含羧基的三核钼原子簇

本文总结了作者研究的一组合有羧基的三核钼原子簇的结果。这些簇合物分为两类。第一类有: (C_2H_5)_4N[Mo_3(μ_3-O)(μ-O_2CH)_3(μ-Cl)_3Cl_3] (Ⅰ) (CH_3)_4N[Mo_3(μ_3-O)(μ-O_2CH)_3(μ-Cl)_3Cl_3] (Ⅱ) (CH_3)_4N[Mo_3(μ_3-O)(μ-O_2CH)_3(μ-Br)_3Cl_3] (Ⅲ) (C_5H_7S_2)[Mo_3(μ_3-O)(μ-O_2CCH_3)_3(μ-Cl)_3Cl_3] (Ⅳ) (C_5H_7S_2)[Mo_3(μ_3-O)(μ-O_2CCH_3)_3(μ-Br)_3Cl_3] (Ⅴ) (C_2H_5)_4N[Mo_3(μ_3-O)(μ-O_3CCH_3)(μ-Cl)_3X_3] (Ⅵ) (X为Cl和Br统计分布的簇合物) (C_2H_5)_4N[Mo_3(μ_3-O)(μ-O_2CCH_2CH_3)_3(μ-Cl)_3Cl_3] (Ⅶ) (C_2H_5)_4N[Mo_3(μ-O)(μ-O_2CCH_2CH_2CH_3)_3(μ-Cl)_3Cl_3] (Ⅷ) (Ⅰ)-(Ⅷ)的簇阴离子具有下述通式: [Mo_3(μ_3-O)(μ-O_2CR)_3(μ-X)_3X_3~′]~-; R=H,CH_3,CH_3CH_3,CH_2CH_2CH_2:X和X′=Cl或Br。 属于第二类型的目前只有一个,即: [(C_2H_5)_4N]_2[Mo_3(μ_3-O)(μ-O_2CCH_3)_2(μ-Cl)_3Cl_5) (Ⅸ) 本文将扼要介绍这些簇合物的合成方法,晶体和分子结构的主要特征,并对成簇规律、结构变化规律以及μ_3-O的红外光谱的指认,给予简单的讨论。     

双帽羧桥三核钨(Ⅳ)原子簇化合物的结构研究

用新的合成途径,以Na_2WO_4·2H_2O为原料,Zn粉为还原剂,合成了三个簇合物(1)[W_3O_2(CH_3CO_2)_6(H_2O)_3]ZnBr_4·8H_2O,(2)H(W_3O_2(CH_3CO_2)_9]·5H_2O,(3)H_2Na_3[W_3O(CCH)_3(CH_3CO_2)_6(H_2)O][H_2W_(12)O_(40)]·13.5H_2O。在测定晶体结构和综合有关文献基础上,说明了反应过程,并进行了EHMO量化计算,探讨了该类型化合物的簇骼成键性质和相关的物理,化学性质。     

IR和ESR法考察PtNaY,PdNaY和CoNaY沸石催化剂

研究了Pt(NH_3)_4NaY,Pd(NH_3)_4NaY及Co(NH_3)_6NaY沸石在不同热处理条件下红外谱图变化的规律。发现该沸石晶穴中这些络离子在250℃下抽空1小时,其结构均破坏;若再在400～500℃区间加热1小时,其表面均有Si—H键生成,并讨论了Si—H键生成的机理。用D_2交换法证明了这些络离子破坏后,在PtNaY,PdNaY及CoNaY沸石表面分别有Pt-H,Pd—H及Co—H键存在,它们是由于NH_3在这些沸石表面高温分解所放出的H吸附在这些金属离子上的结果。由IR与ESR法证明室温下于NaY沸石晶穴中可合成出[Co(NH_3)_5O_2]~(2+)与[Co(NH_2CH_2CH_2NH_2)_2O_2]~(2+)离子;在适当的条件下,于Y型沸石表面可合成出一种特殊的Co络合物载氧体,ESR证明它易将2,6-二特丁基对甲酚氧化成自由基。     

