Alignment of double vacancy states (1s2p)−1 3 P and1 P of neon for electron impact ionization

From intensity of Auger transitions (1s2p)^{?1 1} P,³ P→2p ^{?3 2} P,² D+e _A ^? relative to 1s ^{?1 2} S→2p ^{?2 1} D+e _A ^? measured at ?=54 and 90° relative to the primary electron beam we have determined the alignment of double vacancy states (1s 2p)^{?1 1} P and³ P of neon for electron impact ionization for the impact energies 1.5, 2.0, 2.5 and 4.0 keV. ForE ₀=1.5, 2.0 and 2.5 keV the alignment is compatible with zero with an upper limit of , forE ₀=4.0 keV a small negative value was found.     

The Reactions of 1-Acetothiosemicarbazidc with P(NR_2)_3 PC1_3 and PCI_5

A Series of new heterocyciophosphorus compounds were synthesizec oy cyclocondensa-tion of 1-acetothiosemicarbazide with P(NR2)3. The further reaction of these compounds with P(NR2)3 gave different compounds depending upon different reaction conditions. The 1-acetothiosemicarbazide can also condense with PCl3 and PCl5 similarly, The reaction mechanism, the spectral properties and chemical properties of these products were also studied and discussed.     

He(23S1)、Ne(3P0,2)与NH3的传能动力学

在分子束条件下利用化学发光技术研究了亚稳态惰性气体原子He（23S1）和Ne（3P0，2）与NH3碰撞的解离激发反应．He（23S1）与NH3的反应中观察到NH（A－X，c－a，c－b），NH＋（B－X）和H*－Balmer发射．对NH（A－X，c－a）的谱图进行了拟合．分析NH（c－b）谱发现NH（c）倾向于生成具有f对称性的转动能级，NH3可能是经由一个NH2中间体分两步解离，这与121．6nm光解NH3时的倾向性正好相反．利用参比反应测得生成NH（A，c）的速度为k＝1．0×10－11cm3•s－1．He（23S1）与NH3生成的NH（A，v’＝1）的转动激发比v’＝0时要高，根据含角动量守恒的相空间理论，其生成过程可能具有较大的解离半碰撞参数．Ne（3P0，2）与NH3反应只有NH（A－X，c－a）发射，NH（A，c）的振转布居可由简单相空间理论三体解离模式解释．     

1, 3-双磷(膦)酰基丙烯类化合物的^1H、^3^1P NMR研究

本文报道了标题类化合物中十个化合物的^1H和^3^1PNMR的研究结果。其中分别运用了2DJ分解谱以及异核COSY谱等多种技术,解析了它们的^1H和^3^1P图谱,从而证实了合成反应的区域选择性和立体选择性。文章中,讨论了手性中心或其它因素而表现出的不等性;讨论了影响δ~P和J~p~H数值的各种因素:还报道了比较少见的^3^1P-^3^1P之间的远程偶合。其中,顺式产物的^4J~P~P数值(约9Hz)大于反式产物的^4J~P~P(约7Hz)。     

1, 3-双磷(膦)酰基丙烯类化合物的^1H、^3^1P NMR研究

本文报道了标题类化合物中十个化合物的~1H和~(31)P NMR的研究结果.其中分别运用了2DJ分解谱以及异核COSY谱等多种技术,解析了它们的~1H和~(31)P图谱,从而证实了合成反应的区域选择性和立体选择性.文章中,讨论了因手性中心或其它因素而表现出的不等性;讨论了影响δ_p和J_(PH)数值的各种因素:还报道了比较少见的~(31)P-~(31)P之间的远程偶合.其中,顺式产物的~4J_(pp)数值(约9 Hz)大于反式产物的~4J_(pp)(约7 Hz).     

磷酸三甲(丁)酯质子化的^3^1P和1HNMR研究

测量了与水无限混溶的磷酸三甲酯(TMP)质子化过程的^3^1P化学位移的变化,解析后得到H2O.TMP(H.M)和H2O.2TMP(H.2M)两配合物的平衡常数,用^1H NMR研究混合物中水的化学位移,找出了自由水^1H化学位移值与浓度的关系,并在TBP体系中进行验证.     

