共查询到20条相似文献,搜索用时 15 毫秒
1.
Dr. Yukihiro Yoshida Dr. Mitsuhiko Maesato Dr. Manabu Ishikawa Dr. Yoshiaki Nakano Dr. Takaaki Hiramatsu Prof. Dr. Hideki Yamochi Prof. Dr. Gunzi Saito 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(37):12325-12335
Protonated species of the nucleobase cytosine (C), namely the monoprotonated CH+ and the hemiprotonated CHC+, were used to obtain four charge‐transfer complexes of [Ni(dmit)2] (dmit: 1,3‐dithiole‐2‐thione‐4,5‐dithiolate). Diffusion methods afforded two semiconducting [Ni(dmit)2]? salts; (CH)[Ni(dmit)2](CH3CN) ( 1 ) and (CHC)[Ni(dmit)2] ( 2 ). In salt 1 , the [Ni(dmit)2]? ions with a S=1/2 spin construct a uniform one‐dimensional array along the molecular long axis, and the significant intermolecular interaction along the face‐to‐face direction results in a spin‐singlet ground state. In contrast, salt 2 exhibits the Mott insulating behavior associated with uniform 1D arrays of [Ni(dmit)2]?, which assemble a two‐dimensional layer that is sandwiched between the layers of hydrogen‐bonded CHC+ ribbons. Multiple hydrogen bonds between CHC+ and [Ni(dmit)2]? seem to result in the absence of structural phase transition down to 0.5 K. Electrooxidation of [Ni(dmit)2]? afforded the polymorphs of the [Ni(dmit)2]0.5? salts, (CHC+)[{Ni(dmit)2}0.5?]2 ( 3 and 4 ), which are the first mixed‐valence salts of nucleobase cations with metal complex anions. Similar to 2 , salt 3 contains CHC+ ribbons that are sandwiched between the 2D [Ni(dmit)2]0.5? layers. In the layer, the [Ni(dmit)2]0.5? ions form dimers with a S=1/2 spin and the narrow electronic bandwidth causes a semiconducting behavior. In salt 4 , the CHC+ units form an unprecedented corrugated 2D sheet, which is sandwiched between the 2D [Ni(dmit)2]0.5? layers that involve ring‐over‐atom and spanning overlaps. In contrast to 3 , salt 4 exhibits metallic behavior down to 1.8 K, associated with a wide bandwidth and a 2D Fermi surface. The ability of hydrogen‐bonded CHC+ sheets as a template for the anion radical arrangements is demonstrated. 相似文献
2.
Phosphine exchange of [RuIIBr(MeCOO)(PPh3)2(3‐RBzTh)] (3‐RBzTh=3‐benzylbenzothiazol‐2‐ylidene) with a series of diphosphines (bis(diphenylphosphino)methane (dppm), 1,2‐bis(diphenylphosphino)ethylene (dppv), 1,1′‐bis(diphenylphosphino)ferrocene (dppf), 1,4‐bis(diphenylphosphino)butane (dppb), and 1,3‐(diphenylphosphino)propane (dppp)) gave mononuclear and neutral octahedral complexes [RuBr(MeCOO)(η2‐P2)(3‐RBzTh)] (P2=dppm ( 2 ), dppv ( 3 ), dppf ( 4 ), dppb ( 5 ), or dppp ( 6 )), the coordination spheres of which contained four different ligands, namely, a chelating diphosphine, carboxylate, N,S‐heterocyclic carbene (NSHC), and a bromide. Two geometric isomers of 6 ( 6a and 6 b ) have been isolated. The structures of these products, which have been elucidated by single‐crystal X‐ray crystallography, show two structural types, I and II, depending on the relative dispositions of the ligands. Type I structures contain a carbenic carbon atom trans to the oxygen atom, whereas two phosphorus atoms are trans to bromine and oxygen atoms. The type II system comprises a carbene carbon atom trans to one of the phosphorus atoms, whereas the other phosphorus is trans to the oxygen atom, with the bromine trans to the remaining oxygen atom. Complexes 2 , 3 , 4 , and 6a belong to type I, whereas 5 and 6 b are of type II. The kinetic product 6 b eventually converts into 6a upon standing. These complexes are active towards catalytic reduction of para‐methyl acetophenone by 2‐propanol at 82 °C under 1 % catalyst load giving the corresponding alcohols. The dppm complex 2 shows the good yields (91–97 %) towards selected ketones. 相似文献
3.
