Interplay between point symmetry, oxidation state, and the Kondo effect in 
3d
 transition metal acetylacetonate molecules on Cu(111)

Aim and Objective: The synthesis of bipyridines, especially 2, 2’-bipyridines, remains challenging because the catalytic cycle can be inhibited due to coordination of bipyridine to transition metal. Thus, the development of efficient methods for the synthesis of bipyridines is highly desirable. In the present work, we presented a promising approach for preparation of bipyridines via a Pd-catalyzed reductive homocoupling reaction with simple piperazine as a ligand. Materials and Methods: Simple and inexpensive piperazine was used as a ligand for Pd-catalyzed homocoupling reaction. The combination of Pd(OAc)2 and piperazine in dimethylformamide (DMF) was observed to form an excellent catalyst and efficiently catalyzed the homocoupling of azaarenyl halides, in which DMF was used as the solvent without excess reductants although stoichiometric reductant was generally required to generate the low-oxidation-state active metal species in the catalytic cycles. </P><P> Results: In this case, good to excellent yields of bipyridines and their (hetero) aromatic analogues were obtained in the presence of 2.5 mol% of Pd(OAc)2 and 5 mol% of piperazine, using K3PO4 as a base in DMF at 140°C. Conclusion: According to the results, piperazine as an inexpensive and efficient ligand was used in the Pd(OAc)2-catalyzed homocoupling reaction of heteroaryl and aryl halides. The coupling reaction was operationally simple and displayed good substrate compatibility.

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Weak Kondo effect in the monocrystalline transition metal dichalcogenide ZrTe2

Physical Review B ◽

10.1103/physrevb.103.174418 ◽

2021 ◽

Vol 103 (17) ◽

Author(s):

Yihao Wang ◽

Changzheng Xie ◽

Junbo Li ◽

Zan Du ◽

Liang Cao ◽

...

Keyword(s):

Transition Metal ◽

Kondo Effect ◽

Transition Metal Dichalcogenide

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Transition metal chemistry in synthetically viable alkaline earth complexes M(Cp)3– (M = Ca, Sr, Ba)

Chemical Communications ◽

10.1039/d1cc01753e ◽

2021 ◽

Author(s):

Bin Huo ◽

Rui Sun ◽

Bo Jin ◽

Lingfei Hu ◽

Jian-Hong Bian ◽

...

Keyword(s):

Transition Metal ◽

Oxidation State ◽

Alkaline Earth ◽

Transition Metal Chemistry ◽

Metal Chemistry

We predicted the stable alkaline earth complexes M(Cp)3– (M = Ca, Sr, Ba; Cp = cyclopentadienyl), where the M centers were in their stable +2 oxidation state and mimicked the...

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Bonding and Oxidation State of a Transition Metal Atom Encapsulated in an Isolated Octahedral Cluster Cation of Main Group Elements: Synthesis, Crystal Structure, and Electronic Structure of Pt2In14Ga3O8F15 Containing Highly Positive 18-Electron Complex [PtIn6]10+ and Low-Valent In+ Ions.

ChemInform ◽

10.1002/chin.200521027 ◽

2005 ◽

Vol 36 (21) ◽

Author(s):

Juergen Koehler ◽

Jen-Hui Chang ◽

Myung-Hwan Whangbo

Keyword(s):

Crystal Structure ◽

Electronic Structure ◽

Transition Metal ◽

Oxidation State ◽

Metal Atom ◽

Main Group ◽

Transition Metal Atom ◽

Octahedral Cluster ◽

Main Group Elements ◽

Cluster Cation

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5439829 Immobilization of biologically active molecules by changing the oxidation state of a chelated transition metal ion

Biotechnology Advances ◽

10.1016/s0734-9750(97)81746-6 ◽

1996 ◽

Vol 14 (4) ◽

pp. 510

Keyword(s):

Transition Metal ◽

Oxidation State ◽

Metal Ion ◽

Biologically Active ◽

Transition Metal Ion

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Femtosecond M2,3-Edge Spectroscopy of Transition-Metal Oxides: Photoinduced Oxidation State Change in α-Fe2O3

The Journal of Physical Chemistry Letters ◽

10.1021/jz401997d ◽

2013 ◽

Vol 4 (21) ◽

pp. 3667-3671 ◽

Cited By ~ 71

Author(s):

Josh Vura-Weis ◽

Chang-Ming Jiang ◽

Chong Liu ◽

Hanwei Gao ◽

J. Matthew Lucas ◽

...

Keyword(s):

Transition Metal ◽

Metal Oxides ◽

Oxidation State ◽

Transition Metal Oxides ◽

State Change

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Synthesis and characterisation of transition metal substituted barium hollandite ceramics

MRS Proceedings ◽

10.1557/proc-932-60.1 ◽

2006 ◽

Vol 932 ◽

Cited By ~ 2

Author(s):

Neil C. Hyatt ◽

Martin C. Stennett ◽

Steven G. Fiddy ◽

Jayne S. Wellings ◽

Sian S. Dutton ◽

...

Keyword(s):

Transition Metal ◽

Oxidation State ◽

Powder Diffraction ◽

Single Phase ◽

Maximum Density ◽

Processing Conditions ◽

Metal Oxidation ◽

Exafs Data ◽

X Ray ◽

Oxygen Atoms

ABSTRACTA range of transition metal bearing hollandite phases, formulated Ba1.2B1.2Ti6.8O16 (B2+ = Mg, Co, Ni, Zn, Mn) and Ba1.2B2.4Ti5.6O16 (B3+ = Al, Cr, Fe) were prepared using an alkoxide - nitrate route. X-ray powder diffraction demonstrated the synthesis of single phase materials for all compositions except B = Mn. The processing conditions required to produce > 95 % dense ceramics were determined for all compositions, except B = Mg for which the maximum density obtained was > 93 %. Analysis of transition metal K-edge XANES data confirmed the presence of the targeted transition metal oxidation state for all compositions except B = Mn, where the overall oxidation state was found to be Mn3+. The K-edge EXAFS data of Ba1.2B1.2Ti6.8O16 (B = Ni and Co) were successfully analysed using a crystallographic model of the hollandite structure, with six oxygen atoms present in the first co-ordination shell at a distance of ca. 2.02Å. Analysis of Fe K-edge EXAFS data of Ba1.2B2.4Ti5.4O16 revealed a reduced co-ordination shell of five oxygens at ca. 1.99Å.

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