Synthesis, Structural Characterization, and Optical Properties of Benzene-Fused Tetracyclic and Pentacyclic Stiboles

The expectation that antimony (Sb) compounds should display phosphorescence emissions based on the “heavy element effect” prompted our interest in the introduction of antimony to a biaryl as the bridging atom in a fused heterole system. Herein, the synthesis, molecular structures, and optical properties of novel benzene-fused heteroacenes containing antimony or arsenic atoms are described. The stiboles and arsole were prepared by the condensation of dibromo(phenyl)stibane or dichloro(phenyl)arsine with dilithium intermediates derived from the corresponding dibromo compounds. Nuclear magnetic resonance (NMR) spectroscopy and X-ray crystal analysis revealed that the linear pentacyclic stibole was highly symmetric in both the solution and crystal states. In contrast, the curved pentacyclic stibole adopted a helical structure in solution, and surprisingly, only M helical molecules were crystallized from the racemate. All synthesized compounds produced very weak or no emissions at room temperature or in the solid state. In contrast, the linear penta- and tetracyclic stiboles exhibited clear phosphorescence emissions in the CHCl3 frozen matrix at 77 K under aerobic conditions.

Download Full-text

Synthesis, structural characterization and catalytic activity of chlororuthenium(II) complexes with substituted Schiff base/phosphine ancillary ligands

Zeitschrift für Naturforschung B ◽

10.1515/znb-2020-0110 ◽

2020 ◽

Vol 75 (9-10) ◽

pp. 851-857

Author(s):

Chong Chen ◽

Fule Wu ◽

Jiao Ji ◽

Ai-Quan Jia ◽

Qian-Feng Zhang

Keyword(s):

Schiff Base ◽

Catalytic Activity ◽

Structural Characterization ◽

Room Temperature ◽

Molecular Structures ◽

Cationic Complex ◽

Neutral Complex ◽

Ancillary Ligands ◽

X Ray ◽

X Ray Crystallography

AbstractTreatment of [(η6-p-cymene)RuCl2]2 with one equivalent of chlorodiphenylphosphine in tetrahydrofuran at reflux afforded a neutral complex [(η6-p-cymene)RuCl2(κ1-P-PPh2OH)] (1). Similarly, the reaction of [Ru(bpy)2Cl2·2H2O] (bpy = 2,2′-bipyridine) and chlorodiphenylphosphine in methanol gave a cationic complex [Ru(bpy)2Cl(κ1-P-PPh2OCH3)](PF6) (2), while treatment of [RuCl2(PPh3)3] with [2-(C5H4N)CH=N(CH2)2N(CH3)2] (L1) in tetrahydrofuran at room temperature afforded a ruthenium(II) complex [Ru(PPh3)Cl2(κ3-N,N,N-L1)] (3). Interaction of the chloro-bridged complex [Ru(CO)2Cl2]n with one equivalent of [Ph2P(o-C6H4)CH=N(CH2)2N(CH3)2] (L2) led to the isolation of [Ru(CO)Cl2(κ3-P,N,N-L2)] (4). The molecular structures of the ruthenium(II) complexes 1–4 have been determined by single-crystal X-ray crystallography. The properties of the ruthenium(II) complex 4 as a hydrogenation catalyst for acetophenone were also tested.

Download Full-text

Exploring the Structural Chemistry of Pyrophosphoramides: N,N′,N″,N‴-Tetraisopropylpyrophosphoramide

Chemistry ◽

10.3390/chemistry3010013 ◽

2021 ◽

Vol 3 (1) ◽

pp. 149-163

Author(s):

Duncan Micallef ◽

Liana Vella-Zarb ◽

Ulrich Baisch

Keyword(s):