Sadafumi Nishihara Dr. Tomoyuki Akutagawa Prof. Daisuke Sato Sadamu Takeda Prof. Shin‐ichiro Noro Dr. Takayoshi Nakamura Prof. 《化学:亚洲杂志》2007,2(9):1083-1090
A solid‐state dynamic supramolecular structure consisting of (anilinium)([18]crown‐6) was arranged as the cation in a salt of [Ni(dmit)2]? (dmit=2‐thioxo‐1,3‐dithiole‐4,5‐dithiolate). With the ammonium moiety of anilinium located within the cavity of [18]crown‐6, a hydrogen‐bonded supramolecular structure is formed, with an orthogonal arrangement between the π plane of anilinium and the mean O6 plane of [18]crown‐6. In this supramolecular cation, both anilinium and [18]crown‐6 act as dynamic units with different rotational modes in the solid state. The uniform stacks of cations form an antiparallel arrangement, thus producing a layer structure. Sufficient space for the 180° flip‐flop motion of the phenyl ring and the rotation of [18]crown‐6 was observed in the cation layer. Thermally activated 180° flip‐flop motions, with a frequency of 6 MHz at room temperature and an activation energy of 31 kJ mol?1, were confirmed by temperature‐dependent 2H NMR spectra of ([D5]anilinium)‐([18]crown‐6)[Ni(dmit)2]. A double‐minimum potential for the molecular rotation of anilinium, with a barrier of approximately 40 kJ mol?1, was indicated by ab initio calculations. The wide‐line 1H NMR spectra indicated a thermally activated rotation of [18]crown‐6 at temperatures above 250 K. Therefore, multiple molecular motions of the 180° flip‐flop motion of the phenyl ring and the rotation of [18]crown‐6 occur simultaneously in the solid state. The temperature‐dependent dielectric constants revealed that the molecular motion of [18]crown‐6, other than the flip‐flop motion, dominates the dielectric response in the measured temperature and frequency range. 相似文献
4.
A series of macrocyclic Ni/Fe/S cluster complexes were synthesized and structurally characterized. The macrocyclic type of (diphosphine)Ni‐bridged double butterfly Fe/S complexes [μ‐SCH2CH2OCH2CH2S‐μ][(μ‐S=CS)Fe2(CO)6]2‐[Ni(diphosphine)] ( 1 – 3 ; diphosphine = dppe, dppv, dppb) were prepared by treatment of the dianion [{μ‐SCH2CH2OCH2CH2S‐μ}{(μ‐CO)Fe2(CO)6}2]2–, generated in situ from Fe3(CO)12, Et3N, and HSCH2CH2OCH2CH2SH with excess CS2 followed by treatment of the resulting dianion [{μ‐SCH2CH2OCH2CH2S‐μ}{(μ‐SC=S)Fe2(CO)6}2]2– with (diphosphine)NiCl2. The three complexes 1 – 3 were characterized by elemental analysis and IR, 1H NMR, and 31P NMR spectroscopy. In addition, the molecular structures of 2 and 3 were established by X‐ray crystallography. 相似文献
5.
BIAN Guo-Qing ZHU Qin-Yu DAI Jie WANG Xin YANG Wei YAN Ze-Min SUN Zhen-Rong MUNAKATA Megumu MAEKAWA Masahiko 《中国化学》2003,21(5):537-543
A new coluster-cracking method to synthesize dithiolate metal complexes was reported and four unsymmetric complexes with formula(Me4N)2[M(Ln)(SPh)2](M=Cd and Zn,L1=dmit=1,3-dithiole-2-thione4-5,dithiolate,L2=dmid=1,3-dithiole-2-one-4,5-dithiolate,SPh=thiophenolate)(1-4)were characterized by elemental analysis,IR,UV NMR spectra and so on.The advantages of this method are summarized in two aspects:(1) the preparation is very convenient;(2) the reaction usually completed giving the product with high pruity.The crystal structure of 1 showed that the bond distances of Cd(Ⅱ)to the sulfur of the thiophenolate group are shorter than those of Cd(Ⅱ)to the sulfur of dmit,so that the thiophenolate group does not be replaced in the reaction and thmixed ligand complexes are the dominant produxts.The dmit complexes showed well third-order NLO properties,but not of the dmid complexes,although dmid is an analogue to dmit. 相似文献
6.
