ChemInform Abstract: MODELING CATALYTIC REACTIONS WITH TRANSITION METAL ATOMS. 1. SYNTHESIS AND CHARACTERIZATION OF REACTIVE INTERMEDIATES IN THE NICKEL-ETHYLENE SYSTEM, (C2H4)NNI (WHERE N = 1, 2, OR 3) IN LOW TEMPERATURE MATRICES

1976 ◽  
Vol 7 (52) ◽  
pp. no-no
Author(s):  
H. HUBER ◽  
G. A. OZIN ◽  
W. J. POWER
Keyword(s):  
Low Temperature ◽  
Transition Metal ◽  
Reactive Intermediates ◽  
Catalytic Reactions ◽  
Synthesis And Characterization ◽  
Metal Atoms ◽  
Transition Metal Atoms

Synthesis of New Chiral Crown Ethers Containing Phosphine or Secondary Phosphine Oxide Units

Synthesis ◽  
2020 ◽  
Vol 52 (19) ◽  
pp. 2870-2882
Author(s):  
Péter Huszthy ◽  
Hajnalka Szabó-Szentjóbi ◽  
István Majoros ◽  
Anna Márton ◽  
Ibolya Leveles ◽  
...  
Keyword(s):  
Transition Metal ◽  
Crown Ethers ◽  
Transition Metal Complexes ◽  
Phosphine Oxide ◽  
Catalytic Reactions ◽  
Synthesis And Characterization ◽  
Secondary Phosphine ◽  
Trivalent Phosphorus ◽  
Chiral Crown Ethers

The transition-metal complexes of phosphine and secondary phosphine oxide compounds can be used in various catalytic reactions. In this paper, the synthesis and characterization of eight new crown ethers containing trivalent phosphorus in their macroring are reported. These macrocycles are promising candidates as ligands for catalytic reactions.

Étude magnétique des matériaux de type Ln2M12P7 (Ln = Ce, Sm, Gd et Er; M = Co et Fe)

2000 ◽  
Vol 78 (2) ◽  
pp. 153-159
Author(s):  
J Dhahri ◽  
N Fourati ◽  
E Dhahri
Keyword(s):  
Magnetic Susceptibility ◽  
Low Temperature ◽  
Transition Metal ◽  
Constant Field ◽  
Free Ions ◽  
Metal Atoms ◽  
Transition Metal Atoms ◽  
Saturation Moment ◽  
Zero Moment ◽  
Good Agreement

A magnetic study has been undertaken on the substances of formula Ln2M12X7. The magnetic susceptibility and the magnetization have been measured as a function of temperature for a constant field. The magnetic susceptibility measurements have been performed from ambient temperature up to 1000 K. The effective paramagnetic moments were deduced from 1 / χ = f(T) curves, assuming a zero moment on the transition metal atoms. It is shown that these values are in good agreement with the theoretical values calculated for the free ions Ln3+. The saturation moment and the paramagnetic Curie temperature values show an antiferromagnetic behavior for Ce2Co12P7 at low temperature. The magnetic moment of Sm2Co12P7 measured at 4.2 and 78 K under a 2.66 T magnetic field shows a complex magnetic structure at low temperature. Our work on these materials show that the magnetic properties of Ln2M12X7 could be interpreted from previous studies on the phases rare earth – transition metal Ln–M.

The First Tetrahedrally Bonded Diamond–Like Compounds with Metallic Conductivity

1985 ◽  
Vol 49 ◽  
Author(s):  
Y. Sawan
Keyword(s):  
Transition Metal ◽  
Valence Electron Concentration ◽  
Metallic Conductivity ◽  
Metal Atoms ◽  
Transition Metal Atoms ◽  
Tetrahedral Environment ◽  
Formal Charge ◽  
First Time ◽  
Tetrahedrally Bonded

AbstractIn this paper we report for the first time the discovery of metallic conductivity in some tetrahedrally bonded diamond–like ternary oompounds 1 v vl with the general formula A3B C4 · Such compounds are characterized by a Valence Electron Concentration (VEC) of four valence electrons per atom. The preparation and characterization of one of the investigated compounds Cu3AsSe4 will be presented.The transition metal atoms in such a compound are connected by non-transition metal atoms (Se) via coordinate locallized bonds in a tetrahedral environment. Such an environment should lead to a splitting in the 3d filled orbitals of the transition metal because of lattice field. A delocalization of the 3d electrons is expected to take place via back donation, through an overlap with the empty antibonding orbitals on the non-metal atoms to minimize the negative formal charge on the transition metal atoms. If such an overlap leads to continuous electron path through the whole material, metallic conductivity could be visualized. The detailed bonding model will be discussed.

Sign in / Sign up

Export Citation Format

Share Document