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Beatriz Ballesteros Dr. Gema de la Torre Dr. Axel Shearer Anita Hausmann M. Ángeles Herranz Dr. Dirk M. Guldi Prof. Tomás Torres Prof. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(1):114-125
A novel series of double‐decker lanthanide(III) bis(phthalocyaninato)–C60 dyads [LnIII(Pc)(Pc′)]–C60 (M=Sm, Eu, Lu; Pc=phthalocyanine) ( 1 a – c ) have been synthesized from unsymmetrically functionalized heteroleptic sandwich complexes [LnIII(Pc)(Pc′)] (Ln=Sm, Eu, Lu) 3 a – c and fulleropyrrolidine carboxylic acid 2 . The sandwich complexes 3 a – c were obtained by means of a stepwise procedure from unsymmetrically substituted free‐base phthalocyanine 5 , which was first transformed into the monophthalocyaninato intermediate [LnIII(acac)(Pc)] and further reacted with 1,2‐dicyanobenzene in the presence of 1,8‐diazabicyclo[5.4.0]undec‐7‐ene (DBU). 1H NMR spectra of the bis(phthalocyaninato) complexes 3 a – c and dyads 1 a – c were obtained by adding hydrazine hydrate to solutions of the complexes in [D7]DMF, a treatment that converts the free radical double‐deckers into the protonated species, that is, [LnIII(Pc)(Pc′)H] and [LnIII(Pc)(Pc′)H]–C60. The electronic absorption spectra of 3 a – c and 1 a – c in THF exhibit typical transitions of free‐radical sandwich complexes. In the case of dyads 1 a – c , the spectra display the absorption bands of both constituents, but no evidence of ground‐state interactions could be appreciated. When the UV/Vis spectra of 3 a – c and 1 a – c were recorded in DMF, typical features of the reduced forms were observed. Cyclic voltammetry studies for 3 a – c and 1 a – c were performed in THF. The electrochemical behavior of dyads 1 a – c is almost the exact sum of the behavior of the components, namely the double‐decker [LnIII(Pc)(Pc′)] and the C60 fullerene, thus confirming the lack of ground‐state interactions between the electroactive units. Photophysical studies on dyads 1 a – c indicate that only after irradiation at 387 nm, which excites both C60 and [LnIII(Pc)(Pc′)] components, a photoinduced electron transfer from the [LnIII(Pc)(Pc′)] to C60 occurs. 相似文献
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Single‐Molecule‐Magnet Behavior in the Family of [Ln(OETAP)2] Double‐Decker Complexes (Ln=Lanthanide,OETAP=Octa(ethyl)tetraazaporphyrin) 下载免费PDF全文
Nelson Giménez‐Agulló Dr. Cristina Sáenz de Pipaón Louis Adriaenssens Dr. Marta Filibian Marta Martínez‐Belmonte Eduardo C. Escudero‐Adán Prof. Pietro Carretta Prof. Pablo Ballester Prof. José Ramón Galán‐Mascarós 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(40):12817-12825
Double‐decker complexes of lanthanide cations can be readily prepared with tetraazaporphyrins (porphyrazines). We have synthesized and characterized a series of neutral double‐decker complexes [Ln(OETAP)2] (Ln=Tb3+, Dy3+, Gd3+, Y3+; OETAP=octa(ethyl)tetraazaporphyrin). Some of these complexes show analogous magnetic features to their phthalocyanine (Pc) counterparts. The Tb3+ and Dy3+ derivatives exhibit single‐molecule magnet (SMM) behavior with high blocking temperatures over 50 and 10 K, respectively. These results confirm that, in double‐decker complexes that involve Tb or Dy, the (N4)2 square antiprism coordination mode has an important role in inducing very large activation energies for magnetization reversal. In contrast with their Pc counterparts, the use of tetraazaporphyrin ligands endows the presented [Ln(OETAP)2] complexes with extraordinary chemical versatility. The double‐decker complexes that exhibit SMM behavior are highly soluble in common organic solvents, and easily processable even through sublimation. 相似文献
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Redox‐Driven Symmetry Change for Terbium(III) Bis(porphyrinato) Double‐Decker Complexes by the Azimuthal Rotation of the Porphyrin Macrocycles 下载免费PDF全文
