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1.
基于DFT-BS方法,采用不同泛函和基组研究了叠氮/吡啶苯甲酸氮氧化物共配叠氮铜配合物[Cu(4,3-opybz)(μ-N3)]n的磁学性质.结果表明,在B3P86/TZVP水平下计算的磁耦合常数(48.20 cm-1)与实验值(49.70 cm-1)最吻合,可准确描述其磁学性质.磁轨道分析表明,Cu(Ⅱ)离子的未成对电子主要集中在3dx2-y2轨道上.顺磁中心与桥联配体间存在强轨道相互作用,其磁轨道主要来源于顺磁中心Cu(1)和Cu(2)的3dx2-y2轨道、吡啶苯甲酸氮氧化物桥联配体羧酸根离子的离域π键和叠氮配体的p轨道.顺磁中心Cu(Ⅱ)主要是自旋离域机理,顺磁中心的自旋离域作用使得与其配位的原子获得了少量的自旋电子.  相似文献   

2.
基于密度泛函理论结合对称性破损态(DFT-BS)方法,运用不同的密度泛函和基组对反铁磁性EO叠氮铜双核配合物[Cu2(dmpe)2(μ1,1-N3)2(CH3COO)]+的磁性质进行研究.结果显示,杂化泛函计算的结果与实验数据非常吻合,能够准确描述反铁磁性EO叠氮铜双核配合物的磁性质.磁轨道分析表明,配合物中存在3个磁通道(2个叠氮桥、1个羧酸桥),磁通道中N原子、O原子与顺磁中心二价铜离子间都存在p d轨道重叠,对体系反铁磁性耦合相互作用都有贡献.从自旋布居分布角度来看,该配合物中顺磁中心间主要是自旋离域作用.配合物中羧酸桥传递强反铁磁性相互作用,使得顺磁中心间磁轨道的重叠增加,体系的反铁磁性相互作用增强.  相似文献   

3.
结合对称性破损(BS)方法, 采用不同的密度泛函理论(DFT)对反铁磁性μ-1,3-N3-Ni(II)叠氮配合物[LNi2(N3)](ClO4)2 (L=pyrazolate)的磁特性进行了研究. 结果显示, 杂化密度泛函理论(HDFT)的计算结果与实验数据非常吻合, 能够准确描述配合物的磁特性. 磁轨道研究结果表明, 配合物表现出较大的单占据轨道能量劈裂(0.93-0.99 eV), 显示配合物的单占据轨道去简并化程度较大, 且配合物中的2 个磁通道(叠氮基、配体pyrazolate)中都分别存在有氮原子之间的p轨道重叠, 这些都使得体系表现为反铁磁耦合作用. 另外, 配合物的磁性与叠氮桥和两金属离子间形成的二面角(τ, Ni-N-N-N-Ni)密切相关, τ从-55.38°逐渐变化到-1.5°的过程中, 其反铁磁性逐渐增强, 交换耦合常数(Jab)的绝对值逐渐增大, 并在-11.95°处达到最大值(Jab=-151.02 cm-1).在此过程中, 配合物中叠氮桥及其所连接的2个Ni 离子与pyrazolate 基配体L-中的2个桥原子N(4)、N(5)形成的七元环共平面性不断增强, 即共平面性会诱导增强体系的反铁磁相互作用.  相似文献   

4.
基于密度泛函理论结合对称性破损态方法,选择不同的泛函方法和基组研究吡唑/草酸根混合配位的非对称双核铜配合物的磁学性质。结果表明,在B3LYP/def2-TZVP水平计算的磁耦合常数为-127.24cm~(-1),与实验值-129cm~(-1)基本吻合,可准确描述吡唑/草酸根混合配位的非对称双核铜配合物的磁学性质。磁轨道和自旋布居分析表明,顺磁中心Cu(Ⅱ)与桥联配体草酸根离子间存在较强的轨道相互作用,其磁轨道主要由顺磁中心Cu(Ⅱ)的3d_x2_(-y)2轨道、桥联配体草酸根离子的π键组成,顺磁中心Cu(Ⅱ)主要是自旋离域机理。配合物磁性与结构关系的研究表明,随着结构参数τ的增加,顺磁中心HS态和BS态自旋密度的平方差和自然磁轨道间重叠积分的平方随之增大,反铁磁性相互作用的贡献增大,配合物磁耦合常数J值减小。  相似文献   