SiH3+O(3P)反应机理的理论研究

The reaction for SiH3+O(3P) was studied by ab initio method. The geometries of the reactants, intermediates, transition states and products were optimized at MP2/6-311+G(d,p) level. The single point calculations for all the stationary points were carried out at the QCISD(T) /6-311+G(d,p) level using the MP2/6-311+G(d,p) optimized geometries. The results of the theoretical study indicate that the major pathway is the SiH3+O(3P)→IM1→TS3→IM2→TS8→HOSi+H2. The other minor products include the HSiOH+H, H2SiO+H and HSiO+H2. Furthermore, the products HOSi, HSiO and HSiOH(cis) can undergo dissociation into the product SiO. In addition, the calculations provide a possible interpretation for disagreement about the mechanism of the reaction SiH4+O(3P). It suggests that the products HSiOH, H2SiO and SiO observed by Withnall and Andrews are produced from the secondary reaction SiH3+O(3P) and not from the reaction SiH4+O(3P).     

Eu(OPri)3/Tb(OPri)3共掺杂P(MMA-co-St)

Eu(OPri)3/Tb(OPri)3共掺杂P(MMA-co-St);Eu(OPri)3/Tb(OPri)3;共掺杂;P(MMA-co-St);荧光性能     

Ar(3P0,2)+NH3初生态产物NH2(A2A1)的内态分布

首次报告了在分子束条件下,研究Ar(3P0,2)+NH3碰撞解离反应·利用单光子计数方法进行测量,获得了部分转动分辨的初生态产物NH2(A2A1)→（X2B1）发射谱,并详细地进行了标识·发现主要为[HTSS]（0,v 2',0)→（0,0,0）跃迁（v'≤5,K'a≤6,J'≤10)。通过对部分分辨较好的光谱范围进行了模拟,得到反应生成的NH2(A2A1,v'=2,k'a =1)态绕b/c轴的转动温度为1050K,高于母体分子NH3的转动温度300K。由亚稳态碰撞传能电子交换机理认为这是由于碰撞对手Ar和母体NH3分离时反冲作用的结果。碰撞传能解离机理和光解过程不同,后者仅观察到轴的转动激发。     

~1H(P)、~2H(D)、~3H(T)核磁共振

一般来说,元素氢有三种同位素,即氢~1H或氕P,重氢~2H或氘D以及超重氢~3H或氚T。它们的原子核组成不同,因此核性质亦有所差别(见表1)。     

(1,3,5-C3P3H3)M与(1,3,5-C3P3H3)2M (M=Ti,V, Cr)配合物的结构与芳香性

运用密度泛函理论研究了(1,3,5-C3P3H3)M和(1,3,5-C3P3H3)2M (M=Ti,V,Cr)的结构、键合能以及芳香性.结果表明:低自旋的(1,3,5-C3P3H3)M和(1,3,5-C3P3H3)2M基态结构分别具有C3v和D3h对称性.金属与配体间为共价作用,二者之间存在σ、π和σ三种成键方式.V的三明治配合物的解离方式与Ti和Cr的三明治配合物不同,前者为分步解离,后两者则为一步解离.其中(1,3,5-C3P3H3)2Cr(D3h)的第一解离能最大,配合物最稳定.这些三明治和半三明治配合物都具有中心芳香性、内芳香性和外芳香性,且中心芳香性均大于自由配体(1,3,5-C3P3H3)的中心芳香性,芳香性主要贡献来源于π键和金属原子的孤对电子.内芳香性按照Ti、V、Cr的顺序依次增大,且内芳香性明显要大于外芳香性.高自旋的半三明治(1,3,5-C3P3H3)Ti(C3,5A1)与单重态(1,3,5-C3P3H3)Ti (C3v,1A1)相比,配体的变形性增大,稳定性增加,且C平面中心芳香性和内芳香性均增大,但P平面的中心芳香性却降低.     

