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Full-Text Articles in Physical Sciences and Mathematics

Comparison Of Crystal Structures Of 4-(Benzo[B]Thiophen-2-Yl)-5-(3,4,5-Trimethoxyphenyl)-2H-1,2,3-Triazole And 4-(Benzo[B]Thiophen-2-Yl)-2-Methyl-5-(3,4,5-Trimethoxyphenyl)-2H-1,2,3-Triazole, Narsimha Reddy Penthala, Nikhil Reddy Madadi, Shobanbabu Bommagani, Sean Parkin, Peter A. Crooks Nov 2014

Comparison Of Crystal Structures Of 4-(Benzo[B]Thiophen-2-Yl)-5-(3,4,5-Trimethoxyphenyl)-2H-1,2,3-Triazole And 4-(Benzo[B]Thiophen-2-Yl)-2-Methyl-5-(3,4,5-Trimethoxyphenyl)-2H-1,2,3-Triazole, Narsimha Reddy Penthala, Nikhil Reddy Madadi, Shobanbabu Bommagani, Sean Parkin, Peter A. Crooks

Chemistry Faculty Publications

The title compound, C19H17N3O3S (I), was prepared by a [3 + 2]cyclo­addition azide condensation reaction using sodium azide and l-proline as a Lewis base catalyst. N-Methyl­ation of compound (I) using CH3I gave compound (II), C20H19N3O3S. The benzo­thio­phene ring systems in (I) and (II) are almost planar, with r.m.s deviations from the mean plane = 0.0205 (14) in (I) and 0.016 (2) Å in (II). In (I) and (II), the triazole rings make dihedral angles of 32.68 (5) and 10.43 (8)°, respectively, …


Crystal Structure Of 4,5-Bis-(3,4,5-Trimethoxyphenyl)-2H-1,2,3-Triazole Methanol Monosolvate, Nikhil Reddy Madadi, Narsimha Reddy Penthala, Shobanbabu Bommagani, Sean Parkin, Peter A. Crooks Oct 2014

Crystal Structure Of 4,5-Bis-(3,4,5-Trimethoxyphenyl)-2H-1,2,3-Triazole Methanol Monosolvate, Nikhil Reddy Madadi, Narsimha Reddy Penthala, Shobanbabu Bommagani, Sean Parkin, Peter A. Crooks

Chemistry Faculty Publications

The title compound, C20H23N3O6·CH3OH, was synthesized by [3 + 2] cyclo­addition of (Z)-2,3-bis­(3,4,5-tri­meth­oxy­phen­yl)acrylo­nitrile with sodium azide and ammonium chloride in DMF/water. The central nitro­gen of the triazole ring is protonated. The dihedral angles between the triazole ring and the 3,4,5-tri­meth­oxy­phenyl ring planes are 34.31 (4) and 45.03 (5)°, while that between the 3,4,5-tri­meth­oxy­phenyl rings is 51.87 (5)°. In the crystal, the mol­ecules, along with two methanol solvent mol­ecules are linked into an R 4 4(10) centrosymmetric dimer by N—H⋯O and O—H⋯N hydrogen bonds.


Crystal Structure Of (E)-13-{4-[(Z)-2-Cyano-2-(3,4,5-Trimethoxyphenyl)Ethenyl]Phenyl}Parthenolide Methanol Hemisolvate, Narsimha Reddy Penthala, Shobanbabu Bommagani, Venumadhav Janganati, Sean Parkin, Peter A. Crooks Oct 2014

Crystal Structure Of (E)-13-{4-[(Z)-2-Cyano-2-(3,4,5-Trimethoxyphenyl)Ethenyl]Phenyl}Parthenolide Methanol Hemisolvate, Narsimha Reddy Penthala, Shobanbabu Bommagani, Venumadhav Janganati, Sean Parkin, Peter A. Crooks