5.
罗树常 《分子科学学报》2020,(1):62-68,I0005
基于DFT-BS方法,选择不同的泛函方法和基组,研究anti,anti甲酸桥联双核铜配合物的磁学性质.结果表明,在B3P86/TZV水平计算得到顺磁中心Cu(Ⅱ)离子间磁耦合常数为-55.63 cm^-1,与实验值-55.60 cm^-1最接近,可准确描述甲酸桥联双核铜配合物的磁学性质.顺磁中心Cu(Ⅱ)与甲酸根桥联配体间有较强的轨道作用,其磁轨道主要来源于Cu(Ⅱ)离子的3dyz轨道、桥联配体甲酸根离子的离域π键,顺磁中心Cu(Ⅱ)离子为自旋离域机理.在不同桥联模式的甲酸桥联双核铜配合物中,随顺磁中心Cu(1)自旋密度增加,Cu(Ⅱ)离子间的反铁磁性贡献逐渐增加,其磁耦合常数J值逐渐减小.  相似文献   

6.
基于DFT-BS方法,在不同泛函和基组下研究酚氧/苯甲酸共配Fe~ⅢNi~Ⅱ双核配合物[Fe~Ⅲ(OBz)(L_1)Ni~Ⅱ(H_2O)(μ-OBz)]~+的磁学性质.结果表明,在B3LYP*/def2-TZVP水平下计算的磁耦合常数为0.45 cm~(-1),与实验值0.50 cm~(-1)最吻合,可准确描述其磁学性质.自旋布居分析和分子磁轨道分析显示,顺磁中心Fe~Ⅲ和Ni~Ⅱ主要为自旋离域机理.顺磁中心Fe~Ⅲ,Ni~Ⅱ与桥联配体间存在强的轨道相互作用,其磁轨道贡献主要来自顺磁中心Fe~Ⅲ的3d_(x~2-y~2)轨道/3d_(z~2)轨道/3d_(yz)轨道、Ni~Ⅱ的3d_(x~2-y~2)轨道/3d_(z~2)轨道、苯甲酸的π轨道和酚氧桥联配体O原子的p轨道.磁构关系研究表明,随Fe—O—Ni键角θ的增大,顺磁中心Fe~Ⅲ和Ni~Ⅱ自旋密度减小,其顺磁中心间的磁耦合常数减小,当Fe—O—Ni键角θ95.69°时,顺磁中心间的磁相互作用由铁磁性相互作用向反铁磁性相互作用转变.  相似文献   

7.
3-氨基-1-羟基丙叉-1,1-二膦酸与钴或铜离子的水热反应得到新的配聚物Co2(NH3CH2CH2C(OH)(PO3)(PO3H))2·2H2O (1) 和Cu3{[NH3CH2CH2C(OH)(PO3)2](H2O)2} (2).研究了两个配合物的热稳定性,采用变温磁化率研究了在5-300 K范围内的磁性能. 结果表明:在配合物1中,钴离子间存在着弱的反铁磁偶合作用,理论拟合值为J=-2.1 cm-1,g=2.18;配合物2中,铜离子间的磁作用较复杂.  相似文献   

