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1.
We present the design of fluoro derivatives of B(10)H(14) and Li@B(10)H(14) baskets. A synergistic effect of conical push and inward pull (reported independently in previous lithium nonlinear optical (NLO) complexes) has been explored in these derivatives to achieve a robustly large NLO response and a higher vertical ionization potential. Li@1,3,6,9-F(4)B(10)H(10), Li@6,9-F(2)B(10)H(12), and Li@2,4,6,9-F(4)B(10)H(10) exhibit first hyperpolarizability (β(0)) values as large as 181?624, 133?199, and 32?314 au; their vertical ionization potentials are 6.45, 6.30, and 6.78 eV, respectively. These values are significantly higher than those previously reported in Li-doped fluorocarbon chains at the same MP2/6-31+G* level of theory (Xu, H. L.; Li, Z. R.; Wu, D.; Wang, B. Q.; Li, Y.; Gu, F. L.; Aoki, Y. J. Am. Chem. Soc. 2007, 129, 2967). They also exceed those from our earlier designed Li@B(10)H(14) basket (Muhammad, S.; Xu, H. L.; Liao, Y.; Kan, Y. H.; Su , Z. M. J. Am. Chem. Soc. 2009, 131, 2967). In addition, new quantum chemical calculations of enthalpies of reaction (Δ(r)H°) at 298 K for B(10)H(14) and its lithium/fluoro derivatives highlight the changes in their thermodynamical aspects. The calculated enthalpies of lithiation reactions are -10.04, -11.29, and -13.18 kcal/mol for B(10)H(14), 6,9-F(2)B(10)H(12), and 2,4-F(2)B(10)H(12), respectively, demonstrating a higher probability of fluoro decaboranes for reaction with lithium. The obtained results not only explain the effect of position and number dependence of substituted fluoro atom(s) in B(10)H(14) and Li@B(10)H(14) but also elucidate a synergistic behavior to polarize a lithium excess electron for high NLO responses and vertical ionization potentials.  相似文献   

2.
The second-order nonlinear optical (NLO) properties of the Cp*Co(C(2)H(5))(2)C(2)B(4)H(3)-expanded (metallo)porphyrins (Cp* = C(5)Me(5)) have been investigated by using ab inito RHF and density functional theory (DFT) methods. The investigation shows that the compound with expand porphyrin possesses remarkable large molecular hyperpolarizability β(tot) value, ~414.1 × 10(-30) esu (at LC-ωPBE level), and might be an excellent second-order NLO material. From the character of charge transfer (CT) transition, it indicates that the -Cp*Co(C(2)H(5))(2)C(2)B(4)H(3) acts as an electron donor in this kind of systems. As a result of the redox behavior on expanded (metallo)porphyrin, the redox switching character of the NLO responses for the systems 2a-4a has also been studied. The results show that the β(tot) values of reduced forms are larger than that of neutral ones. Furthermore, the time-dependent DFT calculation illustrates that reduced forms have a significant difference on the CT patterns versus neutral ones. The present investigation provides insight into the comparison with DFT results on estimating first hyperpolarizability and the NLO properties of the series of push-pull compounds.  相似文献   

3.
Density functional theory (DFT) calculations were carried out to investigate the second-order nonlinear optical (NLO) properties of a series of proposed porphyrin-polyoxometalate-based complexes related to [5-(3,5-dimethyl-4-hexamolybdate amino-phenyl-ethynyl)-15-(4-nitrophenyl-ethynyl)porphinato]zinc(II) which have donor-π conjugated bridge-acceptor (D-π-A) configurations. Our calculations show that these species possess considerably large molecular total second-order polarizability (β0), ~2000 × 10?30 esu. Furthermore, it can be seen that {W6O18} exhibits stronger electron-donating ability than {Mo6O18}. And two-dimensional (2D) system with A-π-D-π-A structure might be a promising candidate for NLO materials based on the large β0 (4583.5 × 10?30 esu) and in-plane nonlinear anisotropy.  相似文献   

