chemistry Faculty Research & Creative Works
The complex {Fe [HC(3,5-Me2pz)3]2} I2 (1) has been prepared from the reaction of FeI2 and HC(3,5-Me2pz)3 (pz = pyrazolyl ring) in a 1:2 ratio. The complex is high spin in both the solid state and in solution at ambient temperature. In the solid state, magnetic susceptibility and Mössbauer spectral studies indicate that samples of the complex that have been crystallized and dried change completely from high-spin to low-spin upon cooling below 195 K, with a substantial two-step thermal hysteresis in the transition. The spin-crossover properties of 1 are sample …
A Structural, Magnetic, And Mössbauer Spectral Study Of Dy2fe17 And Its Hydrides, O. Isnard, Dimitri Hautot, Gary J. Long, Fernande Grandjean
A Structural, Magnetic, And Mössbauer Spectral Study Of Dy2fe17 And Its Hydrides, O. Isnard, Dimitri Hautot, Gary J. Long, Fernande Grandjean
Chemistry Faculty Research & Creative Works
The structural and magnetic properties of the [formula omitted] compounds, where x is 0, 1, 2, 3, and 3.8, have been investigated by means of powder x-ray diffraction, thermomagnetic and ac magnetic susceptibility measurements, and iron-57 Mössbauer spectroscopy. The Dy2Fe17Hx compounds crystallize in a hexagonal Th2Ni17 -like structure which has both an iron-rich stoichiometry and disorder of the Dy and Fe–Fe dumbbell sites. The increase in the lattice parameters, the magnetic ordering temperature, the saturation magnetization, and the dependence of the Mössbauer hyperfine parameters upon hydrogen content support a two-step filling by …