希土硼氢化物的研究 Ⅹ.含[B_(10)H_9NH_2COCH=CH_2]~-的双苯甲酰丙酮缩1,3—丙二胺希土(Ⅲ)配合物的研究

将闭式+氢+硼酸阴离子酰胺衍生物[B_(10)H_9NH_2COCH=CH_2]~-、双苯甲酰丙酮缩1,3-丙二胺C_6H_5C(OH)=CHC(CH_3)=N(CH_3)CH=C(OH)C_6H_5(Bapn)及希土氯化物在丙酮-乙醇混合溶剂中进行反应,得到分子式为Ln(Bapn)_3[B_(10)H_9NH_2COCH=CH_2]_3(Ln=La,Nd,Sm,Eu,Gd,Dy)的混式配体希土配合物。通过元素分析、IR、~1H NMR及摩尔电导率的测定对配合物进行了表征,还通过DTA-TG方法研究了它们的热性质。     

固相配位化学反应研究ⅩⅩⅩⅩⅢ.[Co(NH_3)_4CO_3]Cl、[Co(en)_2CO_3]Cl与NH_4SCN的固相取代反应

本文研究了[Co(NH_3)_4CO_3]Cl、[Co(en)_2CO_3]C1分别与NH_4SCN在100℃发生的固相取代反应.[Co(NH_3)_4CO_3]Cl与NH_4SCN反应生成trans-[Co(NH_3)_4(NCS)_2]~+;[Co(en)_2CO_3]Cl与NH_4SCN反应先生成cis-[Co(en)_2(NCS)_2]~+,然后转化成trans-(Co(en)_2(NCS)_2]~+。采用气相色谱、红外光谱、X粉末衍射和核磁共振法对相应反应体系及其产物进行了测试,推测反应按S_(N~2)机理进行。     

[(CH_3)_4N]_2[Mo_2S_8O_2]的合成与晶体结构

S~(2-)作为配位方式多变的配位基,已为人们所知,而以S_4~(2-)为配位基的钼化合物,现在还为数不多。我们合成的[Mo_2S_8O_2]~(2-)不仅含有S_2~(2-)、S_4~(2-)基,还含有端基氧,其结构是很有趣的。混合(NH_4)_6Mo_7O_(24)·4H_2O和NH_2OH·HCl的水溶液,与K_2S反应后,用(CH_3)_4NBr沉淀,产物再用丙酮和DMF混合液重结晶,得[(CH_3)_4N]_2[Mo_2S_8O_2]的极薄的橙色片状晶体。其元素组成是:Mo 30.7,S40.5,C15.6,N4.3,H4.0(％);计算值为:Mo30.4,S40.8,C15.3,N4.6,H3.9(％)。     

基于CH_3NH_3Pbl_3单晶的Ta_2O_5顶栅双极性场效应晶体管（英文）

具有无机-有机杂化钙钛矿结构的CH_3NH_3Pbl_3通常偏向于显示n型半导体特性,本文以五氧化二钽(Ta_2O_5)作为绝缘层,制备了基于钙钛矿CH_3NH_3Pbl_3单晶的顶栅结构场效应晶体管,暗态下更明显地观察到了CH_3NH_3Pbl_3所具有的p型场效应特性,空穴场效应迁移率达到8.7×10~(-5)cm~2·V~(-1)·s~(-1),此暗态空穴迁移率比原有报道的基于CH_3NH_3Pbl_3多晶薄膜的SiO_2底栅场效应晶体管提高了一个数量级。此外,光照对CH_3NH_3Pbl_3单晶场效应晶体管的性能有强烈影响。与底栅结构CH_3NH_3Pbl_3多晶场效应晶体管不同,即使有栅极和绝缘层的遮挡,5.00 mW·cm~(-2)的光照仍可使CH_3NH_3Pbl_3单晶场效应晶体管的空穴电流提高一个数量级(V_(GS)(栅源电压)=V_(DS)(漏源电压)=20 V),光响应度达到2.5 A·W~(-1)。本文工作实现了对CH_3NH_3Pbl_3场效应晶体管载流子传输的选择性调控,表明在没有外部因素的参与下,通过合适的器件设计,CH_3NH_3Pbl_3同样具有制备成双极性晶体管的潜力。     

