稀土铽超分子纳米功能材料的荧光性质比较

稀土配合物Tb(Phen)x(Bipy)(4-x)(NO3)3(x=4,3,2,1,0)(1×10-3mol·L)溶液中,当配体邻菲罗琳(Phen)和2,2′ 联吡啶(Bipy)共存同一铽的配合物中时,Tb3+的特征发光被敏化,其中Tb(Phen)3(Bipy)(NO3)3的荧光强度是最强,Tb(Bipy)4(NO3)3的荧光强度是最弱。Tb3+在(CH3)3Si MCM 41 Tb(Bipy)4(NO3)3中的特征发光强度最强,而在MCM 41 Tb(Phen)3(Bipy)(NO3)3和(CH3)3Si MCM 41 Tb(Phen)3(Bipy)(NO3)3中的发光变得很弱。当客体分子Tb(Phen)4(NO3)3和Tb(Bipy)4(NO3)3被组装到疏水的主体分子筛(CH3)3Si MCM 41孔道里要比组装到亲水的分子筛MCM 41孔道里的发光要强;当客体分子是Tb(Phen)3(Bipy)(NO3)3和Tb(Phen)2(Bipy)2(NO3)3时,它们的发光情况与前一种情况刚好相反即亲水的极性内腔环境有利于客体分子的发光;平行的荧光寿命试验的结论也是一致的。说明在不同的超分子体系中,疏水和亲水的环境都有可能利于客体分子的发光。在(CH3)3Si MCM 41 Tb(Phen)(Bipy)3(NO3)3中的配体的荧光强度要比在MCM 41 Tb(Phen)(Bipy)3(NO3)3中的强;而Tb3+的特征荧光强度的情况刚好相反。MCM 41 Tb(Phen)(Bipy)3(NO3)3和(CH3)3Si MCM 41 Tb(Phen)(Bipy)3(NO3)3有明显的双指数衰减,双指数衰减拟合所得荧光寿命分别为168.8,641.1μs和73.2,5     

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。     

基于CaBa_2(BO_3)_2中的Ce~(3+)→Tb~(3+)能量传递及光谱特性

采用高温固相法合成了Ce3+,Tb3+掺杂激活的CaBa2(BO3)2荧光粉,并对其发光特性进行了研究。观察到CaBa2(BO3)2中Ce3+对Tb3+发光的敏化现象。在367 nm紫外光激发下,单掺Tb3+时CaBa2(BO3)2不发光。当Ce3+和Tb3+共掺时,出现Tb3+的发射峰,样品发绿光,表明Ce3+对Tb3+的发光有很强的敏化作用。根据Forster-Dexter理论,分析Ce3+和Tb3+的能量传递过程,还证明在CaBa2(BO3)2:Ce3+,Tb3+中Ce3+对Tb3+的能量传递属于共振能量传递。     

(Y,Gd)Al3(BO3)4∶Ce,Tb的光谱特性及稀土离子间的能量传递

采用高温固相反应合成了(Y,Gd)Al3(BO3)4中掺杂Ce3 和Tb3 的样品,并研究了其结构特性、光谱特性和发光过程中稀土离子间的能量传递.(Y,Gd)Al3(BO3)4属于三角晶系,具有R32的空间群,掺入Ce3 ,Tb3 杂质后晶格结构没有变化.(Y,Gd)Al3(BO3)4∶Ce,Tb的激发光谱由3个宽谱带组成,这3个谱带分别对应于Ce3 的4f-5d跃迁吸收.在该体系中存在Ce3 →Tb3 ,Gd 3 →Tb3 和Gd3 →Ce3 的能量传递,其中Ce3 起敏化剂和中间体的双重作用.     