8.
三种新型铜配合物的合成、结构及理论计算   总被引:1,自引:0,他引:1  
合成了一个柔性配体1,3-二(N-咪唑基甲基)苯(mbix)(1), 并将其与不同Cu盐组装, 得到3个新配合物[Cu(mbix)2(H2O)]·2NO3·CH3OH(2), [Cu(mbix)(N3)(OAc)]·CH3OH(3)和[Cu(mbix)2]·SiF6·2CH3OH(4), 并对其进行了元素分析、红外光谱及X 射线单晶结构分析表征. 配合物2拥有二维二重贯穿结构, 配合物3中两个铜离子通过两个叠氮酸根桥连成双核铜, 它再通过配体连接形成一维绞链状结构, 而配合物4通过配体桥联成一维无限链状结构. 结果显示, 平衡阴离子在配合物的组装过程中起着非常重要的作用. 此外还对配体及3个配合物中配体的构象进行了理论计算.  相似文献   

9.
孙友敏  刘成卜  王若曦 《化学学报》2004,62(23):2303-2307
用密度泛函理论结合对称性破损态方法对氮氧双自由基以及铜(Ⅱ)-氮氧自由基配合物的磁耦合常数进行了计算.结果表明铜(Ⅱ)-氮氧自由基配合物为铁磁耦合.对配合物磁轨道进行了分析,表明体系的铁磁耦合作用主要来自于Cu离子的轨道与自由基的π*轨道正交.自旋密度分布分析显示:在氮氧自由基与金属铜两个自旋耦合片的自旋耦合主要来自于中心Cu离子的轨道电子向氮氧自由基上的π*轨道的电子转移,这一电子特征的变化引起的自旋离域在Cu离子和氮氧自由基片的铁磁耦合中起到了重要的作用.  相似文献   

10.
采用普通溶液法合成了单核铈配合物[Ce(4-aba)3(4-abaH)(phen)2]·H2O(4-abaH=对氨基苯甲酸,phen=1,10-邻菲罗啉)。X射线单晶衍射结果表明:该配合物晶体属单斜晶系,P21/c空间群,晶胞参数:a=1.8896(4)nm,b=1.9755(4)nm,c=1.3200(3)nm,β=97.235(2)°,V=4.8880(18)nm3,Mr=1064.06,Dc=1.446 g·cm-3,Z=4,μ=0.996 mm-1。中心铈离子的配位环境为变形的三帽三棱柱体。配合物存在着π-π堆积及丰富的氢键,将配合物扩展为三维超分子结构。  相似文献   

11.
The spectral-polarization characteristics of absorption and phosphorescence of molecules of the initial form of nitro-substituted indolinospirobenzothiopyran were studied in oriented polyethylene films and in solutions with different polarity. An oscillator model of the electron transitions responsible for the formation of absorption and luminescence spectra was suggested. It was established that the principal differences in the spectral and photophysical properties of the compound studied and its oxygen-containing analog are associated with the fact that the electronegativity of the S atom is lower than that of the O atom. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1143–1146, June, 1997.  相似文献   

12.
非那雄胺能抑制5α-还原酶的活性,明显降低二氢睾酮水平,是一种治疗良性前列腺增生的有效药品。该合成工艺以甾烯酮酸为原料,将其与氯化亚砜反应,无须分离即与叔丁胺反应得17β-酰胺化合物,再氧化开环,环合,氢化,脱氢合成了非那雄胺。经元素分析、IR、1HNMR、13CNMR、MS分析表征了其结构。该法无须使用昂贵的2,2-二吡啶二硫化物和剧毒药品苯亚硒酸酐,且以乙酸铵代替氨气,降低了对设备的要求和腐蚀,更适用于工业生产。  相似文献   

13.

The heats of detonation of 20 simple high explosives and explosive mixtures were determined by means of an adiabatic detonation calorimeter designed by the authors. The results indicated that the performance of the instrument was reliable and the experimental data were very accurate. For explosive mixtures, there was a linear accumulative relationship between the heats of detonation of the explosive mixture and its components. Accordingly, the heats of detonation of explosive mixtures could be calculated directly from the heats of detonation of simple explosives and the characteristic heats of other components. The experiments showed that the gold or brass shell of the cylindrical charge could be substituted by a thick-walled porcelain shell, which had the advantage of cheapness.