M. T. Duarte V. Gama S. Rabaa I. C. Santos 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(7):m278-m280
The title compound, [Fe(C10H15)2][Ni(C3OS4)2]·C4H8O or [Fe(Cp*)2][Ni(dmio)2]·THF, where [Fe(Cp*)2]+ is the decamethylferrocenium cation, dmio is the 2‐oxo‐1,3‐dithiole‐4,5‐dithiolate dianion and THF is tetrahydrofuran, crystallizes with two independent half‐anion units [one Ni atom is at the centre of symmetry (, , 0) and the other is at the centre of symmetry (, 0, )], one cation unit (located in a general position) and one THF solvent molecule in the asymmetric unit. The crystal structure consists of two‐dimensional layers composed of parallel mixed chains, where pairs of cations alternate with single anions. These layers are separated by sheets of anions and THF molecules. 相似文献
7.
Single‐step oxidative homocoupling of aryl Grignard reagents via Co(II), Ni(II) and Cu(II) Complexes under air
下载免费PDF全文
![点击此处可从《应用有机金属化学》网站下载免费的PDF全文](/ch/ext_images/free.gif)
A simple catalytic system of direct synthesis for the symmetrical biaryls using catalytic amounts of Co(II), Ni(II) and Cu(II) complexes has been developed. The reaction system involves in situ synthesis of Grignard reagents. The complexes, containing bidentate Schiff base and dmit (2‐thioxo‐1,3‐dithiole‐4,5‐dithiolate) ligands, were compatible with diverse functionalities and afford a high yield of biaryls in a single step, proving to be promising catalysts in homocoupling reactions. Atmospheric oxygen is used as an oxidant which renders a green, simple and economical catalytic route. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
8.
Su‐Kyung Lee Kyong‐Soon Shin Dr. Dong‐Youn Noh Prof. Dr. Olivier Jeannin Dr. Frédéric Barrière Dr. Jean‐François Bergamini Dr. Marc Fourmigué Dr. 《化学:亚洲杂志》2010,5(1):169-176
The redox‐active and chelating diphosphine, 3,4‐dimethyl‐3′,4′‐bis(diphenylphosphino)‐tetrathiafulvalene, denoted as P2 , is engaged in a series of platinum complexes, [(P2)Pt(dithiolene)], with different dithiolate ligands, such as 1,2‐benzenedithiolate (bdt), 1,3‐dithiole‐2‐thione‐4,5‐dithiolate (dmit), and 5,6‐dihydro‐1,4‐dithiin‐2,3‐dithiolate (dddt). The complexes are structurally characterized by X‐ray diffraction, together with a model compound derived from bis(diphenylphosphino)ethane, namely, [(dppe)Pt(dddt)] . Four successive reversible electron‐transfer processes are found for the [(P2)Pt(dddt)] complex, associated with the two covalently linked but electronically uncoupled electrophores, that is, the TTF core and the platinum dithiolene moiety. The assignments of the different redox processes to either one or the other electrophore is made thanks to the electrochemical properties of the model compound [(dppe)Pt(dddt)] lacking the TTF redox core, and with the help of theoretical calculations (DFT) to understand the nature and energy of the frontier orbitals of the [(P2)Pt(dithiolene)] complexes in their different oxidation states. The first oxidation of the highly electron‐rich [(P2)Pt(dddt)] complex can be unambiguously assigned to the redox process affecting the Pt(dddt) moiety rather than the TTF core, a rare example in the coordination chemistry of tetrathiafulvalenes acting as ligands. 相似文献
9.
