scholarly journals Monovalent lanthanide(I) in borozene complexes

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Wan-Lu Li ◽  
Teng-Teng Chen ◽  
Wei-Jia Chen ◽  
Jun Li ◽  
Lai-Sheng Wang
Keyword(s):  
Magnetic Properties ◽  
Oxidation State ◽  
Photoelectron Spectroscopy ◽  
Global Minimum ◽  
Theoretical Calculations ◽  
Oxidation States ◽  
State Change ◽  
Boron Clusters ◽  
Aromatic Ligand ◽  
Hydrocarbon Molecules

AbstractLanthanide (Ln) elements are generally found in the oxidation state +II or +III, and a few examples of +IV and +V compounds have also been reported. In contrast, monovalent Ln(+I) complexes remain scarce. Here we combine photoelectron spectroscopy and theoretical calculations to study Ln-doped octa-boron clusters (LnB8−, Ln = La, Pr, Tb, Tm, Yb) with the rare +I oxidation state. The global minimum of the LnB8− species changes from Cs to C7v symmetry accompanied by an oxidation-state change from +III to +I from the early to late lanthanides. All the C7v-LnB8− clusters can be viewed as a monovalent Ln(I) coordinated by a η8-B82− doubly aromatic ligand. The B73−, B82−, and B9− series of aromatic boron clusters are analogous to the classical aromatic hydrocarbon molecules, C5H5−, C6H6, and C7H7+, respectively, with similar trends of size and charge state and they are named collectively as “borozenes”. Lanthanides with variable oxidation states and magnetic properties may be formed with different borozenes.

Probing the structures and bonding of size-selected boron and doped-boron clusters

2019 ◽  
Vol 48 (13) ◽  
pp. 3550-3591 ◽  
Author(s):  
Tian Jian ◽  
Xuenian Chen ◽  
Si-Dian Li ◽  
Alexander I. Boldyrev ◽  
Jun Li ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Theoretical Calculations ◽  
Boron Clusters

Photoelectron spectroscopy in conjunction with theoretical calculations has been used to investigate size-selected boron clusters, uncovering interesting structures and bonding.

scholarly journals Single crystal structures and theoretical calculations of uranium endohedral metallofullerenes (U@C2n, 2n = 74, 82) show cage isomer dependent oxidation states for U

2017 ◽  
Vol 8 (8) ◽  
pp. 5282-5290 ◽  
Author(s):  
Wenting Cai ◽  
Roser Morales-Martínez ◽  
Xingxing Zhang ◽  
Daniel Najera ◽  
Elkin L. Romero ◽  
...  
Keyword(s):  
Single Crystal ◽  
Crystal Structures ◽  
Oxidation State ◽  
Theoretical Calculations ◽  
State Dependence ◽  
Oxidation States ◽  
Metal Oxidation ◽  
X Ray ◽  
Endohedral Metallofullerenes ◽  
Single Crystal Structures

First X-ray structures and metal oxidation state dependence on cage isomerism for U-EMFs.

B48−: a bilayer boron cluster

Nanoscale ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 3868-3876
Author(s):  
Wei-Jia Chen ◽  
Yuan-Yuan Ma ◽  
Teng-Teng Chen ◽  
Mei-Zhen Ao ◽  
Dao-Fu Yuan ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Global Minimum ◽  
Theoretical Calculations ◽  
Bilayer Structure ◽  
Boron Cluster

Photoelectron spectroscopy and theoretical calculations show that the global minimum of the B48− cluster has a bilayer structure, suggesting the viability of bilayer borophenes.