C_6H_2(OH)_3CH_3氧化成羟基苯甲酸反应路径的DFT研究

运用密度泛函(DFT)理论,采用Materials Studio 8.0,用GGA/BP方法研究了C_6H_2(OH)_3CH_3氧化成羟基苯甲酸的反应路径。结果表明,甲基上的氢原子被氧化成羟基以及羟基被氧化为醛基及醛基被氧化成羧基均为放热过程。分子C_6H_2(OH)_3CH_3中甲基氧化成羧基的主路径为三个氢原子氧化反应路径,其路径为C_6H_2(OH)_3CH_3+3O→C6H2(OH)3C(OH)3→C6H2(OH)3COOH+H2O,该路径受限于羟基直接被氧化成羧基过程,需克服130 k J/mol的反应势垒,反应速率常数对数ln(k)为-22.96 s-1;醛基、羟基优先被氧化成羧基的顺序为:-CHO-C(OH)3-HC(OH)2-H2C(OH);提高反应温度、氧气浓度均有利于羟基苯甲酸的生成,适当的催化剂有利于促进整个反应的进行。     

酸性介质中1,2-丙二醇在铂电极上吸附和氧化过程的原位FTIR反射光谱研究

应用电化学循环伏安和原位FTIR反射光谱研究1,2-丙二醇在Pt电极上吸附和氧化过程。结果指出1,2-丙二醇的电氧化可按双途径进行。其一经1,2-丙二醇在Pt上解离吸附产物氧化至CO_2。但在较低电位下这些解离吸附产物(红外检测为CO_(ad)、[﹥C=CH_2]_(ad)等)累积吸附于电极上, 毒化Pt表面抑制其它反应。当电位大于0.3 V后它们一经生成即氧化脱附, 从而使1,2-丙二醇得以在未毒化Pt表面经反应中间体氧化至CO_2。在实验条件下,原位FTIR反射光谱检测到的反应中间体可能有HOC-CHOHCH_3(或CH_2OHCOCH_3)和HOOC-COCH_3(或HOOC-CHOHCH_3)等物种。     

酸性介质中1,2-丙二醇在铂电极上吸附和氧化过程的原位FTIR反射光谱研究

应用电化学循环伏安和原位FTIR反射光谱研究1,2-丙二醇在Pt电极上吸附和氧化过程。结果指出1,2-丙二醇的电氧化可按双途径进行。其一经1,2-丙二醇在Pt上解离吸附产物氧化至CO_2。但在较低电位下这些解离吸附产物(红外检测为CO_(ad)、?C=CH_2]_(ad)等)累积吸附于电极上,毒化Pt表面抑制其它反应。当电位大于0.3V后它们一经生成即氧化脱附,从而使1,2-丙二醇得以在未毒化Pt表面经反应中间体氧化至CO_2。在实验条件下,原位FTIR反射光谱检测到的反应中间体可能有HOC-CHOHCH_3(或CH_2OHCOCH_3)和HOOC-COCH_3(或HOOC-CHOHCH_3)等物种。     

稀土冠醚配合物的XPS研究

近几年来,XPS已应用于研究稀土元素及其配合物的内层电子结合能,伴峰现象以及镧系化合物性质变化规律。我们合成了1,2-环己基-12-冠-4(C_(12)H_(22)O_4)与稀土离子(RE=La—Er,Y)的二元配合物,苯并-15-冠-5(B-15-C-5)、联吡啶与稀土离子(RE=La—Eu)的混合配体配合物。本文报导用XPS研究上述两类配合物的中心金属离子的3d_(5/2)的结合能变化规律以及伴峰现象;研究配合物以及配位体的N_(1S)和O_(1S)结合能,并通过比较结合能的变化规律,讨论了配位键的性质。     

