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1.
采用从头计算MP2和CIS方法分别优化等电子双核d8配合物[Pt2(P2O4H2)4]4-和[Pt2(P2O4CH4)4]4-的基态和激发态结构。结果表明基态Pt-Pt距离分别为0.290 5和0.298 7 nm,与实验的0.292 5和0.298 0 nm符合。NBO计算的Pt-Pt键级以及Pt原子间伸缩振动说明Pt-Pt相互作用具有吸引本质。CIS计算揭示电子激发到Pt-Pt的σ(pz)成键轨道使得相互作用增强。保持激发态几何,含时密度泛函理论(TD-DFT)计算的溶液发射分别为449和475 nm,与实验值512和510 nm接近。  相似文献   

2.
用密度泛函B3LYP方法对3-(3'-吡啶基)-6-芳基-1,2,4-三唑并[3,4-b]-1,3,4-噻二唑衍生物(芳基为苯基、3-吡啶基和苯乙烯基)进行基态几何构型全优化,计算分子的电离势I_p和电子亲和势E_A等相关能量,并用Zerner间略微分重叠(ZINDO)和含时密度泛函(TDDFT)方法计算吸收光谱,用单组态相互作用方法(CIS)优化三种化合物分子的S_1激发态结构,分析其能量与发射光谱的关系,计算溶剂中分子的吸收和发射光谱,并与实验结果对照.计算结果表明,从3-(3'-吡啶基)-6-苯基-1,2,4-三唑并[3,4-b]-1,3,4-噻二唑分子(化合物A)到3-(3'-吡啶基)-6-(3'-吡啶基)-1,2,4-三唑并[3,4-b]-1,3,4-噻二唑分子(化合物B)以及3-(3'-吡啶基)-6-对乙烯苯基-1,2,4-三唑并[3,4-b]- 1,3,4-噻二唑分子(化合物C)的电子亲和势依次增大,愈来愈容易接受电子,吸收光谱和发射光谱红移.  相似文献   

3.
采用从头算Hartree-Fock方法对具有Keggin结构的多金属氧酸盐离子α-[SiW12O40]4-进行优化. 以基态几何为基础, 进行单激发组态相互作用(CIS)计算. 结果表明, WO6单元形成扭曲的八面体, 而SiO4部分仍具有准四面体结构; 阴离子的4个三金属簇W3O13可容纳3~4个负电荷, 从微观结构上揭示了杂多阴离子拥有大量负电荷仍能稳定的原因.  相似文献   

4.
理论研究了离子型配合物[OsN(mnt)2]-[mnt=S2C2(CN)2)]的电子结构和光谱性质, 考察不同配体三价N、二硫氰烯S2C2(CN)2和金属Os的相互作用对光化学性质的影响. 分别在B3LYP/LANL2DZ和CIS/LANL2DZ水平上优化了配合物的基态和激发态结构. 与基态(1A1)相比, 激发态(3A2)的Os≡N 的键长缩短了0.0066 nm, 这与计算得到的频率增大一致, 使用TD-DFT方法计算得到了配合物的吸收和发射光谱. 计算得到的位于300 nm(f=0.1497)和262 nm(f=0.2890)的强吸收都来自1A1→1B1跃迁, 分别指认为SC→Os≡N+CN 和N+SC→Os≡N+CN的电子跃迁. 最低能量的吸收位于446 nm(f=0.0206) 处, 来自1A1→1B2的电子跃迁, 指认为N→Os和 N+SC→CN. 计算得到配合物在气态的磷光发射位于678 nm(A3A2→X1A1)处, 而在丙酮溶液中则蓝移到了625 nm处, 跃迁属性不变, 都是N→Os和S→Os的跃迁.  相似文献   

5.
采用从头算Hartree—Fock方法对具有Keggin结构的多金属氧酸盐离子α-[SiW12O40]^4-进行优化.以基态几何为基础,进行单激发组态相互作用(CIS)计算.结果表明,WO6单元形成扭曲的八面体,而SiO4部分仍具有准四面体结构;阴离子的4个三金属簇W2O13可容纳3~4个负电荷,从微观结构上揭示了杂多阴离子拥有大量负电荷仍能稳定的原因.  相似文献   