Relative reactivities of halogen-substituted substrates (R-Br,R-C1) toward the halophilic attack by a carbanion

Relative reactivities of bromine-substituted substrates (R-Br) or chlorine-substituted substrates (R-CI) toward bromophilic or chlorophilic attack by a carbanion have been evaluated by the intermolecular competition kinetics. Relative reactivity orders are CF3CFBr2 >CF3CBr3≥CBr4 > CHBr3 > CF3CFBrCF2Br > CF2Br2 > BrCF2CF2Br > BrCH2CO2Et≥ BrCF2CFHBr > CH2Br2 > BrCH2CH2Br, and CI3CNO2 > CI3CCN > CI3CCOPh > cyclo-C5CI6> CI3CCOCI > CCI3CF2CI > CCI3CF3 ≥ CCI4 > CCI3CCI3 ≥ CCI3(CF2)2CI > CI3CCOCCI3 > CCI3(CF2)6CI > CI3CCO2Et > CI3CF > CI3CPh>CI3CCH2O2CCH3.     

二甲基甲酰胺中钐盐的电导研究

通过电导测量研究了4种钐盐:Sm(CF3SO3)3,Sm(ClO4)3,Sm(NO3)3,和SmCl3在极性非质子溶剂DMF中的电导性质。利用线性拟合方法求得在25℃下Sm(CF3SO3)3和Sm(ClO4)3的极限摩尔电导率分别为274 5和283 2S·cm2·mol-1。用间接方法求得Sm(NO3)3与SmCl3的极限摩尔电导率分别为299 7,289 8S·cm2·mol-1。在25～65℃温度范围内,Sm(CF3SO3)3和Sm(ClO4)3的电导率随温度呈线性变化。Sm(NO3)3,SmCl3的电导行为表现出明显的离子缔合。     

（Y，Gd）Al3（BO3）4：Ce，Tb的光谱特性及稀土离子间的能量传递

采用高温固相反应合成了(Y，Gd)Al3(BO3)4中掺杂Ce^3 和Tb^3 的样品，并研究了其结构特性、光谱特性和发光过程中稀土离子问的能量传递。(Y，Gd)Al3(BO3)4属于三角晶系，具有R32的空间群，掺入Ce^3 ，Tb^3 杂质后晶格结构没有变化。(Y，Gd)Al3(BO3)4：Ce，Tb的激发光谱由3个宽谱带组成，这3个谱带分别对应于Ce^3 的4f-5d跃迁吸收。在该体系中存在Ce^3 →Tb^3 ，Gd^3→Tb^3 和Gd^3 →Ce^3 的能量传递，其中Ce^3 起敏化剂和中间体的双重作用。     

多氟烯烃和炔烃的钯催化氢化

本文报道Pd/Al_2O_3(1%)催化剂催化氢化CF_3CCl=CClCF_3,CF_3CCI==CHCF_3和CF_3C=CCF_3等多氟烯烃和炔烃的结果。经1~H和(19)~F核磁共振、质谱、红外等分析,证明了用制备色谱分离后的氢化产物主要成份的结构。前二者的氢化产物中主要是CF_3CH_2CH_2CF_3和CF_3CH_2CHClCF_3的混合物,而CF_3C=CCF_3氢化后只生成CF_3CH_2CH_2CF_3。     

YF3:Eu3+纳米纤维/高分子复合纳米纤维的制备与表征

采用静电纺丝技术制备了Y2O3:Eu3+纳米纤维,使用NH4HF2为氟化剂,经双坩埚法氟化和脱氨后得到YF3:Eu3+纳米纤维,再采用静电纺丝技术制备了YF3:Eu3+纳米纤维/PVP复合纳米纤维. XRD分析表明,立方相的Y2O3:Eu3+氟化后,得到了正交相的YF3:Eu3+纳米纤维,空间群为Pnma;YF3:Eu3+纳米纤维/PVP复合纳米纤维具有明显的YF3:Eu3+的衍射峰. SEM分析表明,YF3:Eu3+纳米纤维与YF3:Eu3+纳米纤维/PVP复合纳米纤维的直径分别为91±11 nm、319±43 nm,表面光滑. 用Shapiro-Wilk方法检验,纤维直径属于正态分布. 荧光光谱分析表明,YF3:Eu3+纳米纤维和YF3:Eu3+纳米纤维/PVP复合纳米纤维的最强发射峰均位于588 nm和595 nm,属于Eu3+的5D0→7F1跃迁,表明Eu3+占据YF3基质中Y3+晶格点的C2对称格位. PVP对YF3:Eu3+发光峰位没有影响,但发光强度降低;YF3:Eu3+的含量与YF3:Eu3+纳米纤维/PVP复合纳米纤维的发光强度成线性关系.     