Crystal Structure ◽

Mass Spectrometry ◽

Nuclear Magnetic Resonance ◽

Hydrogen Bonding ◽

Nmr Spectroscopy ◽

Ir Spectroscopy ◽

Room Temperature ◽

Intermolecular Hydrogen Bonding ◽

X Ray Diffraction ◽

X Ray

N,N′,N″,N‴-Tetraisopropylpyrophosphoramide 1 is a pyrophosphoramide with documented butyrylcholinesterase inhibition, a property shared with the more widely studied octamethylphosphoramide (Schradan). Unlike Schradan, 1 is a solid at room temperature making it one of a few known pyrophosphoramide solids. The crystal structure of 1 was determined by single-crystal X-ray diffraction and compared with that of other previously described solid pyrophosphoramides. The pyrophosphoramide discussed in this study was synthesised by reacting iso-propyl amine with pyrophosphoryl tetrachloride under anhydrous conditions. A unique supramolecular motif was observed when compared with previously published pyrophosphoramide structures having two different intermolecular hydrogen bonding synthons. Furthermore, the potential of a wider variety of supramolecular structures in which similar pyrophosphoramides can crystallise was recognised. Proton (1H) and Phosphorus 31 (31P) Nuclear Magnetic Resonance (NMR) spectroscopy, infrared (IR) spectroscopy, mass spectrometry (MS) were carried out to complete the analysis of the compound.

Download Full-text

Silylated gallium and indium chalcogenide ring systems as potential precursors to ME (E=O, S) materials

Open Chemistry ◽

10.2478/s11532-013-0255-y ◽

2013 ◽

Vol 11 (7) ◽

pp. 1225-1238

Author(s):

Iliana Medina-Ramírez ◽

Cynthia Floyd ◽

Joel Mague ◽

Mark Fink

Keyword(s):

Thermal Decomposition ◽

Room Temperature ◽

Membered Ring ◽

Molecular Structures ◽

Nmr Studies ◽

X Ray ◽

X Ray Crystallography ◽

High Yields ◽

Vt Nmr ◽

State 1

AbstractThe reaction of R3M (M=Ga, In) with HESiR′3 (E=O, S; R′3=Ph3, iPr3, Et3, tBuMe2) leads to the formation of (Me2GaOSiPh3)2(1); (Me2GaOSitBuMe2)2(2); (Me2GaOSiEt3)2(3); (Me2InOSiPh3)2(4); (Me2InOSitBuMe2)2(5); (Me2InOSiEt3)2(6); (Me2GaSSiPh3)2(7); (Et2GaSSiPh3)2(8); (Me2GaSSiiPr3)2(9); (Et2GaSSiiPr3)2(10); (Me2InSSiPh3)3(11); (Me2InSSiiPr3)n(12), in high yields at room temperature. The compounds have been characterized by multinuclear NMR and in most cases by X-ray crystallography. The molecular structures of (1), (4), (7) and (8) have been determined. Compounds (3), (6) and (10) are liquids at room temperature. In the solid state, (1), (4), (7) and (9) are dimers with central core of the dimer being composed of a M2E2 four-membered ring. VT-NMR studies of (7) show facile redistribution between four- and six-membered rings in solution. The thermal decomposition of (1)–(12) was examined by TGA and range from 200 to 350°C. Bulk pyrolysis of (1) and (2) led to the formation of Ga2O3; (4) and (5) In metal; (7)–(10) GaS and (11)–(12) InS powders, respectively.

Download Full-text

Syntheses and crystal structures of guanidine hydrochlorides with two Schiff base functions as efficient colorimetric and selective sensors for fluoride

Zeitschrift für Naturforschung B ◽

10.1515/znb-2018-0102 ◽

2018 ◽

Vol 73 (8) ◽

pp. 601-609 ◽

Cited By ~ 1

Author(s):

Bei Wang ◽

Pei-Zhi Zhang ◽

Xin Chen ◽

Ai-Quan Jia ◽

Qian-Feng Zhang

Keyword(s):

Optical Properties ◽

Schiff Base ◽

Molecular Structures ◽

X Ray Diffraction ◽

Guanidinium Chloride ◽

Visible Absorption ◽

X Ray ◽

Color Changes ◽

Base Functions ◽

Magnetic Resonances

AbstractA series of guanidinium chloride derivatives have been synthesized by condensation of 1,3-diaminoguanidine monohydrochloride with heteroaromatic formaldehydes in good yields. All compounds were characterized by nuclear magnetic resonances and infrared spectroscopies, and the molecular structures of four compounds were determined by single crystal X-ray diffraction. The optical properties of these guanidinium chloride derivatives with fluoride anions were investigated, showing selective color changes from colorless to yellow or orange, red-shifted in the ultraviolet/visible absorption spectra.