6.
李会学  唐惠安  杨声  萧泰 《物理化学学报》2007,23(11):1781-1786
用密度泛函B3LYP方法对3-(3’-吡啶基)-6-芳基-1,2,4-三唑并[3,4-b]-1,3,4-噻二唑衍生物(芳基为苯基、3-吡啶基和苯乙烯基)进行基态几何构型全优化, 计算分子的电离势IP和电子亲和势EA等相关能量, 并用Zerner间略微分重叠(ZINDO)和含时密度泛函(TDDFT)方法计算吸收光谱, 用单组态相互作用方法(CIS)优化三种化合物分子的S1激发态结构, 分析其能量与发射光谱的关系, 计算溶剂中分子的吸收和发射光谱, 并与实验结果对照. 计算结果表明, 从3-(3’-吡啶基)-6-苯基-1,2,4-三唑并[3,4-b]-1,3,4-噻二唑分子(化合物A)到3-(3’-吡啶基)-6-(3’-吡啶基)-1,2,4-三唑并[3,4-b]-1,3,4-噻二唑分子(化合物B)以及3-(3’-吡啶基)-6-对乙烯苯基-1,2,4-三唑并[3,4-b]-1,3,4-噻二唑分子(化合物C)的电子亲和势依次增大, 愈来愈容易接受电子, 吸收光谱和发射光谱红移.  相似文献   

7.
用从头算方法研究[Au(i-mnt)]22-(i-mnt=i-marononitriledithiolate)的电子吸收和磷光发射性质,利用MP2和CIS方法分别优化了[Au(i-mnt)]22-基态和激发态几何结构.计算的基态Au(Ⅰ)—Au(Ⅰ)键长为0.2825nm,表明Au(Ⅰ)之间存在弱吸引作用.采用SCRF方法中IPCM模型模拟配合物在乙氰溶液中的行为,计算得到的最大吸收波长为315.5nm,指认X1Ag→A1Au来源于i-mnt配体内电荷转移跃迁.在436.2nm处得到具有B3Au→1Ag跃迁的磷光发射,指认为i-mnt配体内电荷转移和金属到配体电荷转移跃迁,与500nm乙氰溶液的发射相对应,为金属修饰的有机配体发光机制.  相似文献   

8.
应用TD.DFT(time-dependent density functional theory)并PCMfpolarizable continuum model)模型研究了一类自组装的[Pt2M4(C'≡CH)8](M=Cu,Ag)簇合物的电子结构和光谱性质.应用DFT(density functional theory)方法优化了该簇合物的基态及激发态结构.综合计算结果,得到与试验结果相一致的结构与光谱特点.[Pt2Ag4(C≡CH)8]具有呈D4和D4h对称性的两个稳定的基态几何结构.Pt-M距离预示弱相互作用的存在.Cu—Cu距离大于俩个Cu原子的范德华半径和而Ag-Ag间距与俩个Ag原子的范德华半径和差别不大.激发过程使得Pt…M,Ag…Ag作用增强,虽然Cu…Cu距离也相应缩短,但是其仍大于范德华半径之和.[Pt2Cu4(C≡CH)8]、[Pt2Ag4(C≡CH)8](A)和(B)的最低能吸收在450、365和375nm处,发射在611、431和435nm处.红外可见谱范围内,[Pt2M4(C≡CH)8]的吸收波带都有Cu或Ag成分的贡献,所以没有ILCT或MPtLCT跃迁特征出现(ILCT:intraligand charge transfer;MLCT:metal-to—ligand charge transfer).由于最低能吸收和发射具有不同的跃迁特征,所以发射不是来自于最低能吸收.[Pt2Ag4(C≡CH)8]簇合物的MM相互作用在激发态增强,发射光谱具有显著的ILCT特点,这也是[Pt2Ag4(C≡CH)8]的发射波长相对于其对应的同配体前躯体[Pt(C≡CH)4]^2-有少许蓝移的原因.  相似文献   