LiNO_3-KNO_3-H_2O三元体系相平衡研究

本文采用等温法分别测定了KNO3-H2O体系的溶解度相图以及LiNO3-KNO3-H2O体系在273.15和298.15K的等温溶解度相图。结果表明在273.15K时LiNO3-KNO3-H2O体系的溶解度等温线有2条分支,对应的固相分别为KNO3和LiNO3·3H2O,共饱点组成为31.55wt%LiNO3和7.07wt%KNO3。该体系在298.15K的等温线有3条分支,对应的固相分别为KNO3,LiNO3和LiNO3·3H2O,2个共饱点组成分别为50.42wt%LiNO3,22.18wt%KNO3,和55.74wt%LiNO3,10.9wt%KNO3。     

Hydrogen and halogen bonding in the haloetherification products in chalcone

Cooperative action of hydrogen and halogen bonding in the reaction of 3‐(3,5‐di‐tert‐butyl‐4‐hydroxyphenyl)‐1‐phenylprop‐2‐en‐1‐one with HCl or HBr in alcohol medium under microwave irradiation (20 W, 80 °C, 10 min) allows the isolation of the haloetherification products (2S,3S)‐3‐(3‐tert‐butyl‐5‐chloro‐4‐hydroxyphenyl)‐2‐chloro‐3‐ethoxy‐1‐phenylpropan‐1‐one, C₂₁H₂₄Cl₂O₃, (2S,3S)‐2‐bromo‐3‐(3‐tert‐butyl‐5‐bromo‐4‐hydroxyphenyl)‐3‐methoxy‐1‐phenylpropan‐1‐one, C₂₀H₂₂Br₂O₃, and (2S,3S)‐2‐bromo‐3‐(3‐tert‐butyl‐5‐bromo‐4‐hydroxyphenyl)‐3‐ethoxy‐1‐phenylpropan‐1‐one, C₂₁H₂₄Br₂O₃, in good yields. Both types of noncovalent interactions, e.g. hydrogen and halogen bonds, are formed to stabilize the obtained products in the solid state.     

An Extremely Bulky Tris(pyrazolyl)methanide: A Tridentate Ligand for the Synthesis of Heteroleptic Magnesium(II) and Ytterbium(II) Alkyl,Hydride, and Iodide Complexes

The tris(pyrazolyl)methane compound HC(3‐Ad‐5‐Mepz)₃ [ 1 , 3‐Ad‐5‐Mepz=3‐(1‐adamantyl)‐5‐methylpyrazolyl] and its regioisomer, HC(3‐Ad‐5‐Mepz)₂(3‐Me‐5‐Adpz), were synthesized and crystallographically characterized. Deprotonation of 1 with MeLi afforded the lithium complex [{κ³‐N‐C(3‐Ad‐5‐Mepz)₃}Li(thf)], which incorporates a tris(pyrazolyl)methanide ligand of unprecedented bulk. Reaction of 1 with MeMgI gave the ionic coordination complex [{κ³‐N‐HC(3‐Ad‐5‐Mepz)₃}MgMe]I, which was readily deprotonated to afford the neutral compound [{κ³‐N‐C(3‐Ad‐5‐Mepz)₃}MgMe]. The related magnesium butyl compound [{κ³‐N‐C(3‐Ad‐5‐Mepz)₃}MgBu] was prepared from the reaction of 1 and MgBu₂. Treating this with LiAlH₄ or LiAlD₄ led to rare examples of terminal magnesium hydride/deuteride complexes, [{κ³‐N‐C(3‐Ad‐5‐Mepz)₃}MgH/D]. All neutral magnesium alkyl and hydride compounds were crystallographically authenticated. Reaction of [{κ³κN‐C(3‐Ad‐5‐Mepz)₃}Li(thf)] with [YbI₂(thf)₂] yielded the first structurally characterized f‐block tris(pyrazolyl)methanide complex, [{κ³‐N‐C(3‐Ad‐5‐Mepz)₃}YbI(thf)].     

