Molecular solid solution of lanthanide-titanium-oxo clusters with enhanced photocatalytic hydrogen evolution

Molecular solid solutions of metal clusters containing different metal centers with well-defined structures can accurately regulate the HOMO-LUMO gap,but are rarely available.Herein,a series of colorless lanthanide-titanium-oxo clusters Ln₂Ti₄(μ₂-O)₂(μ₃-O)₄(Piv)₁₀(THF)₂(Ln₂Ti₄,Ln = Eu,Gd,Tb,and Ce,HPiv = pivalic acid) were synthesized by the reaction of pivalic acid with Ln(Ac)₃     

系列Ln(Ⅲ)配位聚合物(Ln=Eu,Sm,Tb,Pr,Gd)的合成及其荧光分析

采用水热法合成了4个具有1D结构的Ln(Ⅲ)配位聚合物,[Eu₂(C₉H₇O₂)₆(C₉H₇O₂H)(C₂H₅OH)]n(1)、[Sm(C₉H₇O₂)₃]n(2)、[Tb(C₉H₇O₂)₃]n(3)和[Gd(C₉H₇O₂)₃]n(4)(C₉H₈O₂=肉桂酸)。 通过X射线单晶衍射确定了它们的结构。 这4个Ln(Ⅲ)配合物中,Ln(Ⅲ)的配位数均为9,桥配体均为肉桂酸根,但其配位方式有差异。 对配合物进行了IR、UV-Vis-NIR和荧光光谱等表征。 分析了各配合物的荧光发射,结果表明,在可见区,配合物1发射较明显的红光,配合物2、3发射绿光,配合物4发射蓝光,但很弱。 讨论了具有刚柔相混杂性质的肉桂酸配体对配位聚合物的构筑及稀土离子发光的影响。     

稀土氨基酸络合物的研究(Ⅰ)——一氯化三甘氨酸二水合谱的晶体结构

在水溶液中培养了甘氨酸镨、钕的针状晶体,元素分析结果表明可用Ln(Gly)₃Cl₃·3H₂O表示(Ln为Pr,Nd;Gly为甘氨酸)。用X射线衍射方法测定了Pr(Gly)₃Cl₃·3H₂O的单晶结构,其结构式为{[Pr(Gly)₃·(H₂O)₂]·Cl₃·H₂O}_n,属正交晶系,空间群P2₁2₁2₁,每一晶胞中有4个络合单元,形成一维链式聚合物·晶胞参数如下:α=4.779(1)Å,b=12.052(3)Å,c=30.953(11)Å。络合单元中镨为九配位,其配位多面体为畸变的三冠三角棱柱体。     

稀土金属硼氢化物的研究(Ⅰ)——十二氢十二硼酸苯酰肼合稀土金属(Ⅲ)螯合物的合成和性质

本文合成了一系列十二氢十二硼酸苯酰肼合稀土金属(Ⅲ)螯合物,对它们进行了元素分析、红外光谱测定和摩尔电导率的测量,确定化合物的分子式为[Ln(BH)₄]₂(B₁₂H₁₂)₃(BH=苯酰肼),通过DTA法测定了化合物的热稳定性。     

轻稀土硝酸盐及其水合物制备的研究

在文研究了轻稀土硝酸盐及其水合物的几种制备途径,并研究了高水合物的干燥条件。提出了制取Ln(NO₂)₃·nH₂O(Ln=La,Pr,Nd,Sm;n=6,5,4,2,1)和La(NO₃)₃的实验方法。     

四甲基双硅桥联环戊二烯基稀土金属有机配合物的合成及[Me4Si2(C5H4)2Sm(μ-Cl)(THF)]2的晶体结构研究

四甲基双硅桥联环戊二烯基钠与无水三氯化稀土在THF溶剂中反应合成了标题配合物Me₄Si₂(C₅H₄)₂LnCl[Ln:3Nd,4Sm,5Gd,6Y]和配合物Me₄Si₂(C₅H₄):Ln(C₅H₅)(THF)n[Ln:1La,n=1;2Pr,n=0].通过元素分析、¹HNMR、13CNMR和MS确证了配合物的结构,在THF溶液中重结晶获得配合物4的单晶,x射线衍射证明晶体结构为二聚体,4为单斜晶系,空间群为P2₁/c,晶体学数据a=1.2982(3)nm,b=1.2269(3)nm,c=1.3681(2)nm,β=96.79(2)°,V=2.162(1)nm³,Z=2,D_x=1.53g/cm³,偏差因子R=0.068.     