Dr. Ken‐ichi Yamashita Takayo Yamanaka Naoya Sakata Prof. Dr. Takuji Ogawa 《化学:亚洲杂志》2018,13(13):1692-1698
Molecular structures for three oxidation forms (anion, radical, and cation) of terbium(III) bis(porphyrinato) double‐decker complexes have been systematically studied. We found that the redox state controls the azimuthal rotation angle (φ) between the two porphyrin macrocycles. For [TbIII(tpp)2]n (tpp: tetraphenylporphyrinato, n=?1, 0, and +1), φ decreases at each stage of the oxidation process. The decrease in φ is due to the higher steric repulsion between the phenyl rings on the porphyrin macrocycle and the β hydrogen atoms on the other porphyrin macrocycle, which results from the shorter interfacial distance between the two porphyrin macrocycles. Conversely, φ=45° for both [TbIII(oep)2]?1 and [TbIII(oep)2]0 (oep: octaethylporphyrinato), but φ=36° for [TbIII(oep)2]+1. Theoretical calculations suggest that the smaller azimuthal rotation angle of the cation form is due to the electronic interaction in the doubly oxidized ligand system. 相似文献
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Nature of the Intense Second‐Order Nonlinear Optical Activity: DFT Studies on the Octupolarization of Sandwich‐Type Bis(phthalocyaninato) Yttrium Skeletons 下载免费PDF全文
The periodic octupolar vibrational nature of the electron cloud in sandwich‐type bis(phthalocyaninato) yttrium double‐decker compounds has been revealed on the basis of coupled perturbed density functional theory. This in turn results in an intense hyper‐Rayleigh scattering response and renders the double‐decker skeletons excellent second‐order hyperpolarizability with a maximum value as high as 5.55×106 au (≈105×10?30 esu, theoretical prediction) achieved for the molecular conformation with a rotation angle between two phthalocyanine chromophores of approximately 70°. 相似文献
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Dr. M. Carla Aragoni Dr. Massimiliano Arca Prof. Francesco A. Devillanova Prof. Francesco Isaia Prof. Dr. Vito Lippolis Dr. Anna Pintus 《化学:亚洲杂志》2011,6(1):198-208
The electrochemical, UV/Vis–NIR absorption, and emission‐spectroscopic features of (TBA+)( 1 −) and the corresponding neutral complex 1 were investigated (TBA+=tetrabutylammonium; 1 −=[AuIII(Pyr,H‐edt)2]−; Pyr,H‐edt2−=pyren‐1‐yl‐ethylene‐1,2‐dithiolato). The intense electrochromic NIR absorption (λmax=1432 nm; ε=13000 M −1 cm−1 in CH2Cl2) and the potential‐controlled visible emission in the range 400–500 nm, the energy of which depends on the charge of the complex, were interpreted on the grounds of time‐dependent DFT calculations carried out on the cis and trans isomers of 1 , 1 −, and 1 2−. In addition, to evaluate the nonlinear optical properties of 1 x− (x=0, 1), first static hyperpolarizability values βtot were calculated (βtot=78×10−30 and 212×10−30 esu for the cis isomer of 1 − and 1 , respectively) and compared to those of differently substituted [Au(Ar,H‐edt)2]x− gold dithiolenes [Ar=naphth‐2‐yl ( 2 ), phenyl ( 3 ); x=0, 1]. 相似文献
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Yuexing Zhang Xue Cai Dongdong Qi Ping Yao Yongzhong Bian Dr. Jianzhuang Jiang Prof. 《Chemphyschem》2008,9(5):781-792
The effects of alkyloxy substituents attached to one phthalocyanine ligand of three heteroleptic bis(phthalocyaninato) yttrium complexes Y(Pc)[Pc(α‐OCH3)4] ( 1 ), Y(Pc)[Pc(α‐OCH3)8] ( 2 ), and Y(Pc)[Pc(β‐OCH3)8] ( 3 ), as well as their reduction products {Y(Pc)[Pc(α‐OCH3)4]}? ( 4 ), {Y(Pc)[Pc(α‐OCH3)8]}? ( 5 ), and {Y(Pc)[Pc(β‐OCH3)8]}? ( 6 ) [H2Pc(α‐OCH3)4=1,8,15,22‐tetrakis(methyloxy)phthalocyanine; H2Pc(α‐OCH3)8=1,4,8,11,15,18,22,25‐octakis(methyloxy)phthalocyanine; H2Pc(β‐OCH3)8=2,3,9,10,16,17,23,24‐octakis(methyloxy)phthalocyanine] are studied by DFT calculations. Good consistency is found between the calculated results and experimental data for the electronic absorption, IR, and Raman spectra of 1 and 3 . Introduction of electron‐donating methyloxy groups on one phthalocyanine