The structures of 1,4‐diaryl‐5‐trifluoromethyl‐1H‐1,2,3‐triazoles related to J147, a drug for treating Alzheimer's disease

J147 [N‐(2,4‐dimethylphenyl)‐2,2,2‐trifluoro‐N′‐(3‐methoxybenzylidene)acetohydrazide] has recently been reported as a promising new drug for the treatment of Alzheimer's disease. The X‐ray structures of seven new 1,4‐diaryl‐5‐trifluoromethyl‐1H‐1,2,3‐triazoles, namely 1‐(3,4‐dimethylphenyl)‐4‐phenyl‐5‐trifluoromethyl‐1H‐1,2,3‐triazole (C₁₇H₁₄F₃N₃, 1 ), 1‐(3,4‐dimethylphenyl)‐4‐(3‐methoxyphenyl)‐5‐trifluoromethyl‐1H‐1,2,3‐triazole (C₁₈H₁₆F₃N₃O, 2 ), 1‐(3,4‐dimethylphenyl)‐4‐(4‐methoxyphenyl)‐5‐trifluoromethyl‐1H‐1,2,3‐triazole (C₁₈H₁₆F₃N₃O, 3 ), 1‐(2,4‐dimethylphenyl)‐4‐(4‐methoxyphenyl)‐5‐trifluoromethyl‐1H‐1,2,3‐triazole (C₁₈H₁₆F₃N₃O, 4 ), 1‐[2,4‐bis(trifluoromethyl)phenyl]‐4‐(3‐methoxyphenyl)‐5‐trifluoromethyl‐1H‐1,2,3‐triazole (C₁₈H₁₀F₉N₃O, 5 ), 1‐(3,4‐dimethoxyphenyl)‐4‐(3,4‐dimethoxyphenyl)‐5‐trifluoromethyl‐1H‐1,2,3‐triazole (C₁₉H₁₈F₃N₃O₄, 6 ) and 3‐[4‐(3,4‐dimethoxyphenyl)‐5‐(trifluoromethyl)‐1H‐1,2,3‐triazol‐1‐yl]phenol (C₁₇H₁₄F₃N₃O₃, 7 ), have been determined and compared to that of J147 . B3LYP/6‐311++G(d,p) calculations have been performed to determine the potential surface and molecular electrostatic potential (MEP) of J147 , and to examine the correlation between hydrazone J147 and the 1,2,3‐triazoles, both bearing a CF₃ substituent. Using MEPs, it was found that the minimum‐energy conformation of 4 , which is nearly identical to its X‐ray structure, is closely related to one of the J147 seven minima.     