Synthesis,Characterization, and Luminescent Properties of Silver(I) Complexes based on Diphosphine Ligands and 2,9‐Dimethyl‐1,10‐phenanthroline
下载免费PDF全文
![点击此处可从《无机化学与普通化学杂志》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Yang‐Zhe Cui Yuan Yuan Hong‐Liang Han Zhong‐Feng Li Min Liu Qiong‐Hua Jin Yu‐Ping Yang Zhen‐Wei Zhang 《无机化学与普通化学杂志》2016,642(18):953-959
Five mono‐nuclear silver(I) complexes with the ligand 2,9‐dimethyl‐1,10‐phenanthroline, namely [Ag(DPEphos)(dmp)]BF4 ( 1 ), [Ag(DPEphos)(dmp)]CF3SO3 ( 2 ), [Ag(DPEphos)(dmp)]ClO4 ( 3 ), [Ag(DPEphos)(dmp)]NO3 ( 4 ), and [Ag(dppb)(dmp)]NO3 · CH3OH ( 5 ) {DPEphos = bis[2‐(diphenylphosphanyl)phenyl]ether, dppb = 1,2‐bis(diphenylphosphanyl)benzene, dmp = 2,9‐dimethyl‐1,10‐phenanthroline} were characterized by X‐ray diffraction, IR, 1H NMR, 31P NMR and fluorescence spectroscopy. Their terahertz (THz) time‐domain spectra were also studied. In these complexes the silver(I), which is coordinated by two kinds of chelating ligands, adopts four‐coordinate modes to generate mono‐nuclear structures. In complexes 1 , 3 – 5 , offset π ··· π weak interactions exist between the neighboring benzene rings. In the 31P NMR spectra, there exist splitting signals (dd), which can be attributed to the coupling of the 107,109Ag–31P. All the emission peaks of these complexes are attributed to ligand‐centered excited states. 相似文献
10.
Synthesis,Characterization, and Luminescent Properties of Silver(I) Complexes based on Diphosphine Ligands and 6,7‐Dicyanodipyridoquinoxaline
下载免费PDF全文
![点击此处可从《无机化学与普通化学杂志》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Yu Wang Yang‐Zhe Cui Zhong‐Feng Li Min Liu Yu‐Ping Yang Zhen‐Wei Zhang Xiu‐Lan Xin Qiong‐Hua Jin 《无机化学与普通化学杂志》2017,643(20):1253-1261
Five mono‐nuclear silver (I) complexes with 6,7‐dicyanodipyridoquinoxaline ligand, namely {[Ag(DPEphos)(dicnq)]NO3}2 · CH3OH ( 1 ), [Ag(DPEphos)(dicnq)]BF4 · CH3OH ( 2 ), [Ag(XANTphos)(dicnq)]CF3SO3 ( 3 ), {[Ag(XANTphos)(dicnq)]NO3}2 ( 4 ), and [Ag(XANTphos)(dicnq)]ClO4 · CH2Cl2 ( 5 ) {DPEphos = bis[2‐(diphenylphosphanyl)phenyl]ether, dicnq = 6,7‐dicyanodipyridoquinoxaline, XANTphos = 9,9‐dimethyl‐4,5‐bis(diphenylphosphanyl)xanthene} were characterized by X‐ray diffraction, IR, 1H NMR, 31P NMR, fluorescence spectra, and terahertz time‐domain spectra (THz‐TDS). In the five complexes the AgI, which is coordinated by two kinds of chelating ligands, adopts four‐coordinate modes to generate mono‐nuclear structures. The C–H ··· π interactions lead to formation of a 1D infinite chain for complexes 2 and 3 . The crystal packing of complexes 1 and 5 reveal that they form 3D supermolecular network by several pairs of C–H ··· π interactions. The emissions of these complexes are attributed to ligands‐centered [π–π*] transition based on both of the P‐donor and N‐donor ligands. 相似文献
11.
