TMB·TCNQ和硬脂酸混合LB膜的制备及表征

将没有双亲性的电荷转移配合物TMB·TCNQ (TMB：3, 3′,5,5′-Tetramethylbenzidine;TCNQ：7,7,8,8-tetracyanoquinodimethane)通过与硬脂酸混合组装制备了混合LB膜。TMB·TCNQ和硬脂酸的摩尔比例在1∶1, 1∶2和1∶3的情况下都可以成功进行组装。利用紫外-可见-近红外光谱、透射和掠角反射红外光谱、X射线衍射以及原子力显微镜研究了混合LB膜中各组分的结构、分子取向和表面形貌等。研究结果表明,混合LB膜中的TMB·TCNQ是混合堆积排列的,电荷转移度ρ约为0.35。配合物中的电子给体TMB和电子受体TCNQ分子的苯环平面都垂直于基底表面。硬脂酸的碳氢长链以一定角度倾斜于基底表面。混合LB膜的小角X射线衍射图中出现了两组衍射峰。混合比例为1∶1的单层和多层LB膜中出现纳米棒和微粒,而且,纳米棒和粒子的数量随着LB膜层数的增加而增多。     

基于TCNQ电荷转移化合物的合成与光谱性质

π电子受体TCNQ的电荷转移化合物有奇特的电学和磁学性质,在该类电荷转移化合物中,TCNQ的形态对化合物的性质有较大的影响。文章合成了两种电荷转移化合物[RBz(4-CH₃)Py][TCNQ](R=Br(1),I(2)),通过元素分析、红外光谱和拉曼光谱对其进行了表征。这两种化合物的元素分析结果显示与理论值一致。通常在2 200 cm-1附近的C≡N的伸缩频率经常被用来确定TCNQ分子的电荷,TCNQ中性分子的ν(CN)在2 222 cm-1以上,而这两种化合物的ν(CN)都向低波数移动,在2 185～2 156 cm-1之间。通过对两种化合物红外和拉曼光谱的测定,显示了其中的TCNQ形态是TCNQ阴离子自由基（TCNQ－）。     

新型多氮杂环金属配合物的合成及其光谱研究

采用溶液析出法,合成了以2-(2′-羟基-5′-甲基苯基)苯并三唑(HMPB)为配体的多氮杂环金属配合物M(HMPB)₂(M=Co, Ni),利用元素分析、激光解析飞行时间质谱等进行了表征,并研究了新配合物的红外特征光谱和紫外-可见电子吸收光谱。结果表明：HMPB配体通过N和O原子与中心金属以二齿形式配位,中心金属的配位数为4;配合物红外特征吸收谱带位于400～2 500 cm-1,形成金属配合物后,2-(2′-羟基-5′-甲基苯基)苯并三唑的羟基的伸缩振动吸收、CN振动峰和C─O特征吸收有明显改变,同时确定了配位键M─N和M─O的特征峰位置;配合物在紫外区有强吸收,其最大吸收峰位于335～345 nm。     

新型酞菁的光致发光性质研究

研究了2,3-四-(2-异丙基一5-甲基苯氧基)氢酞菁在10,77,177和300 K下石英衬底上的浇铸膜和单晶硅衬底上真空镀膜(约200 nm厚)在300 K下光致发光光谱.氢酞菁的浇铸膜光致发光光谱在上述温度下均出现荧光发射和磷光发射峰,在177和300 K下出现了1 673 nm激基缔合物峰.该峰的出现与分子抗聚集能力的强弱有关,在300 K激基缔合物峰比在177 K下的峰强,从氢酞菁分子结构特点讨论了形成激基缔合物的原因.随着温度的升高,可以观察到荧光发射峰渐渐减弱而激基缔合物峰变强.由于浇铸膜和真空镀膜的酞菁分子聚集态不同导致了斯托克司位移的差异,真空镀膜的发光峰峰值在1 140 nm左右,与酞菁浇铸膜的峰值差别较大.浇铸膜的发光峰的半高宽为300 nm,而真空镀膜发光峰的半高宽为100 nm左右.     