Transition‐Metal Complexes Based on the 1,3,5‐Triethynyl Benzene Linking Unit

The synthesis of a unique series of heteromultinuclear transition metal compounds is reported. Complexes 1‐I‐3‐Br‐5‐(FcC≡C)‐C₆H₃ ( 4 ), 1‐Br‐3‐(bpy‐C≡C)‐5‐(FcC≡C)‐C₆H₃ ( 6 ), 1,3‐(bpy‐C≡C)₂‐5‐(FcC≡C)‐C₆H₃ ( 7 ), 1‐(XC≡C)‐3‐(bpy‐C≡C)‐5‐(FcC≡C)‐C₆H₃ ( 8 , X = SiMe₃; 9 , X = H), 1‐(HC≡C)‐3‐[(CO)₃ClRe(bpy‐C≡C)]‐5‐(FcC≡C)‐C₆H₃ ( 11 ), 1‐[(Ph₃P)AuC≡C]‐3‐[(CO)₃ClRe(bpy‐C≡C)]‐5‐(FcC≡C)‐C₆H₃ ( 13 ), 1‐[(Ph₃P)AuC≡C]‐3‐(bpy‐C≡C)‐5‐(FcC≡C)‐C₆H₃ ( 14 ), [1‐[(Ph₃PAuC≡C]‐3‐[{[Ti](C≡CSiMe₃)₂}Cu(bpy‐C≡C)]‐5‐(FcC≡C)‐C₆H₃]PF₆ ( 16 ), and [1,3‐[(tBu₂bpy)₂Ru(bpy‐C≡C)]₂‐5‐(FcC≡C)‐C₆H₃](PF₆)₄ ( 18 ) (Fc = (η⁵‐C₅H₄)(η⁵‐C₅H₅)Fe, bpy = 2,2′‐bipyridiyl‐5‐yl, [Ti] = (η⁵‐C₅H₄SiMe₃)₂Ti) were prepared by using consecutive synthesis methodologies including metathesis, desilylation, dehydrohalogenation, and carbon–carbon cross‐coupling reactions. In these complexes the corresponding metal atoms are connected by carbon‐rich bridging units comprising 1,3‐diethynyl‐, 1,3,5‐triethynylbenzene and bipyridyl units. They were characterized by elemental analysis, IR and NMR spectroscopy, and partly by ESI‐TOF mass spectrometry., The structures of 4 and 11 in the solid state are reported. Both molecules are characterized by the central benzene core bridging the individual transition metal complex fragments. The corresponding acetylide entities are, as typical, found in a linear arrangement with representative M–C, C–C_C≡C and C≡C bond lengths.     

A structural study of 4‐aminoantipyrine and six of its Schiff base derivatives

Six derivatives of 4‐amino‐1,5‐dimethyl‐2‐phenyl‐2,3‐dihydro‐1H‐pyrazol‐3‐one (4‐aminoantipyrine), C₁₁H₁₃N₃O, (I), have been synthesized and structurally characterized to investigate the changes in the observed hydrogen‐bonding motifs compared to the original 4‐aminoantipyrine. The derivatives were synthesized from the reactions of 4‐aminoantipyrine with various aldehyde‐, ketone‐ and ester‐containing molecules, producing (Z)‐methyl 3‐[(1,5‐dimethyl‐3‐oxo‐2‐phenyl‐2,3‐dihydro‐1H‐pyrazol‐4‐yl)amino]but‐2‐enoate, C₁₆H₁₉N₃O₃, (II), (Z)‐ethyl 3‐[(1,5‐dimethyl‐3‐oxo‐2‐phenyl‐2,3‐dihydro‐1H‐pyrazol‐4‐yl)amino]but‐2‐enoate, C₁₇H₂₁N₃O₃, (III), ethyl 2‐[(1,5‐dimethyl‐3‐oxo‐2‐phenyl‐2,3‐dihydro‐1H‐pyrazol‐4‐yl)amino]cyclohex‐1‐enecarboxylate, C₂₀H₂₅N₃O₃, (IV), (Z)‐ethyl 3‐[(1,5‐dimethyl‐3‐oxo‐2‐phenyl‐2,3‐dihydro‐1H‐pyrazol‐4‐yl)amino]‐3‐phenylacrylate, C₂₂H₂₃N₃O₃, (V), 2‐cyano‐N‐(1,5‐dimethyl‐3‐oxo‐2‐phenyl‐2,3‐dihydro‐1H‐pyrazol‐4‐yl)acetamide, C₁₄H₁₄N₄O₂, (VI), and (E)‐methyl 4‐{[(1,5‐dimethyl‐3‐oxo‐2‐phenyl‐2,3‐dihydro‐1H‐pyrazol‐4‐yl)amino]methyl}benzoate, C₂₀H₁₉N₃O₃, (VII). The asymmetric units of all these compounds have one molecule on a general position. The hydrogen bonding in (I) forms chains of molecules via intermolecular N—H...O hydrogen bonds around a crystallographic sixfold screw axis. In contrast, the formation of enamines for all derived compounds except (VII) favours the formation of a six‐membered intramolecular N—H...O hydrogen‐bonded ring in (II)–(V) and an intermolecular N—H...O hydrogen bond in (VI), whereas there is an intramolecular C—H...O hydrogen bond in the structure of imine (VII). All the reported compounds, except for (II), feature π–π interactions, while C—H...π interactions are observed in (II), C—H...O interactions are observed in (I), (III), (V) and (VI), and a C—O...π interaction is observed in (II).     