  相似文献   

14.
Two vanilloids, (5E)-8-(4-hydroxy-3-methoxyphenyl)oct-5-en-4-one (1) and 4-[3-hydroxydecyl]-2-methoxyphenol (2), isolated from the dried seeds of Grains of Paradise (Aframomum melegueta), were synthesized; the latter compound was made as the S-enantiomer and the material derived from the seeds was found to be a 1:1.7 mixture of the R and S isomers. The synthetic route used should allow the preparation of analogs having extended alkyl chains and consequently different lipophilicity, and 3, a homolog of 2, was also prepared.  相似文献   

15.
In this review, the research of the author in the field of colloidal systems is summarized. The factors influencing colloidal stability are systematized and analyzed. Examples are presented to illustrate the practical utilization of the theory of stability of colloids and thin films.This review was prepared on the basis of the works of the author, which were awarded the State Premium for 1991 in the field of science and technology, chemistry section.Institute of Physical Chemistry, Russian Academy of Sciences, 117915 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 8, pp. 1708–1717, August, 1992.  相似文献   

16.
Main hydration products of two cement pastes, i.e. CSH-gel, portlandite (P) (and specific surface S) were studied by static heating, and by SEM, TEM and XRD, as a function of cement strength (C-33 and C-43) hydration time (th) and subsequent hydration in water vapour.Total change in mass on hydration and air drying, Mo, increased with strength of cement paste and with hydration time. Content of water escaping at 110 to 220°C, defined as water bound with low energy, mainly interlayer and hydrate water, was independent on cement strength but its content increased with (th). Content of chemically bound (zeolitic) water in CSH-gel, escaping at 220-400°C, was slightly dependent on strength and increased with (th). It was possibly derived from the dehydroxylation of CSH-gel and AFm phase. Portlandite water, escaping at 400-500°C, was independent on cement strength and was higher on longer hydration. Large P crystals were formed in the weaker cement paste C-33. Smaller crystals were formed in C-43 but they increased with (th). Carbonate formated on contact with air (calcite, vaterite and aragonite), decomposed in cement at 600-700oC. It was high in pastes C-33(1 month) and C-43(1 month), i.e. 5.7 and 3.3%, respectively; it was less than 1% after 6 hydration months (low sensitivity to carbonation) in agreement with the XRD study showing carbonates in the air dry paste (1month), and its absence on prolonged hydration (6 months) and on acetone treatment. Water vapour treatment of (6 months) pastes or wetting-drying increased this sensitivity.Nanosized P-crystals, detected by TEM, could contribute to the cement strength; carbonate was observed on the rims of gel clusters.This revised version was published online in November 2005 with corrections to the Cover Date.  相似文献   

17.
翟宗玺  刘树深  夏树屏 《化学学报》1990,48(10):946-950
用氧化镁氯化镁水溶液制备了8水合氯氧化镁[nMg(OH)2·MgCl2·8H2O], 并测定了其在盐酸中的溶解热, 实验结果表明, 氯氧化镁溶解热与n值呈线性关系, 根据溶解热求出5Mg(OH)2·MgCl2·8H2O和3Mg(OH)2·MgCl2·8H2O的生成热分别为-7727.1和5888.1kJ·mol^1^-。  相似文献   

18.
The enthalpies of solution of several oxosulfides of rare-earth elements and the high-temperature enthalpies of oxosulfides and oxosulfates of lanthanum and yttrium were measured using solution calorimetry and high-temperature microcalorimetry techniques. Standard enthalpies of formation and some thermodynamic properties of oxosulfides and oxosulfates were calculated. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2 pp. 294–297, February, 1997.  相似文献   

19.
20.
针对恶臭测试的环境影响问题,提出了解决的实例方案,并对方案的要点及优缺点进行讨论,此方案在实际操作中具有较好的效果。  相似文献   

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