用XPS对La1-xSrxCoO3的研究——Ⅲ. LaCoO3的还原及表面状态

本文用XPS研究了LaCoO_3在不同温度下氢气还原的情况, 并表征了钴的还原度。用X-光衍射了解还原后LaCoO_3为金属钴和La_2O_3二相。通过La 3d_(5/2)峰与其shake-up伴峰之间的距离确定La是以La(OH)_3的形式存在于表面。     

卤化亚铜三苯基膦络合物的XPS振起伴峰及其价带谱研究

卤化亚铜三苯基膦络合物(Ph_3P)_3Cu_nX_n(n=1,2;X=Cl,Br,I和CN)具有较好的催化活性和选择性,因而引起了人们的注意。X射线衍射研究表明(Ph_3P)_3CuX中Cu具有四配位的结构,而(Ph_3P)_3Cu_2X_2中Cu却具有四配位和三配位的结构。由XPS来表征它们的成键特征的工作尚未见诸报道。实验按文献[6]所述方法制备络合物。经熔点测定、元素分析,证实所制样品的纯度符合要求。按标准方法纯化氯化亚铜和溴化亚铜,并将新制样品置于充满高纯氮的干燥器中。测试     

Disulfide bond cleavage induced by a platinum(II) methionine complex

The cleavage of a disulfide bond and the redox equilibrium of thiol/disulfide are strongly related to the levels of glutathione (GSH)/oxidized glutathione (GSSG) or mixed disulfides in vivo. In this work, the cleavage of a disulfide bond in GSSG induced by a platinum(II) complex [Pt(Met)Cl2] (where Met = methionine) was studied and the cleavage fragments or their platinated adducts were identified by means of electrospray mass spectrometry, high-performance liquid chromatography, and ultraviolet techniques. The second-order rate constant for the reaction between [Pt(Met)Cl2] and GSSG was determined to be 0.4 M(-1) s(-1) at 310 K and pH 7.4, which is 100- and 12-fold faster than those of cisplatin and its monoaqua species, respectively. Different complexes were formed in the reaction of [Pt(Met)Cl2] with GSSG, mainly mono- and dinuclear platinum complexes with the cleavage fragments of GSSG. This study demonstrated that [Pt(Met)Cl2] can promote the cleavage of disulfide bonds. The mechanistic insight obtained from this study may provide a deeper understanding on the potential involvement of platinum complexes in the intracellular GSH/GSSG systems.     

Structures of copper(II) complexes with dihydrobenzoxazine derivatives in chloroform

Copper(II) complexes CuL₂ (HL = 2-(2-hydroxyphenyl)-4,4-diphenyl-1,2-dihydro-4H-3,1-benzoxazine and 2-(2-hydroxy-5-nitrophenyl)-4,4-diphenyl-1,2-dihydro-4H-3,1-benzoxazine) in chloroform were studied by EPR and electronic absorption spectroscopy. It was found that the complexation involves the azomethine forms of the ligands, which are coordinated by the Cu atom through the phenol and azomethine fragments of both ligands. The electronic absorption spectra were decomposed into Gaussian components to determine the d-d transition energies. The parameters of the complexation were calculated in terms of the angular overlap model. The order of energy arrangement of the orbitals of the central atom was determined: $d_{x^2 - y^2 } \gg d_{xy} > d_{z^2 } > d_{xz} > d_{yz} $ .     

Hydroxamic acid dinuclear complexes of molybdenum(V) and molybdenum(III)

Summary Molybdenum(V) and molybdenum(III) complexes [Mo₂O₃L₄] and [Mo₂L₆] derived from hydroxamic acids (HL) were prepared and identified by Raman, i.r., e.s.r., electronic spectra and analytical data. The low magnetic moments of the dinuclear complexes are due to in part to intramolecular interactions. Electronic spectra and vibrational studies indicate the presence of a Mo₂O₃ core in the molybdenum(V) complexes. The relative intensities of the, main and satellite peaks in e.s.r. spectra indicate the dinulcear nature of molybdenum(III) hydroxamates.     