CHF_3与O(~3P)反应机理的理论研究

采用从头算MP2/6-311G(d,p)方法研究了CHF3与O(3 P)的反应机理,优化了所有反应物、产物和过渡态的几何构型,并通过振动频率分析和内禀反应坐标(IRC)方法确证了过渡态的真实性.在QCISD(T)/6-311++G(d,p)水平上精确计算了各反应物种的单点能.结果表明,标题反应共存在4类反应,分别为抽提氢反应(R1)、抽提氟反应(R2),消氟化氢反应(R3)和消氢反应(R4),在QCISD(T)/6-311++G(d,p)//MP2/6-311G(d,p)水平上,R1,R2,R3和R4反应的能垒分别为70.7,378.7,294.7和307.2kJ·mol-1,抽提氢反应为主反应通道.     

CIONO2与O(3P)的反应机理

采用密度泛函方法Ｂ３ＬＹＰ／６－３１Ｇ＾＊研究了反应Ｏ（＾３Ｐ）＋ＣｌＯＮＯ２→ＣｌＯ＋ＮＯ３反应Ｏ（＾３Ｐ）＋ＣｌＯＮＯ２→Ｏ２＋ＣｌＯＮＯ的反应机。该结果与大部分实验者的推论是一致的,对于后一反应,其两种反应途径的活化势垒较为相近,表明两种反应途径均是可能的。     

ClONO2与O(3P)的反应机理

采用密度泛函方法Ｂ３ＬＹＰ／６－３１Ｇ研究了反应Ｏ（~（３）Ｐ）＋ＣＩＯＮＯ_２→ＣＩＯ＋ＮＯ_３和反应Ｏ（~（３）Ｐ）＋ ＣＩＯＮＯ_２→Ｏ_２＋ ＣＩＯＮＯ的反应机理．从动力学角度考察,计算结果表明,由于前一反应的活化势垒较低,因而是主要反应．该结果与大部分实验者的推论是一致的,对于后一反应,其两种反应途径的活化势垒较为相近,表明两种反应途径均是可能的．     

31P-NMR and X-ray studies of new rhodium(I) β-ketoiminato complexes Rh(R1C(O)CHC(NH)R2)(CO)(PZ3) where PZ3=PPh3, PCy3, P(OPh)3 or P(NC4H4)3

The substitution of the CO ligand in rhodium(I) β-ketoiminato complexes Rh(R₁{O,N}R₂)(CO)₂ ({O,N}=R₁C(O)CHC(NH)R₂; R₁, R₂=CF₃, Me, CMe₃ in several combinations) by phosphorus ligands PZ₃ (PZ₃=PCy₃, PPh₃, P(OPh)₃, P(NC₄H₄)₃) leads to Rh(R₁{O,N}R₂)(CO)(PZ₃) complexes characterised by ³¹P{¹H}-NMR and X-ray methods. The stronger σ-donor PZ₃ ligands (PZ₃=PCy₃, PPh₃) substitute almost exclusively the CO group trans to N, forming P-trans-to-N isomers. The complexes Rh(CF₃{O,N}Me)(CO)(PCy₃) (II), Rh(CF₃{O,N}CMe₃)(CO)(PCy₃) (III), Rh(CF₃{O,N}Me)(CO)(PPh₃) (IV) and Rh(CF₃{O,N}CMe)(CO)(PPh₃) (V) are of a square-planar geometry with a slight tetrahedral distortion around the rhodium atom in II, III and V. The RhP(PCy₃) bonds are slightly longer than the RhP(PPh₃) bonds. The reaction of stoichiometric amounts of the less basic P(OPh)₃ or P(NC₄H₄)₃ ligands leads to the formation of both isomers of the Rh(R₁{O,N}R₂)(CO)(P(OPh)₃) or Rh(R₁{O,N}R₂)(CO)(P(NC₄H₄)₃) complex in comparable yields. The RhP(P(OPh)₃) distance (2.195(2) Å) in the isomer of Rh(CF₃{O,N}CMe₃)(CO)(P(OPh)₃) with P(OPh)₃ coordinated trans to N (VI) is ca. 0.04 Å longer than in the isomer of that complex with P(OPh)₃ coordinated trans to O (VII). The CO substitution in Rh(R₁{O,N}R₂)(CO)₂ by PZ₃ ligands (PPh₃, PCy₃, P(OPh)₃) causes the shortening of the RhC(CO) bond by ca. 0.04 Å compared to Rh(CF₃{O,N}Me)(CO)₂ (I), making difficult the coordination of another PZ₃ ligand, especially one with stronger σ-donor properties. The more π-acceptor P(OPh)₃ ligands form bis-phosphito complexes and Rh(CF₃{O,N}CMe₃){P(OPh)₃}₂ (VIII) exhibits inequivalence of the two P(OPh)₃ ligands in solution (³¹P-NMR) as well as in solid form (X-ray).     