ring of the heteroleptic double‐deckers induces structural deformation in both phthalocyanine ligands, electron transfer between the two phthalocyanine rings, changes in orbital energy and composition, shift of electronic absorption bands, and different vibrational modes of the unsubstituted and substituted phthalocyanine ligands in the IR and Raman spectra in comparison with the unsubstituted homoleptic counterpart Y(Pc)2. The calculations reveal that incorporation of methyloxy substituents at the nonperipheral positions has greater influence on the structure and spectroscopic properties of bis(phthalocyaninato) yttrium double‐deckers than at the peripheral positions, which increases with increasing number of substituents. Nevertheless, the substituent effect of alkyloxy substituents at one phthalocyanine ligand of the double‐decker on the unsubstituted phthalocyanine ring and on the whole molecule and the importance of the position and number of alkyloxy substituents are discussed. In addition, the effect of reducing 1 – 3 to 4 – 6 on the structure and spectroscopic properties of the bis(phthalocyaninato) yttrium compounds is also discussed. This systemic DFT study is not only useful for understanding the structure and spectroscopic properties of bis(phthalocyaninato) rare earth metal complexes but also helpful in designing and preparing double‐deckers with tunable structure and properties. 相似文献
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Lucia Ambrosio M. Carla Aragoni Dr. Massimiliano Arca Dr. Francesco A. Devillanova Prof. Michael B. Hursthouse Prof. Dr. Susanne L. Huth Dr. Francesco Isaia Prof. Vito Lippolis Prof. Dr. Annalisa Mancini Dr. Anna Pintus Dr. 《化学:亚洲杂志》2010,5(6):1395-1406
The tetrabutylammonium (TBA+) salts of square‐planar monoanionic gold complexes of the unsymmetrically substituted Ar,H‐edt2? 1,2‐dithiolene ligands (Ar,H‐edt2?=arylethylene‐1,2‐dithiolato; Ar=phenyl ( 1 ?), 2‐naphthyl ( 2 ?), and 1‐pyrenyl ( 3 ?)) were synthesized and characterized by spectroscopic and electrochemical methods and the corresponding neutral species ( 1 , 2 , and 3 , respectively) were obtained in CH2Cl2 solution at room temperature by diiodine oxidation. The single‐crystal X‐ray diffraction structural data collected for (TBA+)( 2 ?), supported by DFT theoretical calculations, are consistent with the ene‐1,2‐dithiolate form of the ligand and the AuIII oxidation state. All complexes feature intense near‐IR absorptions (at about 1.5 μm) in their neutral states and Vis‐emitting properties in the 400–550 nm range, the energy of which is controlled by the charge of the complex in the case of the 3 ?/ 3 couple. The spectroscopic and electrochemical features of 1 x? and 2 x? (x=0, 1), both in their cis and trans conformations, were investigated by means of DFT and time‐dependent (TD) DFT calculations. 相似文献
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Dr. Noel Nebra Sonia Ladeira Prof. Laurent Maron Prof. Blanca Martin‐Vaca Dr. Didier Bourissou 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(27):8474-8481
In the course of our investigations on polymetallic complexes derived from 1,3‐bis(thiophosphinoyl)indene (Ind(Ph2P?S)2), we observed original fluxional behavior and report herein a joint experimental/computational study of this dynamic process. Starting from the indenylidene chloropalladate species [Pd{Ind(Ph2P?S)2}Cl]? ( 1 ), the new PdII???RhI hetero‐bimetallic pincer complex [PdCl{Ind(Ph2P?S)2}Rh(nbd)] ( 2 ; nbd=2,5‐norbornadiene) was prepared. X‐ray crystallography and DFT calculations substantiate the presence of a d8???d8 interaction. According to multinuclear variable‐temperature NMR spectroscopic experiments, the pendant {Rh(nbd)} fragment of 2 readily shifts in solution at room temperature between the two edges of the SCS tridentate ligand. To assess the role of the pincer‐based polymetallic structure on this fluxional behavior, the related monometallic