4.
The interaction of decaborane (B(10)H(14)) with the I(-) ion and the (isoelectronic) Xe atom is investigated using a number of theoretical methods: MP2, CCSD(T), CCSD, spin-orbit CISD, and DFT using the B3LYP, B3PW91, PW91PW91, and PBE0 methods. All non-DFT and some DFT methods agree that B(10)H(14)I(-) is bound by charge-dipole electrostatic forces, charge- and dipole-induced-dipole forces, and dispersion forces, while B(10)H(14)Xe is bound by dipole-induced-dipole forces and dispersion forces. Counterpoise corrections are necessary to obtain reliable results. Relativistic effective core potentials were used for the I, Xe, and B atoms. Basis sets for use with these potentials are discussed as is the question of basis set balance in molecules. We find B(10)H(14)I(-) to be bound by 19.8 kcal/mol and B(10)H(14)Xe by 1.1 kcal/mol, indicating that the charge and polarizability of I(-) play the major role in the interaction energy.  相似文献   

5.
To evidentiate the role of the nature of sulfonate ancillary ligands on the value of the quadratic hyperpolarizability of Zn(II) complexes with stilbazole-like ligands, the second-order nonlinear optical (NLO) properties of [ZnY(2)(4,4'-trans-NC5H4CH=CHC6H4NMe2)2] complexes (Y = CF3SO3, CH3SO3, or p-CH3C6H4SO3) are investigated. By working at relatively high concentrations (>3 x 10(-4) M), the positive effect of the triflate ligand remains unique while, with nonfluorinated sulfonate ligands, the second-order NLO response is comparable to that of the related complexes with acetate or trifluoroacetate as ancillary ligands. However, at dilutions higher than 10(-4) M, all of the sulfonate complexes reach huge quadratic hyperpolarizabilities because of solvolysis with the formation of cationic species such as [ZnY(4,4'-trans-NC5H4CH=CHC6H4NMe2)2]+, characterized by a large second-order NLO response. This view is supported by careful conductivity measurements. The same behavior occurs if 4,4'-trans-NC5H4CH=CHC6H4NMe2 is substituted by 4,4'-trans,trans-NC5H4(CH=CH)2C6H4NMe2.  相似文献   

6.
Guan W  Yang G  Yan L  Su Z 《Inorganic chemistry》2006,45(19):7864-7868
The dipole polarizabilities, second-order polarizabilities, and origin of second-order nonlinear optical (NLO) properties of trisorganotin-substituted beta-Keggin polyoxotungstate [XW9O37(SnR)3](11-n)- (X = P, Si, Ge, R = Ph; X = Si, R = PhNO2, PhCCPh) have been investigated by using time-dependent density functional response theory. This class of organic-inorganic hybrid complexes possesses a remarkably large molecular second-order NLO response, especially for [SiW9O37(SnPhCCPh)3]7- (system 5) with the static second-order polarizability (beta(vec)) computed to be 1569.66 x 10(-30) esu. Thus, these complexes have the possibility to be excellent second-order nonlinear optical materials. Analysis of the major contributions to the beta(vec) value suggests that the charge transfer from the heteropolyanion to the organic segment along the z-axis plays the key role in the NLO response of [XW9O37(SnR)3](11-n)-. The computed beta(vec) values increase as a heavy central heteroatom changes in the order Ge > Si > P. Furthermore, nitro substitution on the aryl segment and the lengthening of organostannic pi-conjugation are more important in enhancing the optical nonlinearity, especially for the latter factor. The present investigation provides important insight into the origin of the NLO properties of trisorganotin-substituted heteropolyoxotungstate.  相似文献   

7.
We report a theoretical study based on density functional theory (DFT) on the geometric and electronic structure, linear optical and second-order nonlinear optical properties of a series of new inorganic-organic hybrid hexamolybdate-organoimido-(car)boranes. By the incorporation of borane/carborane at the end of the phenyl ring of the organoimido segment, the studied systems show excellent nonlinear optical (NLO) response than the organoimido-substituted hexamolybdate. The computed static first hyperpolarizability β(vec) value of [Mo(6)O(18)(NC(8)H(8))(B(12)H(11))](4-) (II) is largest, -167.2 × 10(-30) esu, and a higher β(vec) value of [Mo(6)O(18)(NC(8)H(8))(C(2)B(10)H(11))](2-) (III-2p) is 58.6 × 10(-30) esu. Moreover, the time-dependent (TD)DFT calculation illustrates that the maximum absorption, which is helpful for the large NLO responses, is mainly assigned to the charge transfer (CT) from (car)borane and organoimido segment to the hexamolybdate cluster. The density of density (DOS) calculations further illustrate the excitation from valence orbitals of boron atoms to that of Mo and O atoms in hexamolybdate can be responsible for larger NLO responses. The linear and nonlinear optical properties of species III both vary with the position of the vertex on the carborane. Furthermore, the order of the β(vec) values is consistent with the bathochromic shift of the maximum absorption for our studied systems, and the studied systems show a wider transparency range extending into the entire visible and infrared (IR) region.  相似文献   