四甲基二硅氧基桥联双环戊二烯基稀土金属配合物的合成及结构研究

在严格的无水无氧条件下无水NdCl₃和SmCl₂与Na₂(C₅H₄SiMe₂)₂O以1:1摩尔比在四氢呋喃溶液中反应,得标题配合物[O(Me₂SiC₅H₄)₂Ln(μ-Cl)(THF)]₂[Ln=Nd(1),Sm(2)].元素分析证明配合物1和2的组成.X射线衍射分析证明1和2是通过氯原子桥联的二聚体结构.     

3-((4，6-二甲基-2-嘧啶基)硫代)-丙酸和菲咯啉三元稀土配合物的晶体结构和发光性能

制备了以3-((4,6-二甲基-2-嘧啶基)硫代)-丙酸(HL)和菲咯啉(Phen)为配体的2个三元稀土配合物[Eu(L)₃(Phen)]₂·2H₂O(1)和[Tb(L)₃(Phen)]₂·2H₂O(2),并对其结构进行了表征。单晶X射线衍射分析表明它们是同构的。2个稀土离子(Ln)由4个羧酸配体桥接,形成二聚体排列。其余2个羧酸配体和Phen以双齿螯合方式与Ln配位。Ln的配位数为9,具有扭曲的单端方形反棱柱配位多面体构型。固态光致发光测试表明,这2种配合物都显示了金属中心的特征发射带。     

基于席夫碱配体构筑的LnⅢ2配合物的结构、荧光性质及生物活性

以多齿席夫碱配体H₂L(H₂L=(E)-N′-(3-乙氧基-2-羟基亚苄基)-3-羟基吡啶甲酰肼)为配体,与Ln(acac)₃·2H₂O(Ln=Tb、Ho、Er;acac^-=乙酰丙酮根)反应,通过溶剂热法,成功得到了3例新的双核稀土配合物[Ln₂(acac)₂(L)₂(C₂H₅OH)₂](Ln=Tb((1)、Ho((2)、Er(3))。单晶X射线衍射分析表明：配合物1～3的结构主要由2个Ln^Ⅲ离子、2个乙酰丙酮根(acac^-)、2个L^2-及2个C₂H₅OH组成,中心Ln^Ⅲ离子通过2个μ₂-O原子相互连接,形成一个平行四边形的Ln₂O₂核心。固体荧光实验测...     

芳基亚胺-脒基稀土烷基化合物的合成及其催化异戊二烯聚合研究

制备了芳基亚胺-脒基稀土二烷基化合物[NNN]Ln(CH₂SiMe₃)₂ {[NNN]=[2-C(H)NDippC₆H₃NHC(Ph)NDipp], Dipp=2,6-i-Pr₂C₆H₃, Ln=Y (2), Sm (3)}, 2和3通过了¹H NMR, ¹³C NMR, IR和元素分析测试, 通过X-ray确定了化合物2的晶体结构. 加入[Ph₃C][B(C₆F₅)₄]和烷基铝, 两个化合物均能高效催化异戊二烯聚合, 具有较好的3,4-选择性(88%), 中等的立体选择性(rr=50%), 较高的分子量(M_n=6.8×10⁴)和较窄的分子量分布(M_w/M_n=1.15). 同时发现, 烷基铝和[Ph₃C][B(C₆F₅)₄]的比例影响催化聚合的区域选择性.     

Studies of a new series of ion-pair complexes [Mo(dtc)_4][Ln(dtc)_4] (Ln=La-Er,exp.Pm)

A new series of ion-pair complexes [Mo(dtc)4][Ln(dtc)4] (Ln=La-Er, exp. Pm) were synthesized from MoCl5, LnCl3 and Nadtc in anhydrous methanol. The crystal structures of the four complexes, [Mo(dtc)4][Ln(dtc)4] (Ln=Nd, Sm, Ho and Er) have been determined by X-ray diffraction. Spectroscopic properties of all these complexes are also discussed here.     