2,9-二正丁基-1,10-菲咯啉双核铜(Ⅰ)配合物的合成、晶体结构及光学性质

以2,9-二正丁基-1,10-菲咯啉(dnbp)和碘化亚铜为原料,在四氢呋喃溶液中反应合成了一种新型中性双核铜(Ⅰ)配合物[CuI(dnbp)]2。采用X射线单晶衍射、核磁共振氢谱、紫外-可见吸收光谱表征其结构,荧光光谱测定其发光性能。结果表明:该配合物分子由两个Cu(Ⅰ)离子通过两个碘离子桥联形成畸变的菱形Cu2I2核心和dnbp螯合配体构成,配合物中I—Cu—I的夹角较小(106.08°),两个Cu(Ⅰ)离子的距离很长(0.319 4 nm),表明它们的相互作用可以忽略。上述结构的特征主要由dnbp配体大的空间位阻造成。配合物晶体属于三方晶系,空间群为R-3,晶胞参数a=4.404 14(11)nm,b=4.404 14(11)nm,c=1.085 92(4)nm,γ=120°,V=18.241 1(9)nm3。配合物在二氯甲烷溶液中出现350～500 nm的吸收峰,归属于金属离子到配体的电荷转移跃迁(MLCT)。室温下,当激发波长为365 nm时,其最大发射波长为653 nm,发光寿命为3.1μs,光致发光量子产率为0.013。发光机制属于金属离子和卤素到配体电荷转移激发态的磷光发射。低温下,配合物最大发射波长蓝移至645 nm,发射峰变窄。     

Bei四羧酸铈在TiO2纳米晶膜上的光电转化性质

报道了Ce^3 和Ce^4 两种金属离子桥联Bei四羧酸在二氧化钛纳米晶电极上自组装膜的制备,并利用紫外可见光谱、红外光谱、光电子能谱等手段对自组装膜进行了表征．通过同步辐射光电子能谱确定了自组装膜的HOMO能级．基于自组装膜缺化二氧化钛纳米晶电极的薄层三明治型太阳能电池具有较好的光电传化性质．在480nm,Bei四羧酸敏化二氯化钛电极产生了26．9％的入射单色光子-电子转化效率(IPCE),而由Ce^4 离子或Ce^3 离子桥联所形成的自组装膜分别产生了55．8％和39.1％的IPCE．金属离子桥联Bei四羧酸自组装膜相当于一种配合物,其HOM0能级比Bei四羧酸自组装膜的高,这是形成铈离子桥联Bei四羧酸后IPCE提高的一个主要原因,     

2-烷基TCNQ的红外光谱和结构研究——CH_2剪式振动的双峰与晶体场分裂的关系(英文)

测量了2-烷基TCNQ(C8TCNQ,C12TCNQ,C18TCNQ)浇铸膜的红外光谱,发现这类化合物的红外CH2剪式振动在1 471和1 462 cm-1处显示2个峰。这2个峰的强度比(I1 471/I1 462)随着烷基链的长度增加而明显减少。另外,来自CH2的1 471 cm-1吸收峰与来自TCNQ环的1 529 cm-1吸收峰的相对强度随着碳链的长度增加而不发生变化。CnTCNQ系列化合物的红外光谱CH2的剪式振动行为与长链脂肪酸中CH2行为很不相同。在长链脂肪酸中,晶体场效应导致了剪式振动分裂。考虑C12TCNQ的晶体结构,而将1 471cm-1峰归属为非叉指对接的碳链,将1 462 cm-1峰归于叉指对接的碳链,双峰的出现与晶体场分裂无关。并且得到烷基TCNQ中,非叉指对接的碳链的长度与碳链总长度无关的结论。     

稀土Tb3+,Eu3+对N-苯基邻氨基苯甲酸及邻菲咯啉间能量传递与蓝色发射的强化作用

合成了一种由稀土离子与N—苯基邻氨基苯甲酸(N—HPA)和邻菲咯啉(phen)形成的蓝色发光配合物。该配合物是典型的配体发光配合物，其发射峰位于444nm，激发波长为334nm和407nm。元素分析、红外光谱、紫外—可见光谱和差热—热重的分析结果表明：配合物中含有大量的N—HPA和相对较少的稀土离子和phen，其中稀土离子与N—PA中的羧酸根配位，而N—PA中的氨基通过氢键与phen的氯原子结合，形成了有利于配体之间的能量传递和电子转移的通道。稀土离子Tb^3 ，Eu^3 的共同存在促进了这一能量转移通道的形成，进而强化了配体的蓝色发射。     