9.
化合物[N,N'-二(亚水杨基)-1,2-乙二胺]Pt(Ⅱ)(1)在OLED材料上具有很大的应用潜力, 我们利用密度泛函(DFT/Lanl2dz)方法计算了它的电子结构和光谱性质. 计算结果与实验值符合得很好. 计算结果表明, 该化合物最低能吸收和三态磷光发射均来自于[L(Phenoxide lone pair)→π*(imine)](LLCT: ligand-to-ligand charge transfer)和[Pt(5d)→π*(Schiff base)](MLCT: metal-to-ligand charge transfer)的混合电荷跃迁. 另外, 计算得到了该配合物在气态中的激发态几何结构. 通过在不同的溶液中计算吸收和发射光谱, 发现该化合物没有明显的溶剂化显色效应, 说明溶液极性对光谱的影响不大.  相似文献   

10.
通过NiCl2·6H2O与双齿配体2-(二苯基膦)乙醇(Ph2PCH2CH2OH)或其氧化物2-(二苯基氧膦)乙醇[Ph2P(O)CH2CH2OH]的反应,制得两种结构新颖的阳离子型镍配合物[NiCl(Ph2PCH2CH2OH)2 (H2O)]+Cl-(1)和[Ni(Ph2P(O)CH2CH2OH)4]2+[NiCl4]2-(2).通过元素分析、31P核磁共振及X射线单晶衍射对配合物1和2的结构进行了表征.配合物1的晶体属单斜晶系,C2/c空间群,中心金属Ni具有六配位八面体几何构型.配合物2属四方晶系,I4(1)/a空间群,中心原子Ni与PO基团中的O配位形成平面四边形构型.  相似文献   

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13.
Pan QJ  Fu HG  Yu HT  Zhang HX 《Inorganic chemistry》2006,45(21):8729-8735
The structures of [Pt2(pop)4]4-, [Pt2(pcp)4]4-, and related species [Pt2(pop)4X2]4- and [Pt2(pop)4]2- in the ground states (pop = P2O5H2(2-), pcp = P2O4CH4(2-), and X = I, Br, and Cl) were optimized using the second-order M?ller-Plesset perturbation (MP2) method. It is shown that the Pt-Pt distances decrease in going from [Pt2(pop)4]4- to [Pt2(pop)4X2]4- to [Pt2(pop)4]2-. This is supported by the analyses of their electronic structures. The calculated aqueous absorption spectra at the time-dependent density functional theory (TD-DFT) level agree with experimental observations. The unrestricted MP2 method was employed to optimize the structures of [Pt2(pop)4]4- and [Pt2(pcp)4]4- in the lowest-energy triplet excited states. The Pt-Pt contraction trend is well reproduced in these calculations. For [Pt2(pop)4]4-, the Pt-Pt distance decreases from 2.905 A in the ground state to 2.747 A in the excited state, which is comparable to experimental values of 2.91-2.92 A and 2.64-2.71 A, respectively. On the basis of the excited-state structures of such complexes, TD-DFT predicts the solution emissions at 480 and 496 nm, which is closer to the experimental values of 512 and 510 nm emissions, respectively.  相似文献   

14.
We have synthesized two forms of erbium tetracyanoplatinates, Er2[Pt(CN)4]3.21H2O (red form) and Er2[Pt(CN)4]2.SO4.11.5H2O (yellow form), and determined their crystal structures by X-ray diffraction. While the red form crystallizes in the orthorhombic space group Pbcn, with a = 15.4848(3) A, b = 13.8186(2) A, c = 19.07820(10) A, alpha = beta = gamma = 90 degrees, and Z = 4, the yellow form precipitates in the tetragonal space group I4cm, with a = b = 14.321(2) A, c = 13.338(3) A, alpha = beta = gamma = 90 degrees, and Z = 4. Both forms show [Pt(CN)4]2- chains but differ markedly in color and morphology. This is due to the incorporation of sulfate ions in the latter modification, leading to an increased Pt-Pt distance. The observed optical absorption and emission behavior of the title compounds is correlated with the Pt-Pt distances.  相似文献   