Proton‐Assisted Hydrogen Activation on Polyhedral Cations

The treatment of [1,1‐(PR₃)₂‐3‐(Py)‐closo‐1,2‐RhSB₉H₈] (PR₃=PMe₃ ( 2 ) or PPh₃ and PMe₃ ( 3 ); Py=pyridine) with triflic acid (TfOH) affords [1,3‐μ‐(H)‐1,1‐(PR₃)₂‐3‐(Py)‐1,2‐RhSB₉H₈]⁺ (PR₃=PMe₃ ( 4 ) or PMe₃ and PPh₃ ( 5 )). These products result from the protonation of the 11‐vertex closo‐cages along the Rh(1)? B(3) edge. These unusual cationic rhodathiaboranes are stable in solution and in the solid state and they have been fully characterized by multinuclear NMR spectroscopy. In addition, compound 5 was characterized by single‐crystal X‐ray diffraction. One remarkable feature in these structures is the presence of three {Rh(PPh₃)(PMe₃)}‐to‐{ηⁿ‐SB₉H₈(Py)} (n=4 or 5) conformers in the unit cell, thus giving an uncommon case of conformational isomerism. [1,1‐(PPh₃)₂‐3‐(Py)‐closo‐1,2‐RhSB₉H₈] ( 1 ), that is, the bis‐PPh₃‐ligated analogue of compounds 2 and 3 , is also protonated by TfOH, but, in marked contrast, the resulting cation, [1,3‐μ‐(H)‐1,1‐(PPh₃)₂‐3‐(Py)‐1,2‐RhSB₉H₈]⁺ ( 6 ), is attacked by a triflate anion with the release of a PPh₃ ligand and the formation of [8,8‐(OTf)(PPh₃)‐9‐(Py)‐nido‐8,7‐RhSB₉H₉] ( 9 ). The result is an equilibrium that involves cationic species 6 , neutral OTf‐ligated compound 9 , and [HPPh₃]⁺, which is formed upon protonation of the released PPh₃ ligand. The resulting ionic system reacts readily with H₂ to give cationic species [8,8,8‐(H)(PPh₃)₂‐9‐(Py)‐nido‐8,7‐RhSB₉H₉]⁺ ( 7 ). This reactivity is markedly higher than that previously found for compound 1 and it introduces a new example of proton‐assisted H₂ activation that occurs on a polyhedral boron‐containing compound.     

6‐Chloroisocytosine and 5‐bromo‐6‐methylisocytosine: again,one or two tautomers present in the same crystal?