Download Full-text

Doping of GaN by ion implantation

MRS Proceedings ◽

10.1557/proc-650-r8.4/o13.4 ◽

2000 ◽

Vol 650 ◽

Author(s):

Eduardo J. Alves ◽

C. Liu ◽

Maria F. da Silva ◽

José C. Soares ◽

Rosário Correia ◽

...

Keyword(s):

Optical Properties ◽

Ion Implantation ◽

Room Temperature ◽

Lattice Site ◽

Helium Temperature ◽

Site Location ◽

Structural And Optical Properties ◽

X Ray ◽

Er Doped ◽

Ion Implanted

ABSTRACTIn this work we report the structural and optical properties of ion implanted GaN. Potential acceptors such as Ca and Er were used as dopants. Ion implantation was carried out with the substrate at room temperature and 550 °C, respectively. The lattice site location of the dopants was studied by Rutherford backscattering/channeling combined with particle induced X-ray emission. Angular scans along both [0001] and [1011] directions show that 50% of the Er ions implanted at 550 oC occupy substitutional or near substitutional Ga sites after annealing. For Ca we found only a fraction of 30% located in displaced Ga sites along the [0001] direction. The optical properties of the ion implanted GaN films have been studied by photoluminescence measurements. Er- related luminescence near 1.54 μm is observed under below band gap excitation at liquid helium temperature. The spectra of the annealed samples consist of multiline structures with the sharpest lines found in GaN until now. The green and red emissions were also observed in the Er doped samples after annealing.

Download Full-text

The nature of the co-ordinate link. Part 11. Synthesis and phosphorus-31 nuclear magnetic resonance spectroscopy of platinum and palladium complexes containing side-bonded (E)-diphenyldiphosphene. X-Ray crystal and molecular structures of [Pd{(E)-PhPPPh}(Ph2PCH2CH2PPh2)] and [Pd{[(E)-PhPPPh][W(CO)5]2}(Ph2PCH2CH2PPh2)]

Journal of the Chemical Society Dalton Transactions ◽

10.1039/dt9840002237 ◽

1984 ◽

pp. 2237-2244 ◽

Cited By ~ 26

Author(s):

Joseph Chatt ◽

Peter B. Hitchcock ◽

Alan Pidcock ◽

Christopher P. Warrens ◽

Keith R. Dixon

Keyword(s):

Nuclear Magnetic Resonance ◽

Magnetic Resonance ◽

Magnetic Resonance Spectroscopy ◽

Nuclear Magnetic Resonance Spectroscopy ◽

Palladium Complexes ◽

Molecular Structures ◽

Resonance Spectroscopy ◽

X Ray ◽

Crystal And Molecular Structures ◽

Platinum And Palladium Complexes

Download Full-text

Doping of GaN by ion implantation

MRS Proceedings ◽

10.1557/proc-647-o13.4/r8.4 ◽

2000 ◽

Vol 647 ◽

Cited By ~ 1

Author(s):

Eduardo J. Alves ◽

C. Liu ◽

Maria F. da Silva ◽

José C. Soares ◽

Rosário Correia ◽

...

Keyword(s):

Optical Properties ◽

Ion Implantation ◽

Room Temperature ◽

Lattice Site ◽

Helium Temperature ◽

Site Location ◽

Structural And Optical Properties ◽

X Ray ◽

Er Doped ◽

Ion Implanted

AbstractIn this work we report the structural and optical properties of ion implanted GaN. Potential acceptors such as Ca and Er were used as dopants. Ion implantation was carried out with the substrate at room temperature and 550 °C, respectively. The lattice site location of the dopants was studied by Rutherford backscattering/channeling combined with particle induced X-ray emission. Angular scans along both [0001] and [1011] directions show that 50% of the Er ions implanted at 550 °C occupy substitutional or near substitutional Ga sites after annealing. For Ca we found only a fraction of 30% located in displaced Ga sites along the [0001] direction. The optical properties of the ion implanted GaN films have been studied by photoluminescence measurements. Er- related luminescence near 1.54 µm is observed under below band gap excitation at liquid helium temperature. The spectra of the annealed samples consist of multiline structures with the sharpest lines found in GaN until now. The green and red emissions were also observed in the Er doped samples after annealing.