8.
Density functional theory (DFT) calculations have been carried out to investigate the switching of the second-order nonlinear optical (NLO) properties of η(5)-monocyclopentadienyliron(II) and ruthenium(II) model complexes presenting 5-(3-(thiophen-2-yl)benzo[c]thiophen-1-yl)thiophene-2-carbonitrile as a ligand. The switching properties were induced by redox means. Both oxidation and reduction stimulus have been considered, and calculations have been performed both for the complexes and for the free benzo[c]thiophene derivative ligand in order to elucidate the role played by the organometallic fragment on the second-order NLO properties of these complexes. B3LYP, CAM-B3LYP, and M06 functionals were used for our calculations. The results show some important structural changes upon oxidation/reduction that are accompanied by significant differences on the corresponding second-order NLO properties. TD-DFT calculations show that these differences on the second-order NLO response upon oxidation/reduction are due to a change in the charge transfer pattern, in which the organometallic iron and ruthenium moieties play an important role. The calculated static hyperpolarizabilities were found to be strongly functional dependent. CAM-B3LYP, however, seems to predict more reliable structural and optical data as well as hyperpolarizabilities when compared to experimental data. The use of this functional predicts that the studied complexes can be viewed as acting as redox second-order NLO switches, in particular using oxidation stimulus. The β(tot) value of one-electron oxidized species is at least ~8.3 times (for Ru complex) and ~5.5 times (for Fe complex) as large as that of its nonoxidized counterparts.  相似文献   

9.
A series of D3 (Fe(II), Ru(II), Zn(II), Hg(II)) and D2d (Cu(I), Ag(I), Zn(II)) octupolar metal complexes featuring different functionalized bipyridyl ligands has been synthesized, and their thermal, linear (absorption and emission), and nonlinear optical (NLO) properties were determined. Their quadratic NLO susceptibilities were determined by harmonic light scattering at 1.91 microm, and the molecular hyperpolarizability (beta0) values are in the range of 200-657 x 10(-30) esu for octahedral complexes and 70-157 x 10(-30) esu for tetrahedral complexes. The octahedral zinc(II) complex 1 e, which contains a 4,4'-oligophenylenevinylene-functionalized 2,2'-bipyridine, exhibits the highest quadratic hyperpolarizability ever reported for an octupolar derivative (lambdamax=482 nm, beta1.91(1 e)=870 x 10(-30) esu, beta0(1 e)=657 x 10(-30) esu). Herein, we demonstrate that the optical and nonlinear optical (NLO) properties are strongly influenced by the symmetry of the complexes, the nature of the ligands (donor endgroups and pi linkers), and the nature of the metallic centers. For example, the length of the pi-conjugated backbone, the Lewis acidity of the metal ion, and the increase of ligand-to-metal ratio result in a substantial enhancement of beta. The contribution of the metal-to-ligand (MLCT) transition to the molecular hyperpolarizability is also discussed with respect to octahedral d6 complexes (M=Fe, Ru).  相似文献   

10.
The dynamic first hyperpolarizabilities of a series of 1,10-phenanthroline Ru(Ⅱ) complexes were carried out using density functional theory(DFT).The results indicate that these complexes have large second-order nonlinear optical(NLO) responses.Specially,complex 6b has a maximal first hyperpolarizability βtot value.The first hyperpolarizabilities can be tuned by changing the ancillary ligand,introducing electron-acceptor group NO2 and/or increasing π-conjugation on phenanthroline.Calculations on absorption spectra demonstrate that the second-order NLO responses of complexes in series a are ascribed to the intraligand charge transfer(ILCT),while the complexes in series b exhibit metal-to-ligand charge transfer(MLCT) and ligand-to-ligand charge transfer(LLCT) transition at relatively low-energy absorptions.  相似文献   