《Journal of Coordination Chemistry》2012,65(1):45-54
Abstract Atmospheric pressure chemical ionization mass spectrometry (APCI–MS) has been utilized in the characterization of two series of platinum dithiolene complexes, (COD)Pt(dt) 1, (COD)–Pt(edt) 2, (COD)Pt(dmid) 3, (COD)Pt(mnt) 4, (COD)Pt(eddo) 5, (COD)Pt(dddt) 6 and (Ph3P)2Pt(dt) 7, (Ph3P)2Pt(edt) 8, (Ph3P)2Pt(dmid) 9, (Ph3P)2Pt(dmit) 10, (Ph3P)2Pt(mnt) 11 (where COD = 1,5–cyclooctadiene, dt = ethane–1,2–dithiolate, edt = ethylene–1,2–dithiolate, dmid = 1,3–dithiole–2–oxo–4,5–dithiolate, dmit = 1,3–dithiole–2–thione–4,5–dithiolate, mnt = maleonitrile–1,2–dithiolate, eddo = 4–(ethylene–1′,2′–dithiolate)–1,3-dithiole–2–one, and dddt = 5,6–dihydro–1,4–dithiin–2,3–dithiolate). The series that contains triphenylphosphine is labile toward the loss of HPPh3 +. In addition, an orthometallated species involving the platinum and triphenylphosphine is identified. A dimer is identified for 2, which is shown to be a product of the experiment and not present in the parent material. In addition, a 1:1 adduct with NH4 + is identified for 4 and 11 where the NH4 + originates from the acid hydrolysis of acetonitrile. Finally, a highly unique ion, Pt+, a bare platinum ion, is observed in all COD complexes indicating that a radical mechanism must accompany the decomposition of the COD complexes during the fragmentation process. 相似文献
12.
Jairo Bordinhão Glaucio B. Ferreira Carolina X.A. da Silva 《Journal of organometallic chemistry》2006,691(8):1598-1605
The synthesis and crystal structures of 4,5-bis[(triorganotin)thiolato]-1,3-dithiole-2-thione, (R3Sn)2(dmit), 1, and 4,5-bis[(triorganotin)thiolato]-1,3-dithiole-2-one, (R3Sn)2(dmio), 2, compounds are reported. Compounds, (1 or 2: R = Ph or cyclohexyl, Cy), have been obtained from reaction of R3SnCl with Cs2dmit or Na2dmio. The presence of the two tin centres in (2: R = Ph) is shown in the 13C NMR spectrum by the couplings of both Sn atoms to the dmio olefinic carbons with J values of 29.4 and 24.7 Hz. The δ119 Sn values for (1: R = Ph) and (2: R = Ph) differ by about 30 ppm, values being −20.7 and −50.1 ppm, respectively, in CDCl3 solution. X-ray structure determinations for (1: R = Ph) and (2: R = Ph or Cy) reveal the compounds to have 4-coordinate, distorted tetrahedral tin centres. The dithiolato ligands, dmit and dmio, act as bridging ligands, in contrast to their chelating roles in R2Sn(dmit) and R2Sn(dmio). A further difference between R2Sn(dmit) and R2Sn(dmio), on one hand, and 1 and 2 on the other, is that intermolecular Sn-S and Sn-O interactions are absent in 1 and 2. However, weak intermolecular hydrogen bonding interactions are found in (1: R = Ph) [C-H?π] and in (2: R = Ph) [C-H?π and C-H?O]. 相似文献
13.