Rh complex [Rh{IndH(Ph2P?S)2}(nbd)] ( 3 ) was prepared. No evidence for a metal shift was observed in that case, even at high temperature, thus indicating that inplane pincer coordination to the Pd center plays a crucial role. The previously described PdII???IrI bimetallic complex 4 exhibited fluxional behavior in solution, but with a significantly higher activation barrier than 2 . This finding demonstrates the generality of this metal‐shift process and the strong influence of the involved metal centers on the associated activation barrier. DFT calculations were performed to shed light onto the mechanism of such metal‐shift processes and to identify the factors that influence the associated activation barriers. Significantly different pathways were found for bimetallic complexes 2 and 4 on one hand and the monometallic complex 3 on the other hand. The corresponding activation barriers predicted computationally are in very good agreement with the experimental observations. 相似文献
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Magnetic Anisotropy in “Scorpionate” First‐Row Transition‐Metal Complexes: A Theoretical Investigation 下载免费PDF全文
Dr. Marko Perić Dr. Amador García‐Fuente Dr. Matija Zlatar Prof. Claude Daul Stepan Stepanović Dr. Pablo García‐Fernández Prof. Maja Gruden‐Pavlović 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(9):3716-3726
In this work we have analyzed in detail the magnetic anisotropy in a series of hydrotris(pyrazolyl)borate (Tp?) metal complexes, namely [VTpCl]+, [CrTpCl]+, [MnTpCl]+, [FeTpCl], [CoTpCl], and [NiTpCl], and their substituted methyl and tert‐butyl analogues with the goal of observing the effect of the ligand field on the magnetic properties. In the [VTpCl]+, [CrTpCl]+, [CoTpCl], and [NiTpCl] complexes, the magnetic anisotropy arises as a consequence of out‐of‐state spin–orbit coupling, and covalent changes induced by the substitution of hydrogen atoms on the pyrazolyl rings does not lead to drastic changes in the magnetic anisotropy. On the other hand, much larger magnetic anisotropies were predicted in complexes displaying a degenerate ground state, namely [MnTpCl]+ and [FeTpCl], due to in‐state spin–orbit coupling. The anisotropy in these systems was shown to be very sensitive to perturbations, for example, chemical substitution and distortions due to the Jahn–Teller effect. We found that by substituting the hydrogen atoms in [MnTpCl]+ and [FeTpCl] by methyl and tert‐butyl groups, certain covalent contributions to the magnetic anisotropy energy (MAE) could be controlled, thereby achieving higher values. Moreover, we showed that the selection of ion has important consequences for the symmetry of the ground spin–orbit term, opening the possibility of achieving zero magnetic tunneling even in non‐Kramers ions. We have also shown that substitution may also contribute to a quenching of the Jahn–Teller effect, which could significantly reduce the magnetic anisotropy of the complexes studied. 相似文献
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Qing‐Jiang Pan Dr. Grigory A. Shamov Dr. Georg Schreckenbach Prof. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(7):2282-2290
On the basis of uranyl complexes reacting with a polypyrrolic ligand (H4L), we explored structures and reaction energies of a series of new binuclear uranium(VI) complexes using relativistic density functional theory. Full geometry optimizations on [(UO2)2(L)], in which two uranyl groups were initially placed into the pacman ligand cavity, led to two minimum‐energy structures. These complexes with cation–cation interactions (CCI) exhibit unusual coordination modes of uranyls: one is a T‐shaped ( T ) skeleton formed by two linear uranyls {Oexo?U2?Oendo→U1(?Oexo)2}, and another is a butterfly‐like ( B ) unit with one linear uranyl coordinating side‐by‐side to a second cis‐uranyl. The CCI in T was confirmed by the calculated longest distance and lowest stretching vibrational frequency of U2?Oendo among the four U?O bonds. Isomer B is more stable than T , for which experimental tetrameric analogues are known. The formation of B and T complexes from the mononuclear [(UO2)(H2L)(thf)] ( M ) was found to be endothermic. The further protonation and dehydration of B and T are thermodynamically favorable. As a possible product, we have found a trianglelike binuclear uranium(VI) complex having a O?U?O?U?O unit. 相似文献
