scholarly journals Construction of Highly Reactive Silanimine- and Phosphasilene-coordinated Complexes Composed of Silicon, Group 15 Elements, and Transition Metals

2021 ◽  
Vol 78 (0) ◽  
pp. 18-35
Author(s):  
Masaaki Okazaki
Keyword(s):  
Transition Metals ◽  
Group 15

Carbonyl Halides of the Group 6 Transition Metals. XXVIII. Phosphorus-31 and Selenium-77 N.M.R. Studies of Some Selenium-Group 15 Donor Complexes

1987 ◽  
Vol 40 (1) ◽  
pp. 13 ◽  
Author(s):  
R Colton ◽  
P Panagiotidou
Keyword(s):  
Transition Metals ◽  
Silver Nitrate ◽  
The Other ◽  
Donor Atom ◽  
Monodentate Ligand ◽  
Quantitative Formation ◽  
Other Hand ◽  
Group 6 ◽  
Group 15

The ligands Ph2PCH2P(Se)Ph2 ( dpmSe ) and Ph2AsCH2CH2P(Se)Ph2 ( apeSe ) have been treated with Group 6 metal pentacarbonyl halo anions, [M(C0)5X]-, the Group 6 hexacarbonyls and the carbonyl halides M(C0)4X2 (M = Mo, W, X = C1, Br). Reaction of both dpmSe and apeSe with the anions [M(C0)5X]- in the presence of silver nitrate gave the complexes M(CO)5(L-L′) (L-L′ = dpmSe or apeSe ) with the ligand coordinated in a monodentate fashion through the Group 15 donor atom. Reaction of dpmSe with the hexacarbonyls gave only M(C0)4( dpmSe ) with the ligand chelated but, in contrast, apeSe could not be chelated to metal(0) and acted only as a monodentate ligand. These differences are rationalized in terms of the structure of the ligands. The behaviour of the ligands is much more similar in the metal(11) carbonyl halide chemistry. Both formed a mixture of two isomers of M(CO)3(L-L′)X2 (L-L′= dpmSe, apeSe ) in which the ligands are chelated . In the apeSe system, n.m.r. studies show these isomers are in an equilibrium which varies with temperature at a rate which is slow on the n.m.r. timescale, but the dpmSe complexes do not interchange. On reaction with further ligand, only one of the isomers of M(CO)3( dpmSe )X2 reacts to give incomplete formation of the dicarbonyl Mo(Co)2( dpmSe )2X2, which has one dpmSe ligand chelated and the other monodentate through phosphorus. On the other hand, for the apeSe system quantitative formation of Mo(CO)2( apeSe )2X2 was observed. For the apeSe system only, bubbling CO through a solution of M(CO)2( apeSe )2X2 gave M(CO)3( apeSe )2X2 with the ligands monodentate through arsenic. Extensive 31P and 77Se n.m.r. studies are described.

Precipitation in silicon: Microanalysis

1988 ◽  
Vol 46 ◽  
pp. 474-475
Author(s):  
R.W. Carpenter
Keyword(s):  
Transition Metals ◽  
Spatial Resolution ◽  
Thin Foil ◽  
Precipitation Reaction ◽  
High Current ◽  
Reaction Products ◽  
Carbon And Nitrogen ◽  
Dielectric Layers ◽  
Precipitation Processes ◽  
Areas Of Interest

Interest in precipitation processes in silicon appears to be centered on transition metals (for intrinsic and extrinsic gettering), and oxygen and carbon in thermally aged materials, and on oxygen, carbon, and nitrogen in ion implanted materials to form buried dielectric layers. A steadily increasing number of applications of microanalysis to these problems are appearing. but still far less than the number of imaging/diffraction investigations. Microanalysis applications appear to be paced by instrumentation development. The precipitation reaction products are small and the presence of carbon is often an important consideration. Small high current probes are important and cryogenic specimen holders are required for consistent suppression of contamination buildup on specimen areas of interest. Focussed probes useful for microanalysis should be in the range of 0.1 to 1nA, and estimates of spatial resolution to be expected for thin foil specimens can be made from the curves shown in Fig. 1.

MAGNETIC STUDIES OF Clb-COMPOUNDS OF TRANSITION METALS

1971 ◽  
Vol 32 (C1) ◽  
pp. C1-74-C1-75 ◽  
Author(s):  
K. ENDO ◽  
Y. FUJITA ◽  
R. KIMURA ◽  
T. OHOYAMA ◽  
M. TERADA
Keyword(s):  
Transition Metals ◽  
Magnetic Studies
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