Three series of new Ni/Fe/S cluster complexes have been prepared and structurally characterized. One series of such complexes includes the linear type of (diphosphine)Ni-bridged double-butterfly Fe/S complexes [(μ-RS)(μ-S═CS)Fe(2)(CO)(6)](2)[Ni(diphosphine)] (1-6; R = Et, t-Bu, n-Bu, Ph; diphosphine = dppv, dppe, dppb), which were prepared by reactions of monoanions [(μ-RS)(μ-CO)Fe(2)(CO)(6)](-) (generated in situ from Fe(3)(CO)(12), Et(3)N, and RSH) with excess CS(2), followed by treatment of the resulting monoanions [(μ-RS)(μ-S═CS)Fe(2)(CO)(6)](-)with (diphosphine)NiCl(2). The second series consists of the macrocyclic type of (diphosphine)Ni-bridged double-butterfly Fe/S complexes [μ-S(CH(2))(4)S-μ][(μ-S═CS)Fe(2)(CO)(6)](2)[Ni(diphosphine)] (7-9; diphosphine = dppv, dppe, dppb), which were produced by the reaction of dianion [{μ-S(CH(2))(4)S-μ}{(μ-CO)Fe(2)(CO)(6)}(2)](2-) (formed in situ from Fe(3)(CO)(12), Et(3)N, and dithiol HS(CH(2))(4)SH with excess CS(2), followed by treatment of the resulting dianion [{μ-S(CH(2))(4)S-μ}{(μ-S═CS)Fe(2)(CO)(6)}(2)](2-) with (diphosphine)NiCl(2). However, more interestingly, when dithiol HS(CH(2))(4)SH (used for the production of 7-9) was replaced by HS(CH(2))(3)SH (a dithiol with a shorter carbon chain), the sequential reactions afforded another type of macrocyclic Ni/Fe/S complex, namely, the (diphosphine)Ni-bridged quadruple-butterfly Fe/S complexes [{μ-S(CH(2))(3)S-μ}{(μ-S═CS)Fe(2)(CO)(6)}(2)](2)[Ni(diphosphine)](2) (10-12; diphosphine = dppv, dppe, dppb). While a possible pathway for the production of the two types of novel metallomacrocycles 7-12 is suggested, all of the new complexes 1-12 were characterized by elemental analysis and spectroscopy and some of them by X-ray crystallography. 相似文献
14.
Gang Xue Wen Xu Wentao Yu Qi Fang 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(1):m27-m29
The title compound, (C7H10N)[Ni(C3S5)2] or (Etpy)[Ni(dmit)2] (where Etpy is the N‐ethylpyridinium cation, C7H10N+, and dmit is the 2‐thioxo‐1,3‐dithiole‐4,5‐dithiolate dianion, C3S52−), crystallizes in the P space group with two molecules in the asymmetric unit. The [Ni(dmit)2]− monoanion has a planar D2h conformation, with the central Ni atom and the four coordinated S atoms forming an NiS4 square plane. The six‐membered ring of the Etpy cation also shows good planarity, as expected. There are two main types of disorder in the two Etpy cations. Several short intermolecular interactions are present, such as S⋯S, Ni⋯S and Ni⋯Ni, which help to form the enhanced three‐dimensional structure of the crystal. 相似文献
15.
Nadia M. Comerlato William T. A. Harrison R. Alan Howie John Nicolson Low Alexandre C. Silvino James L. Wardell Solange M. S. V. Wardell 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(2):m105-m108
The title compounds are salts of the general form (Q+)2[Zn(dmit)2]2?, where dmit corresponds to the ligand (C3S5)? present in both and Q+ to the counter‐cations (nBu4N)+ [or C16H36N+] and (Ph4As)+ [or C24H20As+], respectively. In the first case, Zn is in the 4e special positions of space group C2/c and hence the [Zn(dmit)2]2? dianion possesses twofold axial crystallographic symmetry. Including these, there are now 11 known examples of [Zn(dmit)2]2? or its analogues, with O replacing the exocyclic thione S, and [Zn(dmio)2]2? dianions in nine structures with various Q. Comparison of these reveals a remarkable variation in details of the conformation which the dianion may adopt in terms of Zn coordination, equivalence of the Zn—S bond lengths, displacement of Zn from the plane of the ligand and overall dianion shape. 相似文献
16.
《Comptes Rendus de l''Academie des Sciences Series IIB Mechanics Physics Astronomy》1999,2(5-6):329-340
Four 1:1, two-component salts combining the [Ni(dmit)2]− anion (dmit2− = 2-thioxo-1,3-dithiole-4,5-dithiolato) and chiral stilbazolium-based countercations (HPMS+ = 4′-[2-(hydroxymethyl)pyrrolidinyl]-1-methylstilbazolium and MPMS+ = 4′-[2-(methoxy-methyl)pyrrolidinyl]-1-methylstilbazolium), or chiral ferrocenyl-based countercations (2+ = (E)-1-((R)-2-methylferrocenyl)-2-(1-methyl-4-pyridiniumyl)ethene; 3+ = (E)-1-((S)-2-trimethylsilylferrocenyl)-2-(1-methyl-4-pyridiniumyl)ethene) were prepared. Semiconducting behaviour (2·10−4 S·cm−1 measured on compressed pellets for [Ni(dmit)2] (MPMS), for example) is secured by the presence of the [Ni(dmit)2]− anions. The chiral nature of the countercations ensures non-centrosymmetry of the structures (space group P1 for [Ni(dmit)2](2) and [Ni(dmit)2](3), for example). A ubiquitous antiparallel arrangement of the cations, which are thus packed in a pseudo-centrosymmetrical environment, results in almost vanishing second-order susceptibilities χ(2), and therefore zero efficiencies in second harmonic generation. 相似文献
17.