Systematic behavior of charge-transfer transitions and energy level variation in soft donor complexes of the trivalent lanthanides

The systematic behavior of the charge-transfer (CT) energies in mixed 2,2'-bipyridyl (bipy), N,N-diethyldithiocarbamate (Et2dtc-) complexes of the trivalent lanthanides, Ln(Et2dtc)3(bipy), is investigated to understand the electronic structure of f-element complexes containing soft donor ligands. The energies of ligand to Ln3+ CT are extremely low in this system, an effect attributed to the presence of the soft donor ligands. The lowest CT energy level for the Sm3+, Eu3+, and Yb3+ complexes falls into the visible range. In Eu(Et2dtc)(bipy), the Eu3+ ion becomes nonluminescent because the CT energy stretches below the metastable 5D0 electronic state, whereas luminescence from the CT state and the 4f13 (2)F(5/2) state are observed in the Yb compound. The variation in the energy of the lowest level CT transition for the entire Ln(Et2dtc)3(bipy) series has been evaluated using the experimentally determined CT levels of the Sm3+, Eu3+, and Yb3+ compounds based on the systematic behavior of the lanthanides, which is invariant with respect to the type of ligand. The energy difference between the ground electronic states of the lanthanide ions and the ligand-centered valence band may also be calculated from these results.     

Spectroelectrochemical studies of [Mo(dtc)_4][Eu(dtc)_4] and [Mo(dtc)_4][Er(dtc)_4]

Redox and spectroscopic properties of the eight-coordination complexes of molybdenum and the rare-earth elements Eu or Er with N,N-diethyldithiocarbamate (dtc) were characterised by cyclic voltamrnetry and UV-visible absorption spectra.The complex cation [Mo(dtc)4]+ is more stable than the complex anions [Eu(dtc)4]-and [Er(dtc)4]-in redox processes,and possesses good redox reversibility.The electron transfer number,formal standard electrode potential in the redox process for the complex cation and its diffusion coefficients were obtained by in aitu spectroelectro-chemistry.     

Electrochemical and Spectroelectrochemical Studies of Molybdenum and Neodymium Complex with Diethyld

ＥｌｅｃｔｒｏｃｈｅｍｉｃａｌａｎｄＳｐｅｃｔｒｏｅｌｅｃｔｒｏｃｈｅｍｉｃａｌＳｔｕｄｉｅｓｏｆＭｏｌｙｂｄｅｎｕｍａｎｄＮｅｏｄｙｍｉｕｍＣｏｍｐｌｅｘｗｉｔｈＤｉｅｔｈｙｌｄｉｔｈｉｏｃａｒｂａｍａｔｅＬｉｇａｎｄＹＵＺｈｅｎ－ｘｉｎｇ,ＦＵＱ...     

Photochemistry of dithiocarbamate Cu(II) complex in CCl4

Laser pulse photolysis was used to study the nature and reactions of intermediates in the photochemistry of the flat dithiocarbamate complex Cu(Et(2)dtc)(2) in CCl(4). A nanosecond laser pulse (355 nm) is shown to induce intermediate absorption bands of bivalent copper complex whose coordination sphere contains a dithiocarbamate radical Et(2)dtc(?) and a chloride ion at the axial position ([(Et(2)dtc)Cu(Et(2)dtc(?))Cl(a)]). At room temperature during some microseconds after the laser pulse, this intermediate interacts with the initial complex to form presumably a dimer [Cu(2)(Et(2)dtc)(3)(Et(2)dtc(?))Cl]. The latter vanishes in the second-order reaction. Analysis of kinetic and spectral features gives the arguments for the formation of a cluster [Cu(2)(Et(2)dtc)(3)Cl-tds-Cu(2)(Et(2)dtc)(3)Cl], which produces a new absorption band at 345 nm. The cluster decomposes in ～5 ms into final products, a binuclear complex [Cu(2)(Et(2)dtc)(3)Cl] and tetraethylthiuramdisulfide (Et(4)tds).     