银(Ⅰ)、镉(Ⅱ)4-巯基吡啶配合物的光谱研究

采用常规溶液反应蒸发法以4-巯基吡啶(简写为4-MPy)为有机配体与银、镉的硝酸盐合成了两种金属有机配合物。并利用红外、拉曼、紫外-可见光谱技术对4-MPy及合成的配位化合物进行了研究,对主要红外和拉曼谱带进行了经验归属,并进一步讨论了配体和配合物的特征吸收谱带与配合物结构间的关系。在红外光谱中,配体在1 459cm-1处的吸收峰归属为CC和CN复合振动峰,形成配合物后在两种配合物中,此吸收峰分别向高波数位移至1 464和1 464cm-1。在拉曼光谱中,两种有机配位化合物在1 004和1 008cm-1处归属为环呼吸振动峰、在1 617和1 615cm-1处归属为环伸缩振动峰、在720和720cm-1处归属为β(C—C)和ν(C—S)的复合振动峰,各自十分相似。     

4′-[4-（3吡-啶基）苯基]-2,2′：6′,2″联三吡啶及其金属配合物的光谱

合成了多齿配体4′-[4-（3吡-啶基）苯基]-2,2′：6′,2″-联三吡啶（L）,研究了L与过渡金属（Zn^2＋,Cu^2＋,Co^2＋）形成配合物的紫外可见光谱和荧光发射光谱。结果表明：在95%乙醇溶液中,L的最大吸收峰位于295nm,形成配合物后,在330nm附近出现了新的吸收峰;与L相比,Zn^2＋使L的荧光增强并红移,而Cu^2＋和Co^2＋能够完全猝灭L的荧光。由此可见,L不仅能够与金属离子构建组装体,也可以作为具有潜在应用价值的荧光材料。     

The effect of heat treatment on bistable Ag-TCNQ thin films

The surface chemical state and morphology of as-deposited and post-heat-treated electrical bistable Ag-TCNQ thin films have been investigated with X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM), respectively. The post-heat-treatment process promotes the reaction between Ag and TCNQ to form a complex, and finally Ag-TCNQ films with grain size of 50 nm and surface flatness in nanometer-scale have been obtained. XPS analysis reveals that the bonds between Ag and TCNQ are near cyan ends and cause new state of nitrogen originated by electrons transfer from Ag to TCNQ.     

Electronic absorption and emission spectra of Alq3 in solution with special attention to a delayed fluorescence

Tris(8-quinolinolato)aluminum(III) (Alq₃) shows electronic absorption bands at 378, 360 (in a 1:1 mixed solvent of methanol and ethanol (ME) at 77 K), 334, 316, 300, 263, 255.8, and 233 nm in ethanol at room temperature. According to the polarized fluorescence excitation spectrum together with MO calculations, for instance, the 360 nm band is assigned to an LL CT transition (an intramolecular charge transfer transition between two ligands), and the 378 nm band to an LM/ML CT one (an intramolecular charge transfer transition between ligand and metal). Alq₃ shows a broad fluorescence band peaking at around 478 nm in the ME matrix at 77 K. The emission spectrum measured with a phosphoroscope has two emission bands at 567 and 478 nm. The 567 nm band accompanies vibronic bands at 578 and 605 nm, being safely assigned to a phosphorescence of Alq₃. The lifetimes of the 478 and 567 nm bands are both 5.4 ms. The lifetime of the 478 nm band together with the band position and its band shape indicate that this band can be assigned to a delayed fluorescence.     

纳米氧化锌的IR及其薄膜的UV光谱研究

采用溶胶-凝胶浸渍提拉法制备了纳米氧化锌薄膜。ZnO为六方晶系纤锌矿型,薄膜表面均匀致密,粒径尺寸约为10nm,400℃焙烧后的粉体在451cm-1处出现Zn-O伸缩振动,较体相材料向低波数移动了约29cm-1,膜中ZnO粒子的带边吸收位于363nm,其吸光度值与膜层数间的较好线性关系说明可以将氧化锌溶胶中的纳米粒子较好地转移到基片上。     

一种锌希夫碱配合物的表征及发光性能研究

合成并通过真空升华提纯得到了一种高纯度的希夫碱有机金属配合物水杨醛缩邻苯二胺合锌。通过元素分析、红外光谱、热重-差热曲线、紫外-可见光吸收光谱、荧光发射光谱和光致发光光谱表征了其结构、热稳定性以及能带结构。实验结果表明：水杨醛缩邻苯二胺合锌的玻璃化温度(T_g)高达183 ℃,分解温度为449 ℃; 水杨醛缩邻苯二胺合锌是一种多晶粉末状的发光材料,在紫外光的激发下,在四氢呋喃溶液体系中的荧光发射峰在508 nm处,为蓝绿色荧光,色纯度高,荧光量子效率高,禁带宽度2.62 eV; 利用真空热蒸镀很容易制备高质量薄膜,其发射峰在562 nm处,半高宽为48.5 nm的黄绿光发射。利用水杨醛缩邻苯二胺合锌为发光层制备了黄光有机电致发光器件。     