Ferreira GB Hollauer E Comerlato NM Wardell JL 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2008,71(1):215-229
Metal complexes of dmit and related ligands, such as dmio, have been studied extensively over the last few decades: [dmit](2-) = bis(1,3-dithiole-2-thione-4,5-dithiolato); [dmio](2-) = bis(1,3-dithiole-2-one-4,5-dithiolato). While much effort has been placed on determining structural properties, very few vigorous spectroscopic studies of these metal complexes have been undertaken. The spectroscopic features of the infrared, Raman and UV-vis spectra, previously reported, have largely been used to characterize compounds. In particular, many details of the electronic structure are still to be revealed. We now report a detailed analysis of the UV-vis spectra of the [M(dmit)](-1) and [M(dmio)](-1) anions, where M = Sb(III) or Bi(III). Experimental spectra were deconvoluted and analysed by several theoretical methodologies, including ab initio CI, TD and CISD calculations. The results led to the assignments of several MLCT/LMCT bands, occurring between 390 and 300 nm, and the confirmation of metal orbital contributions to the HOMO-LUMO boundary. 相似文献
18.
Sadafumi NishiharaTomoyuki Akutagawa Tatsuo Hasegawa Shigeki FujiyamaToshikazu Nakamura Takayoshi Nakamura 《Journal of solid state chemistry》2002,168(2):661-667
Two polymorphs of monovalent [Ni(dmit)2]− (dmit2−=2-thioxo-1,3-dithiole-4,5-dithiolate) crystals A and B, (anilinium)(18-crown-6)[Ni(dmit)2], were prepared, and the structure and magnetic properties were investigated. In these crystals, the [Ni(dmit)2]− molecules form dimers, which arranged into chains between the supramolecular cation structure (anilinium)(18-crown-6). In crystal A, supramolecular cation formed a regular stack, inducing ladder structure of [Ni(dmit)2], whose magnetism had been well fitted by spin ladder equation with the spin gap of Δ=190 K. Crystal B is ca. 3% more densely packed compared to crystal A. Due to the dense packing, supramolecular cation stack is distorted, which prevented the intermolecular interaction between [Ni(dmit)2]− dimers in direction corresponds to the ladder-leg direction in crystal A. Reflecting the [Ni(dmit)2]− arrangement, crystal B showed a temperature dependence of magnetic susceptibility well reproduced by the singlet-triplet thermal activation model, whose antiferromagnetic exchange interaction (2J) was 140 K. 相似文献
19.
20.
A new electrical conductive crystal PyEt[Ni(dmit)2]2 (dmit = 4,5-dimercapto-1,3-dithiole-2-thione) has been synthesized and its X-ray structure has been determined to be in monoclinic
system, C2/c space group. In PyEt[Ni(dmit)2]2 crystal, the conducting component [Ni(dmit)2]0.5- is face-to-face packed forming molecular column along the c-direction, and these molecular columns are then side-by-side
extended along the a-direction forming a kind of two-dimensional conducting sheet on (010). The measured conductivity at room
temperature along a certain direction on (010) plane is 10 S · cm-1. From 282 to 269 K, the crystal shows metallic behavior but changes to semiconductor below 269 K. Based on the measured crystal
structure and calculated band structure, this conductor-semiconductor phase transformation can be primarily interpreted: The
metallic conductivity is corresponding to the uniform molecular column and the atomic-lattice-chain structure of Ni chain,
while the semi-conductive behavior to staggered molecular column and the atomic-zigzag-chain structure of Ni chain. 相似文献