11.
The titanium-catalyzed hydroboration reactions of decaborane with a variety of terminal olefins have been found to result in the exclusive, high-yield formation of monosubstituted decaborane 6-R-B(10)H(13) products, arising from anti-Markovnikov addition of the cage B6-H to the olefin. The titanium-catalyzed reactions are slow, often less than one turnover per hour; however, their high selectivities and yields coupled with the fact that they are simple, one-pot reactions give them significant advantages over the previously reported routes to 6-R-B(10)H(13) compounds. The catalyst also has extended activity with reactions carried out for as long as 13 days, showing little decrease in reactivity, thereby allowing for the production of large amounts of 6-R-B(10)H(13). The titanium-catalyzed reactions of decaborane with the nonconjugated diolefins, 1,5-hexadiene and diallylsilane, were found to give, depending upon reaction conditions and stoichiometries, high yields of either alkenyl-substituted 6-(CH(2)=CH(CH(2))(4))-B(10)H(13) (4) and 6-(CH(2)=CHCH(2)SiMe(2)(CH(2))(3))-B(10)H(13) (5) or linked-cage 6,6'-(CH(2))(6)-(B(10)H(13))(2) (6) and Me(2)Si(6-(CH(2))(3)-B(10)H(13))(2) (7) compounds, respectively. The unique tetra-cage product, Si(6-(CH(2))(3)-B(10)H(13))(4) (8), was obtained by the catalyzed reaction of 4 equiv of decaborane with tetraallylsilane. Sequential use of the titanium catalyst and previously reported platinum catalysts (PtBr(2) or H(2)PtCl(6).6H(2)O with an initiator) provides an efficient pathway to asymmetrically substituted 6-R-9-R'-B(10)H(12) species. The structures of compounds 5, 6, and 8, as well as a platinum derivative, (PSH(+))(2)-commo-Pt-[nido-7-Pt-8-(n-C(8)H(17))B(10)H(11)](2)(2-), of 6-(n-octyl)decaborane have been established by single-crystal crystallographic determinations.  相似文献   

12.
氨基酸桥联手性双卟啉的二阶非线性光学性质研究   总被引:4,自引:0,他引:4  
采用半经验量子化学PM3方法对系列氨基酸桥联双卟啉1, 2, 3, 4及其锌配合物进行了几何结构优化, 并用TDHF/PM3方法计算了其静态二阶非线性光学系数. 计算结果表明, L型-氨基酸桥联双卟啉及其锌配合物具有右手螺旋结构特征. 在电偶极近似下, 不同手性氨基酸侧链基团R对分子的总体二阶非线性光学系数β和βHRS的影响不大, 但对二阶非线性光学系数的手性分量βxyz却有显著影响. βxyz与螺旋结构参数r2ζ/L4成正比关系, 符合手性分子二阶非线性光学响应的单电子螺旋模型理论. β张量分析表明, 此类分子表现为以八极为主、 偶极为辅的多极分子, 卟啉环与锌离子的配位有利于增加二阶非线性光学响应的偶极分量和手性分量βxyz.  相似文献   

13.
7-N,N-Dibutylamino-2-azaphenanthrene (L(3)), 8-N,N-dibutylamino-2-azachrysene (L(4)) and related Ir(i) complexes or alkylated salts show high second-order NLO responses, as determined by the EFISH technique and DFT calculations. L(4) is appealing as building block for NLO active materials due to its unexpected large μβ(1.907)value and its very high thermal stability.  相似文献   