It is well known that pyrimidin‐4‐one derivatives are able to adopt either the 1H‐ or the 3H‐tautomeric form in (co)crystals, depending on the coformer. As part of ongoing research to investigate the preferred hydrogen‐bonding patterns of active pharmaceutical ingredients and their model systems, 2‐amino‐6‐chloropyrimidin‐4‐one and 2‐amino‐5‐bromo‐6‐methylpyrimidin‐4‐one have been cocrystallized with several coformers and with each other. Since Cl and Br atoms both have versatile possibilities to interact with the coformers, such as via hydrogen or halogen bonds, their behaviour within the crystal packing was also of interest. The experiments yielded five crystal structures, namely 2‐aminopyridin‐1‐ium 2‐amino‐6‐chloro‐4‐oxo‐4H‐pyrimidin‐3‐ide–2‐amino‐6‐chloropyrimidin‐4(3H)‐one (1/3), C₅H₇N₂⁺·C₄H₃ClN₃O⁻·3C₄H₄ClN₃O, (Ia), 2‐aminopyridin‐1‐ium 2‐amino‐6‐chloro‐4‐oxo‐4H‐pyrimidin‐3‐ide–2‐amino‐6‐chloropyrimidin‐4(3H)‐one–2‐aminopyridine (2/10/1), 2C₅H₇N₂⁺·2C₄H₃ClN₃O⁻·10C₄H₄ClN₃O·C₅H₆N₂, (Ib), the solvent‐free cocrystal 2‐amino‐5‐bromo‐6‐methylpyrimidin‐4(3H)‐one–2‐amino‐5‐bromo‐6‐methylpyrimidin‐4(1H)‐one (1/1), C₅H₆BrN₃O·C₅H₆BrN₃O, (II), the solvate 2‐amino‐5‐bromo‐6‐methylpyrimidin‐4(3H)‐one–2‐amino‐5‐bromo‐6‐methylpyrimidin‐4(1H)‐one–N‐methylpyrrolidin‐2‐one (1/1/1), C₅H₆BrN₃O·C₅H₆BrN₃O·C₅H₉NO, (III), and the partial cocrystal 2‐amino‐5‐bromo‐6‐methylpyrimidin‐4(3H)‐one–2‐amino‐5‐bromo‐6‐methylpyrimidin‐4(1H)‐one–2‐amino‐6‐chloropyrimidin‐4(3H)‐one (0.635/1/0.365), C₅H₆BrN₃O·C₅H₆BrN₃O·C₄H₄ClN₃O, (IV). All five structures show R₂²(8) hydrogen‐bond‐based patterns, either by synthon 2 or by synthon 3, which are related to the Watson–Crick base pairs.     

Novel dinuclear and trinuclear ruthenium clusters derived from 2‐aryl‐substituted indenylphosphines via C─H bond cleavage

Treatment of Ru₃(CO)₁₂ with an equivalent of (2‐phenyl‐1H ‐inden‐3‐yl)dicyclohexylphosphine ( 1 ) and (2‐pyridyl‐1H ‐inden‐1‐yl)dicyclohexylphosphine ( 4 ) in refluxing heptane gave the novel trinuclear ruthenium clusters (μ₃‐η¹:η²:η⁵–2‐phenyl‐3‐Cy₂PC₉H₄)Ru₃(CO)₈ ( 1c ) and [μ₂‐η¹–2‐(pyridin‐2‐yl)‐3‐Cy₂PC₉H₆]Ru₃(CO)₉ ( 4a ), respectively, via C ─ H bond cleavage. (2‐Mesityl‐1H ‐inden‐3‐yl)dicyclohexylphosphine ( 2 ) reacted with Ru₃(CO)₁₂ in refluxing heptane to give the trinuclear ruthenium cluster [μ‐2‐mesityl‐(3‐Cy₂PC₉H₅)](μ₂‐CO)Ru₃(CO)₉ ( 2c ) via C ─ H bond cleavage and carbonyl insertion. 2‐(Anthracen‐9‐yl)‐1H –inden‐3‐yldicyclohexylphosphine ( 3 ) reacted with Ru₃(CO)₁₂ in refluxing heptane to give the dinuclear ruthenium cluster [μ₂‐η³:η³–2‐(anthracen‐9‐yl)‐3‐Cy₂PC₉H₆]Ru₂(CO)₅ ( 3a ). The structures of 1c , 2c , 3a and 4a were fully characterized using IR and NMR spectroscopy, elemental analysis and single‐crystal X‐ray diffraction. These results suggest that the 2‐aryl substituent on the indenyl ring has a pronounced effect on the reaction and coordination modes of Ru₃(CO)₁₂.     