Mn Oxidation States in Bax CsyMnzTi8-zO16

2004 ◽  
Vol 824 ◽  
Author(s):  
M.L. Carter ◽  
E.R. Vance ◽  
D. R. G. Mitchell ◽  
Z. Zhang
Keyword(s):  
Energy Loss ◽  
Absorption Spectra ◽  
Electron Energy ◽  
Oxidation State ◽  
Electron Energy Loss Spectroscopy ◽  
Photoelectron Spectroscopy ◽  
Oxidation States ◽  
X Ray ◽  
Electron Energy Loss ◽  
X Ray Absorption

AbstractTwo Bax CsyMnzTi8-zO16 hollandite samples, containing excess rutile, have been prepared, targeting the Mn valence as 3+ by sintering at 1300oC in air (z = 2x +y) and as 2+ (z = x + y/2) in argon. SEM showed the sample sintered in air to contain major hollandite and minor Mn titanate and rutile. The sample sintered in argon contain major hollandite, and minor Ba titanate and rutile. X-ray absorption near edge spectroscopy (XANES), electron energy loss spectroscopy (EELS) and X-ray photoelectron spectroscopy (XPS) were used to determine the oxidation state of the Mn in the samples. Transmission manganese K-edge X-ray absorption spectra of the samples were similar but the precise ratio of oxidation states could not be calculated from these spectra.

Evaluation and X-Ray Induced Modification of the Cerium Oxidation State in Cerium Calixarene Complexes

2007 ◽  
Vol 128 ◽  
pp. 115-120 ◽  
Author(s):  
Yuri Suchorski ◽  
Jochen Gottfriedsen ◽  
Rafal Wrobel ◽  
Bartosz Strzelczyk ◽  
Helmut Weiss
Keyword(s):  
Oxidation State ◽  
Photoelectron Spectroscopy ◽  
Fine Tuning ◽  
Oxidation States ◽  
Ambient Conditions ◽  
X Ray ◽  
New Class ◽  
Oxidative Transformations

The cerium oxidation state in novel calixarene-supported cerium(IV) β-diketonate complexes [p-tBu-calix[4](OMe)2(O)2]Ce(acac)2 (1) and [p-tBu-calix[4](OMe)2(O)2]Ce(hfac)2 (2), which are a new class of potential precursors for homogeneous oxidative transformations, has been determined using X-ray photoelectron spectroscopy (XPS). Cerium oxidation states between 3.6 and 3.65 were detected, distinctly different from their nominal value of +4. An X-ray induced photoreduction of these compounds was detected. Because of the observed stability of the X-ray modified oxidation state under ambient conditions this effect might be used for a long-standing fine tuning of the Ce oxidation state in cerium calixarenes.

scholarly journals SYNTHESIS AND STUDY OF RHENIUM(IV) DISULPHIDE

2017 ◽  
Vol 12 (6) ◽  
pp. 83-90
Author(s):  
A. M. Ionov ◽  
M. R. Kobrin ◽  
R. N. Mozhchil ◽  
A. S. Sigov ◽  
Yu. V. Syrov ◽  
...  
Keyword(s):  
Oxidation State ◽  
Communication Technology ◽  
Photoelectron Spectroscopy ◽  
Condensed Matter ◽  
Optoelectronic Devices ◽  
Structural Type ◽  
Oxidation States ◽  
Ir Absorption ◽  
Transition Elements ◽  
X Ray

Synthesis and study of complex chalcogenides in the low oxidation state opens unexpected new opportunities of studying some fundamental problems of condensed matter physics. Dichalcogenides of transition metals, i.e., compounds with the general formula MX2, where M is molybdenum, tungsten, rhenium etc., and X is sulphur, selenium or tellurium, are especially interesting. These dichalcogenides find applications in optoelectronic devices, radiophotonics, in laser physics, communication technology, etc. This study contains a survey of literature concerning the synthesis of sulphides of transition elements from different groups of the Periodic table in low oxidation states. A method of direct hightemperature synthesis of ReS2 from source components has been proposed and implemented. The synthesized compound was identified by the X-ray fluorescence, method of photoelectron spectroscopy and IR absorption spectroscopy. We show that rhenium(IV) disulphide crystallizes in CdI2 structural type. X-ray photoelectron spectroscopy shows that rhenium in the oxidation state of four is present. IR spectrum shows that rhenium(IV) disulphide structure in contrast to molybdenum(IV) disulphide is characterized by a greater deformation of the layers forming the crystal structure.