New ab initio coupled potential energy surfaces for the Br(2P(3∕2), 2P(1∕2)) + H2 reaction

The three lowest (1A('), 2A('), and 1A(')) adiabatic potential energy surfaces (PESs) for the Br((2)P) + H(2) reactive system have been computed based on the multi-reference configuration interaction (MRCI) method including the Davidson's correction with a large basis set. These three adiabatic PESs have been transformed to a diabatic representation, leading to four coupling potentials. In addition, the spin-orbit matrix elements were also obtained using the Breit-Pauli Hamiltonian and the unperturbed MRCI wavefunctions in the Br + H(2) channel and the transition state region. Consequently, six coupling potentials were obtained and their characteristics were extensively discussed. Nonadiabatic quantum dynamics calculations for this system have been realized with these realistic diabatic potentials instead of previous semi-empirical diabatic potentials. Based on two-state model nonadiabatic calculations for the Br((2)P(3∕2), (2)P(1∕2)) + H(2) reaction, the Br((2)P(1∕2)) + H(2) reaction was found to show less reactivity than the Br((2)P(3∕2)) + H(2) reaction at collision energies beyond the threshold of the Br((2)P(3∕2)) + H(2) reaction. Our results are consistent with the previous studies on the XH(2) (X = F, Cl) system, which indicate that the adiabatically forbidden channel is dominant at low energies in the open-shell halogen atom plus H(2) reactions.     

湿化学法合成LiNi_(1/3)Mn_(1/3)Co_(1/3)O_2及其表征(英文)

利用琥珀酸为鳌合剂的湿化学法成功合成了一系列锂离子电池正极材料LiNi1/3Mn1/3Co1/3O2,在合成过程中改变琥珀酸与金属离子摩尔比(R)并研究了这一参数对合成LiNi1/3Mn1/3Co1/3O2材料物理及电化学性质的影响.采用热重、X射线衍射、Rietveld精修、扫描电镜以及超导量子干涉仪对反应机理、材料的结构、形貌以及磁学性质进行了详细表征.得到最佳合成条件为R=1,此时LiNi1/3Mn1/3Co1/3O2的阳离子混排度最低.此外,通过Rietveld精修得到该材料阳离子混排度的结果与通过磁学方法得到的结果定量相符,如对于在R=1条件下合成的样品,Rietveld精修结果显示其阳离子混排度为1.85%,而超导量子干涉仪的测试结果为1.80%.当充放电区间为3.0-4.3V,电流密度为0.2C(1C=160mA·g-1)时,该样品的首次放电容量为161mAh·g-1,库仑效率为93.1%,经过50次循环后,容量保持率可达91.3%.     

LiNi_(1/3)Co_(1/3)Mn_(1/3)O_2的低温性能及动力学分析

通过高温烧结制备了锂离子电池正极材料LiNi1/3Co1/3Mn1/3O2,并用XRD、SEM和恒流充放电对材料的结构、形貌和低温电性能进行了表征,通过线性极化、GITT和EIS等手段研究分析了低温下LiNi1/3Co1/3Mn1/3O2性能变差的原因.结果表明,-20℃时,LiNi1/3Co1/3Mn1/3O2材料的0.1、0.2、1和5 C倍率放电比容量依次为25℃时同倍率下放电比容量的83.2%、68.4%、57.2%和34.1%,放电中值电压比25℃时依次降低了0.049、0.125、0.364和0.531 V.低温充放电过程表现出明显的极化现象,其中最显著的极化来自锂离子穿过活性物质/电解液界面过程以及电荷转移过程,而非锂离子在电极材料内部的扩散过程.