Electron energy-loss spectroscopy of tetracyanoquinodimethane,TCNQ, tetrathiafulvalene,TTF, and the salt TTF-TCNQ

Energy loss spectra of low energy electrons (ELS) have been obtained for thin solid films of tetracyanoquinodimethane (TCNQ), tetrathiafulvalene (TTF), and the charge transfer salt TTF-TCNQ as a function of incident energy (20 to 100 eV). The incident energy dependence of energy loss features allows the identification of triplet and symmetry forbidden excitations in TCNQ and TTF. The ELS spectrum of TTF-TCNQ is compared with high energy electron loss data to show that the surface of evaporated films of TTF-TCNQ contains 20–50% neutral TCNQ molecules.     

Coadsorption of trimethyl phosphine and thiocyanate on colloidal silver: a SERS study combined with theoretical calculations

The adsorption of trimethyl phosphine (TMP) on colloidal silver has been investigated by means of surface‐enhanced Raman scattering spectroscopy (SERS). On the basis of surface selection rules, it is deduced from the SERS results that TMP adsorbs on silver surface via its P atom. The electron donor effect of TMP can be sensitively probed by the coadsorbed SCN⁻. The Raman wavenumber of νCN of the adsorbed SCN⁻ shifts to lower wavenumbers when TMP is coadsorbed with SCN⁻ and the red shift of C≡N stretching wavenumber is found to increase with increasing surface coverage of TMP. This could be explained in terms of the electron donor effect of TMP. Density functional theory (DFT) calculations further confirm the experimental results that the charge transfer is from TMP to silver surface rather than reversely. Natural bond orbital (NBO) analysis indicates that the red shift of C≡N stretching mode is due the increase of electronic populations of π* orbital of C≡N bond induced by coadsorbed TMP, consequently the C≡N bond is weakened, and the νCN shifts to lower wavenumbers. An NBO analysis also indicates that the conjugated effect between S atom and C≡N bond could easily make the charge transfer from silver surface to C≡N bond. Copyright © 2008 John Wiley & Sons, Ltd.     

含氮氟化类金刚石(FN-DLC)薄膜的研究：(Ⅳ)氮掺杂对薄膜结构的影响

不同条件下，在单晶硅基片上沉积了含氮氟化类金刚石(FN-DLC)薄膜.原子力显微(AFM)形貌显示，掺N后，薄膜变得致密均匀.傅里叶变换吸收红外光谱(FTIR)表明，随着r(r=N₂/［N₂+CF₄+CH₄］)的增大薄膜中C—H键的逐渐减少，C〖FY=,1〗N和C≡N键含量逐渐增加.X射线光电子能谱(XPS)的C1s和N1s峰拟合结果发现，N掺入导致在薄膜中出现β-C₃N₄和a-CN_x(x=1,2,3)成分.Roman散射谱的G峰向高频方向位移和峰值展宽等证明：随着r的增大，薄膜内sp²键态含量增加. 关键词： 氟化类金刚石膜 键结构 氮掺杂     

Synthesis of nanocrystalline CdS thin film by SILAR and their characterization

Cadmium sulphide (CdS) thin film was prepared by successive ion layer adsorption and reaction (SILAR) technique using ammonium sulphide as anionic precursor. Characterization techniques of XRD, SEM, TEM, FTIR and EDX were utilized to study the microstructure of the films. Structural characterization by x-ray diffraction reveals the polycrystalline nature of the films. Cubic structure is revealed from X-ray diffraction and selected area diffraction (SAD) patterns. The particle size estimated using X-ray line broadening method is approximately 7 nm. Instrumental broadening was taken into account while particle size estimation. TEM shows CdS nanoparticles in the range 5–15 nm. Elemental mapping using EFTEM reveals good stoichiometric composition of CdS. Characteristic stretching vibration mode of CdS was observed in the absorption band of FTIR spectrum. Optical absorption study exhibits a distinct blue shift in band gap energy value of about 2.56 eV which confirms the size quantization.