14.
Graphene nanoribbon (GNR) has been used, for the first time, as an excellent conjugated bridge in a donor-conjugated bridge-acceptor (D-B-A) framework to design high-performance second-order nonlinear optical materials. Owing to the unique diradical planar conjugated bridge of GNR, D(NH(2))-GNR-A(NO(2)) exhibits exceptionally large static first hyperpolarizability (β(0)) up to 2.5×10(6) a.u. (22000×10(-30) esu) for H(2)N-(7,3)ZGNR-NO(2) (ZGNR=zigzag-edged GNR), which is about 15 times larger than the recorded value of β(0) (1470×10(-30) esu) for the D-A polyene reported by Blanchard-Desce et al. [Chem. Eur. J. 1997, 3, 1091]. Interestingly, we have found that the size effect of GNR plays a key role in increasing β(0) for the H(2)N-GNR-NO(2) system, in which the width effect of GNR perpendicular to the D-A direction is superior to the length effect along the D-A direction.  相似文献   

15.
Well dispersed ruthenium(0) nanoparticles, stabilized in the ionic liquid agent, trihexyltetradecylphosphonium dodecylbenzenesulfonate, have been successfully prepared via a reduction reaction of the precursor [CpRuCp*RuCp*]PF6 (Cp* = C5Me5). The ruthenium(0) nanoparticles were shown to catalyze the isotope exchange reaction between 10B enriched diborane and natural abundant B10H14 to produce highly 10B enriched (approximately 90%) decaborane(14) products. The ruthenium(0) nanoparticles were characterized by TEM, XRD, and XPS. The 10B enriched decaborane(14) has been analyzed by Raman spectroscopy, NMR, and high-resolution MS.  相似文献   

16.
采用密度泛函理论(DFT)方法对双环金属Ir(III)异腈配合物的非线性光学(NLO)性质进行计算研究。用B3PW91(UB3PW91)(金属原子采用LANL2DZ基组,非金属原子采用6-31G*基组)方法对配合物进行几何结构优化。在优化构型基础上,采用B3PW91(UB3PW91)和B3LYP(UB3LYP)方法计算了配合物的第一超极化率(βtot),并用CAM-B3LYP(UCAM-B3LYP)(金属原子采用LANL2DZ基组,非金属原子采用6-31G**基组)方法模拟配合物的吸收光谱。结果表明,主配体的取代基(R1)和副配体的取代基(R2)对第一超极化率值贡献不大。配合物发生氧化还原反应,电荷转移方式增多,电荷转移程度增大,使βtot值显著增加,其中1a+([(C∧N)2Ir(CNR)2]+(R=CH3))发生氧化反应和还原反应的βtot值分别增大了75倍和144倍。因此,这类双环金属铱(III)异腈配合物的氧化还原反应可以有效地调节其二阶NLO性质。  相似文献   

17.
A second-order nonlinear optical (NLO) molecular switching with redox has been investigated in the present paper. The static first hyperpolarizabilities of 5-(BMes(2))-5'-(NPh(2))-2,2'-bipyridine (BNbpy) containing three-coordinate organoboron, Pt(II) chelate complex Pt(BNbpy)Ph(2), and their reduced forms have been calculated by density functional theory (DFT) combined with the analytic derivatives method. There is an enhancement of static first hyperpolarizabilities in the reduced form according to the calculations. That is, the β(vec) value of one-electron-reduced form is ~7 times as large as that of neutral form BNbpy; the β(vec) values of one- and two-electron-reduced forms are ~3 and ~4 times as large as that of neutral form Pt(BNbpy)Ph(2), respectively. In particular, the β(vec) value of two-electron-reduced form (3)Pt(BNbpy)Ph(2)(2-) is 1349 × 10(-30) esu, ~286 times larger than its neutral form. Moreover, the component β(z) value of the metal chelate complex Pt(BNbpy)Ph(2) is 25 × 10(-30) esu, which is ~14 times as large as that of ligand BNbpy; the corresponding F(-)/CN(-) compounds show a decrease in β(x) values compared with the case of the ligand and Pt(II) complex. Analyses of geometries, density of states (DOS), and time-dependent DFT (TDDFT) calculations reveal that the one-electron reduction promotes the molecular conjugation in the x-axis and intensifies the interaction between the metal Pt(II) and ligand and then results in an enhancement of the static first hyperpolarizability, whereas the binding of F(-)/CN(-) to the B atom turns off the p(π)-π* conjugation and has no effect on the conjugation of bipyridine, which leads to a decreasing β value in the x-axis.  相似文献   