Chemistry Faculty Publications

The title compound, C33H35NO6 [systematic name: (Z)-3-(4-{(E)-[(E)-1a,5-dimethyl-9-oxo-2,3,7,7a-tetra­hydro­oxireno[2′,3′:9,10]cyclo­deca­[1,2-b]furan-8(1aH,6H,9H,10aH,10bH)-yl­idene]meth­yl}phen­yl)-2-(3,4,5-tri­meth­oxy­phen­yl)acrylo­ni­trile methanol hemisolvate], C33H35NO6·0.5CH3OH, was prepared by the reaction of (Z)-3-(4-iodo­phen­yl)-2-(3,4,5-tri­meth­oxy­phen­yl)acrylo­nitrile with parthenolide [systematic name: (E)-1a,5-dimethyl-8-methyl­ene-2,3,6,7,7a,8,10a,10b-octa­hy­dro­oxireno[2′,3′:9,10]cyclo­deca­[1,2-b]furan-9(1aH)-one] under Heck reaction conditions. The mol­ecule is built up from fused ten-, five- (lactone) and three-membered (epoxide) rings with a {4-[(Z)-2-cyano-2-(3,4,5-tri­meth­oxy­phen­yl)ethen­yl]phen­yl}methyl­idene group as a substituent. The 4-[(Z)-2-cyano-2-(3,4,5-tri­meth­oxy­phen­yl)ethen­yl]phenyl group on the parthenolide exocyclic double bond is …


Crystal Structure Of 1-Methoxy-2,2,2-Tris(Pyrazol-1-Yl)Ethane, Ganna Lyubartseva, Sean Parkin, Morgan D. Coleman, Uma Prasad Mallik Sep 2014

Crystal Structure Of 1-Methoxy-2,2,2-Tris(Pyrazol-1-Yl)Ethane, Ganna Lyubartseva, Sean Parkin, Morgan D. Coleman, Uma Prasad Mallik

Chemistry Faculty Publications

The title compound, C12H14N6O, consists of three pyrazole rings bound via nitro­gen to the distal ethane carbon of meth­oxy ethane. The dihedral angles between the three pyrazole rings are 67.62 (14), 73.74 (14), and 78.92 (12)°. In the crystal, mol­ecules are linked by bifurcated C—H,H⋯N hydrogen bonds, forming double-stranded chains along [001]. The chains are linked via C—H⋯O hydrogen bonds, forming a three-dimensional framework structure. The crystal was refined as a perfect (0.5:0.5) inversion twin.


Low-Temperature Phase Transitions In A Soluble Oligoacene And Their Effect On Device Performance And Stability, J. W. Ward, K. P. Goetz, A. Obaid, Marcia M. Payne, P. J. Diemer, C. S. Day, John E. Anthony, O. D. Jurchescu Aug 2014

Low-Temperature Phase Transitions In A Soluble Oligoacene And Their Effect On Device Performance And Stability, J. W. Ward, K. P. Goetz, A. Obaid, Marcia M. Payne, P. J. Diemer, C. S. Day, John E. Anthony, O. D. Jurchescu

Chemistry Faculty Publications

The use of organic semiconductors in high-performance organic field-effect transistors requires a thorough understanding of the effects that processing conditions, thermal, and bias-stress history have on device operation. Here, we evaluate the temperature dependence of the electrical properties of transistors fabricated with 2,8-difluoro-5,11-bis(triethylsilylethynyl)anthradithiophene, a material that has attracted much attention recently due to its exceptional electrical properties. We have discovered a phase transition at T = 205 K and discuss its implications on device performance and stability. We examined the impact of this low-temperature phase transition on the thermodynamic, electrical, and structural properties of both single crystals and thin films …


A Low Temperature Nonlinear Optical Rotational Anisotropy Spectrometer For The Determination Of Crystallographic And Electronic Symmetries, Darius H. Torchinsky, Hao Chu, Tongfei Qi, Gang Cao, David Hsieh Aug 2014

A Low Temperature Nonlinear Optical Rotational Anisotropy Spectrometer For The Determination Of Crystallographic And Electronic Symmetries, Darius H. Torchinsky, Hao Chu, Tongfei Qi, Gang Cao, David Hsieh

Center for Advanced Materials Faculty Publications

Nonlinear optical generation from a crystalline material can reveal the symmetries of both its lattice structure and underlying ordered electronic phases and can therefore be exploited as a complementary technique to diffraction based scattering probes. Although this technique has been successfully used to study the lattice and magnetic structures of systems such as semiconductor surfaces, multiferroic crystals, magnetic thin films, and multilayers, challenging technical requirements have prevented its application to the plethora of complex electronic phases found in strongly correlated electron systems. These requirements include an ability to probe small bulk single crystals at the μm length scale, a need …