scholarly journals Effects of Perpendicular Magnetic Field Annealing on the Structural and Magnetic Properties of [Co/Ni]2/PtMn Thin Films

2021 ◽  
Vol 7 (3) ◽  
pp. 38
Author(s):  
Roshni Yadav ◽  
Chun-Hsien Wu ◽  
I-Fen Huang ◽  
Xu Li ◽  
Te-Ho Wu ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Thin Films ◽  
Magnetic Properties ◽  
Photoelectron Spectroscopy ◽  
Perpendicular Magnetic Field ◽  
Face Centered Cubic ◽  
Lattice Image ◽  
X Ray ◽  
Field Annealing ◽  
Face Centered

In this study, [Co/Ni]2/PtMn thin films with different PtMn thicknesses (2.7 to 32.4 nm) were prepared on Si/SiO2 substrates. The post-deposition perpendicular magnetic field annealing (MFA) processes were carried out to modify the structures and magnetic properties. The MFA process also induced strong interlayer diffusion, rendering a less sharp interface between Co and Ni and PtMn layers. The transmission electron microscopy (TEM) lattice image analysis has shown that the films consisted of face-centered tetragonal (fct) PtMn (ordered by MFA), body-centered cubic (bcc) NiMn (due to intermixing), in addition to face-centered cubic (fcc) Co, Ni, and PtMn phases. The peak shift (2-theta from 39.9° to 40.3°) in X-ray diffraction spectra also confirmed the structural transition from fcc PtMn to fct PtMn after MFA, in agreement with those obtained by lattice images in TEM. The interdiffusion induced by MFA was also evidenced by the depth profile of X-ray photoelectron spectroscopy (XPS). Further, the magnetic properties measured by vibrating sample magnetometry (VSM) have shown an increased coercivity in MFA-treated samples. This is attributed to the presence of ordered fct PtMn, and NiMn phases exchange coupled to the ferromagnetic [Co/Ni]2 layers. The vertical shift (Mshift = −0.03 memu) of the hysteresis loops is ascribed to the pinned spins resulting from perpendicular MFA processes.

Mixed Metal Oxide Interfaces: An Experimental and Theoretical Assessment of Secondary Metal Influences in Metal Impregnated Aluminas

1994 ◽  
Vol 368 ◽  
Author(s):  
M. Malaty ◽  
D. Singh ◽  
R. Schaeffer ◽  
S. Jansen ◽  
S. Lawrence
Keyword(s):  
Photoelectron Spectroscopy ◽  
Theoretical Calculations ◽  
Mixed Metal Oxide ◽  
X Ray Diffraction ◽  
Paramagnetic Resonance ◽  
X Ray ◽  
Mixed Metal ◽  
Metal Interactions ◽  
Metal Metal ◽  
Bimetallic System

ABSTRACTStudies of the mixed-metal interface in metal impregnated alumina have indicated the possibility of much metal-metal and metal-substrate interaction. Studies were carried out on NiCu/Al2O3 system which was evaluated to develop a better understanding of the forces that drive modification of the catalytic selectivity of Ni in the presence of Cu. Electron Paramagnetic Resonance (EPR), Powder X-ray Photoelectron Spectroscopy (XPS), X-ray Diffraction (XRD) and theoretical calculations were carried out on this bimetallic system, using Ni,Ag/Al2O3 as a reference as Ni shows negligible electron perturbation on co-adsorbance with Ag onto alumina. XRD results indicate that gross modification of the electronic fields of Ni and Cu are due to direct coupling and intercalation into the alumina matrix. As a result of this phenomena, these materials may form a good base for the development of novel ceramics based on mixed-metal interactions where the intermetallic perturbations are driven by the substrate effects.

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