New CuII and CdII Metal‐organic Coordination Polymers with 1,2,4‐triazolo[3,4‐b]‐1,3,4‐thiadiazole Ligands: Syntheses,Structures and Luminescent Properties

Three new complexes {[Cu( L¹ )₂(NO₃)₂]?H₂O}_oo ( 1 ), {[Cu₄( L² )₂(OAc)₈]‐CH₃CH₂OH}_oo ( 2 ) and [Cd₂( L³ )₃(NO₃)₄(H₂O)₂]_oo ( 3 ) ( L¹= 4‐phenyl‐7‐(pyridine‐3‐yl)‐1,2,4‐triazolo[3,4‐b]‐1,3,4‐thiadiazole, L²= 4‐(pyridine‐3‐yl)‐7‐phenyl‐1,2,4‐triazolo[3,4‐b]‐1,3,4‐thiadiazole, and L³= 4‐(pyridine‐4‐yl)‐7‐phenyl‐1,2,4‐triazolo[3,4‐b]‐1,3,4‐thiadiazole) have been synthesized and characterized by elemental analyses, IR spectra and single crystal X‐ray diffraction. The structural analyses reveal that complex 1 is a neutral 2‐D network structure with a 4⁴ topology, 2 has a 1‐D neutral coordination chain with a [Cu₂(CH₃COO)₄] dinuclear structural unit bridged by four acetate ions, and 3 is a neutral rhombohedral grid structure. All the complexes are air stable at room temperature. Furthermore, the fluorescent properties of complex 3 and corresponding ligand L³ have been investigated and discussed.     

Synthesis,characterization, electrochromic properties,and electrochromic device application of a novel star polymer consisting of thiophene end‐capped poly(ε‐caprolactone) arms emanating from a hexafunctional cyclotriphosphazene core

Hexa‐armed and thiophene (Thi) end‐capped poly(ε‐caprolactone) star polymer (N₃P₃‐(PCL‐Thi)₆), containing cyclotriphosphazene core, was prepared in a four‐step reaction sequence. Ring‐opening polymerization (ROP) and “click chemistry” techniques were employed in the first and final steps, respectively. Hexa‐armed PCL star polymer (N₃P₃‐(PCL‐OH)₆) was successfully synthesized via ROP of ε‐caprolactone (ε‐CL) by using hekzakis(p‐(hydroxymethyl)phenoxy) cyclotriphosphazene as the multisite initiator and tin(II) 2‐ethylhexanoate (Sn(Oct₂)) as the catalyst in bulk at 115 °C. Further modifications of the N₃P₃‐(PCL‐OH)₆ were accomplished by derivatization of the hydroxyl‐functional chain ends. The obtained N₃P₃‐(PCL‐OH)₆ was then reacted with 2‐bromo‐2‐methylpropanoyl bromide, and this led to a star polymer with bromide end groups, N₃P₃‐(PCL‐Br)₆. In the third step, N₃P₃‐(PCL‐Br)₆ was azidified with sodium azide (NaN₃) in DMF affording N₃P₃‐(PCL‐N₃)₆. Conversion of the azide chain end groups into Thi was quantitatively accomplished via the “click reaction” between N₃P₃‐(PCL‐N₃)₆ and prop‐2‐yn‐1‐yl 3‐thienyl acetate in the final step. Subsequently, the star polymer with six Thi chain ends (N₃P₃‐(PCL‐Thi)₆) was employed in electrochemical copolymerization with both pyrrole and Thi. Electrochromic properties and electrochromic device application of N₃P₃‐(PCL‐Thi)₆/PThi were also investigated. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 3668–3682, 2010