Reactions of dithiocarbamates of dimolybdenum—II. Reaction of molybdenum acetate with two equivalents of dithiocarbamate

Reaction of molybdenum acetate with two equivalents of sodium diethyl dithiocarbamate in methanol results in the tetrakis-substituted Mo₂(dtc)₄ (dtc = dithiocarbamate). Exposure of this product to the atmosphere produces Mo₂O₃(dtc)₄.     

Heterotetranuclear Cu_2~IPd_2~Ⅱ Complex with Bis(diphenylphosphino)methane and Diethyldithiocarbamate

1 INTRODUCTION The design of heterometallic complexes of photoluminescnece is of current interest for the inorganic chemists[1, 2]. The coordination flexibility of -dppm ligand as well as the easy substitution of weakly coordinated solvate donors by stronger donors makes the binuclear compound [M2(m- dppm)2(sol)2]2+ excellent building block for con- structing various molecular materials with desired properties[3～5]. We are devoted to developing heterometallic photoluminescent transitio…     

Dimethyldithiocarbamatoarsane und -stibane

Dimethyldithiocarbamatoarsanes and -stibanes The Halogeno-bis(dimethyldithiocarbamato)-compounds (dtc)₂AsCl 1 , (dtc)₂AsBr 2 , (dtc)₂AsI 3 and (dtc)₂SbI 4 are prepared from (dtc)₃As and (dtc)₃Sb resp. Reaction of 1 to 4 with CF₃SO₃Sime₃ yields the ionic compounds (dtc)₂As⁺CF₃SO₃^? 5 and [(dtc)₂El⁺]₂Hal^?(CF₃SO₃^?) · CH₂Cl₂ 6 (El = As; Hal = I), 7 (El = Sb; Hal = I) and 8 (El = As; Hal = Br) resp. by elimination of me₃SiHal. The mass spectra and the main fragmentation from 1 to 8 are reported. The vibrational spectra of these compounds, of As(dtc)₃, Sb(dtc)₃ and of the antimony compounds which are corresponding to 6 and 8 are discussed.     

Charge-transfer photolysis of copper(II) dithiocarbamate mixed-ligand complexes in toluene/alcohol solutions

Charge-transfer (CT)-photolysis of Cu(II) dithiocarbamate mixed-ligand complexes Cu(II)(Et2dtc)X (X = Cl-, Br-) and Cu(II)(Et2dtc)(+)...Y- (Y = ClO4-, NO3-) has been studied in toluene/ROH and compared with our previous data obtained in chloromethane/ROH solutions, where chloromethane = CCl4, CHCl3 or CH2Cl2 and ROH = MeOH, EtOH, i-PrOH or i-BuOH. An EPR evidence is obtained about the formation of a new copper(II) dithiocarbamate mixed-ligand complex during simultaneous photolyses of Cu(II)(Et2dtc)+ and Cu(II)(Et2dtc)2 species in toluene/ROH. The role of the solvent is discussed from the combined analysis of spectrophotometric and EPR data and quantum yield results.     

Thermodynamics of ligand exchange reactions between bis(dithiocarbamato)copper(II) and copper(II) salts. An EPR study

EPR spectroscopy was chosen to investigate the ligand exchange reactions between copper(II) bis(dithiocarbamate), Cu(dtc)2, and copper(II) salts which proceeds with the formation of mixed-ligand complexes of the type Cu(dtc)X, where X = Cl, NO3, ClO4. Large concentrations of 1:1 mixed-ligand complexes of this type are obtained as indicated by the EPR spectra of acetone, CHCl3/EtOH, CHCl3/i-PrOH, CCl4/EtOH and CCl4/i-PrOH, solutions of Cu(dtc)2 and the appropriate copper(II) salt CuCl2, Cu(NO3)2 or Cu(ClO4)2. Double integration of Cu(dtc)2 EPR signals obtained at temperatures between 240 and 310 K affords the calculation of the equilibrium constant (K) of the reaction: Cu(dtc)2 + CuX2 <==> 2 Cu(dtc)X in all solvents as a function of T. From the values of K the stability constant beta of the mixed-ligand complexes has been derived. The error associated with the calculated stability constant is +/- 10%. Thermodynamic parameters (deltaH0, deltaG0 and deltaS0) are determined from the temperature dependence of K as measured by EPR spectroscopy.