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Synthesis and Structure of the Platinum(0) Compounds [(dipb)Pt]2(COD) and (dipb)3Pt2 and of the Cluster Hg6[Pt(dipb)]4 (dipb = (i-Pr)2P(CH2)4P(i-Pr)2) The reduction of (dipb)PtCl2 with Na/Hg yields (dipb)Pt as an intermediate which reacts with the amalgam to form the cluster Hg6[Pt(dipb)]4 ( 3 ) or decomposes to (dipb)3Pt2 ( 2 ) and Pt. In the presence of COD [(dipb)Pt]2(COD) ( 1 ) is obtained. 1 crystallizes monoclinicly in the space group P21/c with a = 1596.1(4), b = 996.5(2), c = 1550.4(3) pm, β = 113.65(2)°, Z = 2. In the dinuclear complex two (dipb)Pt units are bridged by a 1,2-η2-5,6-η2 bonded COD ligand. Whereby the C = C double bonds are lengthened to 145 pm. 2 forms triclinic crystals with the space group P1 and a = 1002.0(2), b = 1635.9(3), c = 868.2(2) pm, α = 94.70(2)°, β = 94.45(2)°, σ = 87.95(1)°, Z = 1. In 2 two (dipb)Pt moieties are connected by a μ-dipb ligand in a centrosymmetrical arrangement. 3 is monoclinic with the space group C2/c and a = 1273.8(3), b = 4869.2(6), c = 1660.2(3) pm, β = 95.16(2)°, Z = 4. The clusters Hg6[Pt(dipb)]4 have the symmetry C2. Central unit is a Hg6 octahedron of which four faces are occupied by Pt(dipb) groups. The bonding in the cluster is discussed on the basis of eight Pt? Hg two center bonds of 267.6 pm and two Pt? Hg? Pt three center bonds with Pt? Hg = 288.0 pm.  相似文献   

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Dynamic NMR experiments on trans-[Pt(Cl)(PHCy2)2[P(X)Cy2]]z where X is a lone pair (1, z = 0), H (2, z = +1), S (3, z = 0), or O (4, z = 0) show that the rotation around the P(X)-Pt bond is hindered for all molecules studied, with deltaG++ ranging from 8.2 to 11.0 kcal/mol. The highest value of the series was calculated for trans-[Pt(Cl)(PHCy2)2[P(O)Cy2]] (4) where intramolecular P=O...H-P interactions act as a molecular brake at room temperature. Single-crystal X-ray diffraction confirms the presence of both intra and intermolecular P=O...H interactions in solid 4. In the case of [Pt(Cl)(PHCy2)3]Cl, multinuclear NMR analysis indicates the presence of a P-H...Cl- interaction in aromatic or halogenated solvents which could have also a minor effect on the rotational barrier around the P(X)-Pt bond.  相似文献   

19.
On Formation of Arsenatephosphates Pb[H2(As, P)O4]2 and PbH(As, P)O4 and the Distribution of As and P at the Anion Positions in Pb[H2(As, P)O4]2 Arsenatephosphates Pb[H2(As, P)O4]2 and PbH(As, P)O4 were prepared and characterized by chemical analysis and X-ray investigations. The observed linear dependence between unit cell parameters and the As/P-contents points to the existence of a complete range of mixed crystals as well between Pb(H2PO4)2 and Pb(H2AsO4)2 as between PbHPO4 and PbHAsO4. The occupation of the anion sites in Pb[H2(As, P)O4]2 by AsO4 and PO4 has been determined by X-ray structure analysis. The calculated occupation factors and the mean bond distances in the anions of the two sites showed, that there exists a slight preference for As to go into site P, As(1).  相似文献   

20.
Crystal Structures of the Azido Platinates (AsPh4)2[Pt(N3)4] and (AsPh4)2[Pt(N3)6] The crystal structures of the two homoleptic azido platinates (AsPh4)2[Pt(N3)4] ( 1 ) and (AsPh4)2[Pt(N3)6] ( 2 ) were determined by X‐ray diffraction at single crystals. In 1 the [Pt(N3)4]2– ions are without crystallographic site‐symmetry, and the platinum atoms show a planar surrounding. The [Pt(N3)6]2– ions in 2 are centrosymmetric (Ci) with an octahedral surrounding at the platinum atoms. While 1 is highly explosive, 2 is of significantly greater stability. This behaviour is explained by the packing conditions. 1 : Space group P21/n, Z = 6, lattice dimensions at –80 °C: a = 1045.3(1), b = 1620.2(1), c = 4041.0(3) pm; β = 96.70(1)°; R1 = 0.0654. 2 : Space group P1, Z = 1, lattice dimenstions at –80 °C: a = 1027.6(1), b = 1049.1(2), c = 1249.9(3) pm; α = 88.27(1)°, β = 74.13(1)°, γ = 67.90(1)°; R1 = 0.0417.  相似文献   

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