Bi2Sr2CuO6的电子结构和铜氧对间电荷涨落

自发现含铋铜氧化物的高温超导性以来,采用各种复杂程度方法对电子结构的计算已经在文献中报道.它们集中讨论了能带结构,态密度和Fermi面的性质,但很少报道铜氧对间的电荷涨落。而价态变动对超导电性起着至关重要的作用,因此本文对Bi_2Sr_2CuO_6进行了紧束缚带计算,探讨了电子缺陷和氧呼吸式振动对铜和氧电荷分布的影响。     

协萃络合物结构的研究——二(1-苯基 -3-甲基-4-三氟乙酰基吡唑啉酮-5)-(1，10菲啰啉)合钴(II)的合成、表征与晶体结构的测定

合成了二(1-苯基-3-甲基-4-三氟乙酰基吡唑啉酮-5)-(1,10菲啰啉)合钴(Ⅱ)混合配体络合物单晶, 由元素分析确定其组成为Co(C_(12)H_3F_3O_2N_2)_2·(C_(12)H_8N_2)。通过溶解性、摩尔电导, 磁性、中红外光谱、远红外光谱、差热、热重分析研究了该化合物的有关性质。用四园单晶衍射仪, 测定了该络合物的分子及晶体结构。晶体属单斜晶系, P2_(l/o)空间群,晶胞参数为:a=1.0422(3) nm, b=1.6462(2) nm, c=2.0678(3) nm, β=75.86(1)°, V=3.4402(1.6) nm, Z=4, F(000)=1580, d_(calc)=1.50 g cm~(-3), d_(exp.)=1.492g cm~(-3)。经最小二乘法修正后, 最终偏差因子R=0.0716。配合物中钴的配位数为六, 分子中有四个氧来自两个双齿配体PMTFP, 两个氮原子由phen所提供。     

Zn(II) complexes of glutathione disulfide: structural basis of elevated stabilities

Glutathione disulfide (GSSG), a long disregarded redox partner of glutathione (GSH), is thought to participate in intracellular zinc homeostasis. We performed a concerted potentiometric and NMR spectroscopic study of protonation and Zn(II) binding properties of GSSG ((γECG)(2)) and a series of its nine analogs with C-terminal modifications, tripeptide disulfides: (γECS)(2), (γECE)(2), (γECG-NH(2))(2), (γECG-OEt)(2), and (γEcG)(2); dipeptide disulfides, (γEC)(2) and (γEC-OEt)(2); and mixed disulfides, γECG-γEC and γECG-γEC-OEt. The acid-base and Zn(II) complexation properties in this group of compounds are strictly correlated to average C-terminal electrostatic charges. In particular, it was demonstrated that GSSG assumes a bent (head-to-tail) conformation in solution at neutral pH, which is controlled by electrostatic attraction between the protonated γ-amino groups of the Glu residue and the deprotonated C-terminal Gly carboxylates. This interaction modulates the ability of GSSG to coordinate Zn(II), both indirectly, by affecting the basicities of the amino groups, and directly, through the participation of the Gly carboxylates in the outer coordination sphere of the Zn(II) ion. A specific coiled structure of the major [Zn-GSSG](2-) complex is additionally stabilized by the formation of hydrogen bonds between glycinyl carboxylates and two Zn(II)-coordinated water molecules. The elevated stability of Zn(II)-GSSG complexes was demonstrated by competition with FluoZin-3, a fluorescent sensor with high Zn(II) affinity, commonly used in in vitro and in vivo studies. The potential biological functions and reactivity of GSSG complexes of Zn(II) ions are discussed.     

MX2(AsH3)2(M=Pd,Pt;X=Cl,Br,I)的含时密度泛函理论研究

采用密度泛函方法(B3LYP)优化了MX2(AsH3)2[M=Pd；X=Cl(1)，Br(2)，I(3)和M=Pt；X=Cl(4)，Br(5)，I(6)]的基态结构，得到的几何参数与实验结果符合．以基态几何为基础，将TD-DFT方法用于计算标题配合物的电子吸收光谱．研究结果表明，金属的dx2-y2与配体所组成的反键轨道为LUMO轨道，从而该类配合物具有d-d跃迁属性的吸收带；在多数跃迁过程中，配体也有较大的贡献．