18.
To probe the cooperativity of charge transfer between organoimido and hexamolybdate, and enhance the second-order nonlinear optical (NLO) response of organoimido derivatives of hexamolybdates, electronic structures and second-order NLO properties of a series of charge-transfer covalently bonded organoimido derived hexamolybdate complexes with donor-(π conjugated bridge)-acceptor-(π conjugated bridge)-donor or acceptor-(π conjugated bridge)-donor-(π conjugated bridge)-acceptor structures were studied by density functional theory. Studies show that different combinations of the donor, acceptor, heterocycle, –C≡C– and –N=N– moieties, and orientation of heterocycle remarkably affect the second-order NLO responses. The complexes containing electronic acceptor matched with the direction of charge transfer possess remarkable large molecular second-order polarizabilities. Electronic transitions to crucial excited states show that x-polarized transition, contributed to the off-diagonal second-order polarizabiliy tensor (βzxx), possesses lower excited energy compared with z-polarized transition which accounted for the diagonal second-order polarizabiliy tensor (βzzz) and thus led to the large in-plane nonlinear anisotropy (= βzxxzzz) value, as well as good two-dimensional (2-D) second-order NLO properties. These complexes can be used as excellent 2-D second-order NLO materials from the standpoint of both large β and u values.  相似文献   

19.
The second-order nonlinear optical (NLO) properties of 5,10,15-triphenylcorrole (TPC), 5,10,15,20-tetraphenylporphyrin (TPP) and L-amino acid bridged bis-corroles 1, 2, 3 and 4 have been calculated by using TDHF/PM3 method based on the RHF/6-31G (TPC and TPP) or semiempirical PM3 (1, 2, 3, 4) optimized geometries. Calculation results showed TPC and TPP have C1 and D2h symmetry, respectively when N-H protons are localized on the nitrogen atoms. TPC is the second-order NLO active chromophore due to the cancellation of centrosymmetrical structure and its first hyperpolarizability β increases to 11.524×10-30 esu. Under electrical dipole approximation, β values of bis-corroles 1, 2, 3 and 4 vary from 9.831×10-30 to 14.221×10-30 esu, and no much improvement in the first hyperpolarizability was observed as compared to TPC monomer. However, β values of bis-corroles 1, 2, 3 and 4 are improved by about 4 times as compared to their bis-porphyrin counterparts. The analysis of β components indicates that β of this kind of bis-corroles is mainly contributed from its radial component βr. With the variation of amino acid side chains, βHRS, β, βxyz, βr and βa of bis-corroles change remarkably. Chiral L-amino acid bridged bis-corroles 2, 3 and 4 have a right-handed helix structure, and their chiral component βxyz matches βxyz ∝ r2ζ/L4 (helix parameters), showing the second-order chiral NLO response of these bis-corroles could be described by one-electron helical model theory. It was found that the radial component βr of chiral helix bis-corroles also matches β r ∝ r2ζ/L4.  相似文献   

20.
Unlike in conventional organic solvents where transition metal catalysts are required, decaborane olefin-hydroboration reactions have been found to proceed in biphasic ionic-liquid/toluene mixtures with a wide variety of olefins, including alkyl, alkenyl, halo, phenyl, ether, ester, pinacolborane, ketone, and alcohol-substituted olefins, and these reactions now provide simple high-yield routes to 6-R-B10H13 derivatives. Best results were observed for reactions with bmimX (1-butyl-3-methylimidazolium, X = Cl(-) or BF4(-)) and bmpyX (1-butyl-4-methylpyridinium, X = Cl(-) or BF4(-)). Both the experimental data for these reactions and separate studies of the reactions of B10H13(-) salts with olefins indicate a reaction sequence involving (1) the ionic-liquid-promoted formation of the B10H13(-) anion as the essential initial step, (2) the addition of the B10H13(-) anion to the olefin to form a 6-R-B10H12(-) anion, and finally, (3) protonation of 6-R-B10H12(-) to form the final neutral 6-R-B10H13 product. The 6-R-B10H13 derivatives also undergo ionic-liquid-mediated dehydrogenative alkyne-insertion reactions in biphasic bmimCl/toluene mixtures, and these reactions provide high yield routes to 3-R-1,2-R' 2-1,2-C2B10H9 ortho-carborane derivatives.  相似文献   

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