A NOVEL SYNTHETIC METHOD AND STRUCTURE OF TETRAKIS(BENZOATE)BIS(TRIPHENYLPHOSPHINE OXIDE)DICOPPER(II).OXIDATIVE ADDITION OF DIBENZOYL ON METALLIC COPPER

Dibenzoyl peroxide undergoes oxidative addition on metallic copper with triphenylphosphine in a mixed solvent(acetone,dichloromethane and trichloromethane),and affords the binuclear copper complex (Cu(C_6H_5COO)_2(OPPh_3))_2.Crystals are monoclinic,space group A_2/a,with cell parameters,a=24.337(3),b=10.566(1),c=21.579(2),β= 93.18(1)°, V=5540(1)~3,Z=4,R=0.042,and Rw=0.044 for 5872 observed reflections. Each copper ion is coordinated by four bridging benzoato ligands and one triphenylphosphine oxide group to form binuclear complexes.

SYNTHESIS AND STRUCTURE OF Cu(Ⅱ)COMPLEXES BY OXIDATIVE ADDITION OF DIBENZOYL PEROXIDE ON METALLIC COPPER

Dibenzoyl peroxide undergoes oxidative addition on metallic copper powder with 2,2′-bipyridine(or imidazole)in a mixed solvent(methanol and tetrahydrofuran),and affords the Cu(Ⅱ)complexes-[Cu(Ce(C_6H_5COO)_2(2,2'-bipy)]H_2O(1) and[Cu(C_6H_5COO)_2(C_3H_4N_2)_2](2).The structure was solved by direct methods and Fourier synthesis.C_(24)H_(20)N_2O_5Cu (1),Mr=479.78,space group P2(1)/c,a=6.986(7), b=18.833(I),c=17.021(3),α=γ=90°,Z=4,V=2218.1~3,Dc=1.443g/cm\+3,R=0.055 Rw=0.062.Complex(2),C_(20)H_(18)N_4O_4Cu(2),Mr=441.74,space group P2(1)/n,a=8.699(4), b=9.840(6),c=12.399(5),α=γ=90°,β=100.8°,Z=4,V=1010.9~3,Dc=1.654g/cm\+3,R=0.055, Rw=0.062.

Design of high-performance molybdenum alloys via doping metal oxide and carbide strengthening:A review

Metal oxide and carbide strengthening molybdenum(Mo)alloys have been designed as promising ad-vanced materials in refractory metals to solve some of the core engineering problems in superalloy ap-plications.Hence,there is a need to summarize the results obtained and evaluate the opportunities for preparing high-performance Mo alloys by strengthening metal oxides and carbides to improve the per-formance characteristics of Mo metal materials.This paper reviews the results of the reported work con-cerning the structure and properties of Mo alloys with different metal oxide and carbide strengthening methods added to Mo matrix.The influence of the doping of La 2 O 3 and Y 2 O 3 particles,ceramic Al 2 O 3 and ZrO 2 particles,and refractory TiC and ZrC carbides particles of Mo alloys are discussed.The impacts of particle morphology,size,distribution and volume fractions of oxide and carbide are analyzed,as well as the specific features of different doping techniques for obtaining high-performance Mo alloys mate-rials.This work will guide future research on the design of high-performance refractory Mo alloys by adding oxides and carbide particles,helping to solve the core issues in the field of superalloy application research.

Review on Enhancement of Nitridation of Si Powder

This paper reviewed the effect of powder characteristics and additives including metals,rare earth oxides,and ZrO2 on nitridation of Si powder.The decrease of particle size of Si powder increased nitridation.Most of metal additives inhibited nitridation,while some metal additives such as Fe,Cu,Cr,and Ca increased nitrida—tion.Otherwise,the addition of metals might lead to the degradation of physical and mechanical properties of Si3N4.All the rare earth oxides,especially CeO2 and Eu2O3,showed nitridation enhancing effect.In addition,ZrO2 with small particle size showed a stronger enhancing effect.