Download Full-text

Electrical resistivity and photoluminescence of lead iodide crystals

Chemical Papers ◽

10.2478/s11696-006-0092-y ◽

2007 ◽

Vol 61 (1) ◽

Cited By ~ 8

Author(s):

M. Matuchová ◽

K. Žďánský ◽

M. Svatuška ◽

J. Zavadil ◽

O. Procházková

Keyword(s):

Electrical Resistivity ◽

Optical Properties ◽

Room Temperature ◽

Direct Synthesis ◽

Zone Melting ◽

Lead Iodide ◽

Electrical And Optical Properties ◽

X Ray ◽

Low Temperature Photoluminescence

AbstractDirect synthesis of lead iodide, a promising material for X-ray and γ detectors operating at room temperature, was developed and optimized. The influence of admixture of rare earth elements Ce, Ho, Gd, Yb, Er, and Tb in concentrations 0.05–0.5 at. % on the quality of prepared PbI2 was investigated. Zone melting was employed in order to increase the lead iodide purity. Electrical and optical properties of PbI2 samples were assessed on the basis of the measurement of electrical resistivity and low-temperature photoluminescence. The electrical resistivity of synthesized samples varied from 109 Ω cm to 1011 Ω cm and occasionally it was increased up to 1013 Ω cm.

Download Full-text

Growth and Magneto-Optical Properties of CaTbAlO4 Crystal

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.306-307.1722 ◽

2011 ◽

Vol 306-307 ◽

pp. 1722-1727 ◽

Cited By ~ 2

Author(s):

Man Mei ◽

Li Li Cao ◽

Yan He ◽

Ru Ru Zhang ◽

Fei Yun Guo ◽

...

Keyword(s):

Optical Properties ◽

Single Crystal ◽

Room Temperature ◽

Near Infrared ◽

Visible Region ◽

Czochralski Method ◽

Optical Devices ◽

X Ray Diffraction ◽

X Ray ◽

Infrared Spectral

The calcium terbium aluminate (CaTbAlO4) single crystal was grown by Czochralski method successfully for the first time.The structure of the crystal was determined by X-ray diffraction analysis.The transmission spectrum of the crystal was measured at room temperature at the wavelength of 400-1500nm.The specific Faraday rotation of the single crystal was surveyed at room temperature at the wavelength 532nm, 633nm, and 1064nm respectively.The Verdet constants of the CaTbAlO4 crystal are calculated and the results show that the Verdet constants of CaTbAlO4 are around 110% higher than that of TGG in the visible and near-infrared spectral region.Therefore,crystal CaTbAlO4 can be promising material for the fabrication of magneto-optical devices in the visible region.

Download Full-text

Impact of Nitridation on Structural and Optical Properties of Epitaxial GaN Films Grown on M-Plane Sapphire by PAMBE

MRS Proceedings ◽

10.1557/opl.2015.104 ◽

2015 ◽

Vol 1736 ◽

Cited By ~ 1

Author(s):

Shruti Mukundan ◽

Lokesh Mohan ◽

Greeshma Chandan ◽

Basanta Roul ◽

S.B. Krupanidhi

Keyword(s):

Optical Properties ◽

Room Temperature ◽

Compressive Strain ◽

Structural And Optical Properties ◽

X Ray ◽

Force Microscopy ◽

Atomic Force ◽

Semipolar Gan ◽

Nonpolar Gan ◽

Gan Film

ABSTRACTGaN epilayers were grown on m-plane (10-10) sapphire substrates using plasma assisted molecular beam epitaxy. Impact of nitridation on structural and optical properties of GaN film was investigated. The film grown on a nitridated surface resulted in a nonpolar (10-10) orientation while without nitridation caused a semipolar (11-22) orientation. The high resolution X-ray diffraction studies confirmed the orientation of the GaN films. X-ray rocking curve showed better crystallinity of semipolar as compared to nonpolar GaN. Atomic force microscopy showed smoother films in case of nonpolar GaN which might be in account of the nitridation treatment. Room temperature photoluminescence study showed nonpolar GaN to have higher value of compressive strain as compared to semipolar GaN film, which was further confirmed by room temperature Raman spectroscopy. Despite the fact that it is difficult to obtain high-quality nonpolar material due to the planar anisotropic nature of the growth mode, we hereby report the development of non-polar GaN of usable quality, on an m-plane sapphire, involving controlled steps of nitridation.

Download Full-text