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Near‐IR Emitting Iridium(III) Complexes with Heteroaromatic β‐Diketonate Ancillary Ligands for Efficient Solution‐Processed OLEDs: Structure–Property Correlations 下载免费PDF全文
Dr. Sagar Kesarkar Dr. Wojciech Mróz Dr. Marta Penconi Dr. Mariacecilia Pasini Dr. Silvia Destri Dr. Marco Cazzaniga Dr. Davide Ceresoli Prof. Patrizia R. Mussini Dr. Clara Baldoli Dr. Umberto Giovanella Dr. Alberto Bossi 《Angewandte Chemie (International ed. in English)》2016,55(8):2714-2718
Three NIR‐emitting neutral IrIII complexes [Ir(iqbt)2(dpm)] ( 1 ), [Ir(iqbt)2(tta)] ( 2 ), and [Ir(iqbt)2(dtdk)] ( 3 ) based on the 1‐(benzo[b]thiophen‐2‐yl)‐isoquinolinate (iqtb) were synthesized and characterized (dpm=2,2,6,6‐tetramethyl‐3,5‐heptanedionate; tta=2‐thienoyltrifluoroacetonate; dtdk=1,3‐di(thiophen‐2‐yl)propane‐1,3‐dionate). The compounds emit between λ=680 and 850 nm with high luminescence quantum yields (up to 16 %). By combining electrochemistry, photophysical measurements, and computational modelling, the relationship between the structure, energy levels, and properties were investigated. NIR‐emitting, solution‐processed phosphorescent organic light‐emitting devices (PHOLEDs) were fabricated using the complexes. The devices show remarkable external quantum efficiencies (above 3 % with 1 ) with negligible efficiency roll‐off values, exceeding the highest reported values for solution‐processible NIR emitters. 相似文献
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Rungthip Kunthom Takuto Adachi Yujia Liu Nobuhiro Takeda Masafumi Unno Ryoji Tanaka 《化学:亚洲杂志》2019,14(23):4179-4182
Novel polyhedral structures were prepared with a butterfly‐shape composed of oligosiloxane wings and a double‐decker silsesquioxane (DDSQ) body. The compounds were synthesized in two steps from commercially available alkoxysilanes, and their structures were confirmed using spectroscopic methods and X‐ray crystallography. Not like other phenyl‐substituted cage silsesquioxanes, these butterfly cages show very good solubility in common organic solvents. The crystal structures clearly showed their unique features: a larger space with longer siloxane chains and a very flexible framework. Moreover, these compounds are thermally stable with a Td5 (5 % weight loss temperature) over 320 °C. 相似文献
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Experimental and Theoretical Studies on the Magnetic Anisotropy in Lanthanide(III)‐Centered Fe3Ln Propellers 下载免费PDF全文
Dr. Luca Rigamonti Andrea Nava Dr. Marie‐Emmanuelle Boulon Dr. Javier Luzon Prof. Roberta Sessoli Prof. Andrea Cornia 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(34):12171-12180
Compounds [Fe3Ln(tea)2(dpm)6] ( Fe3Ln ; Ln= Tb–Yb, H3tea=triethanolamine, Hdpm=dipivaloylmethane) were synthesized as lanthanide(III)‐centered variants of tetrairon(III) single‐molecule magnets (Fe4) and isolated in crystalline form. Compounds with Ln=Tb–Tm are isomorphous and show crystallographic threefold symmetry. The coordination environment of the rare earth, given by two tea3? ligands, can be described as a bicapped distorted trigonal prism with D3 symmetry. Magnetic measurements showed the presence of weak ferromagnetic Fe ??? Ln interactions for derivatives with Tb, Dy, Ho, and Er, and of weak antiferromagnetic or negligible coupling in complexes with Tm and Yb. Alternating current susceptibility measurements showed simple paramagnetic behavior down to 1.8 K and for frequencies reaching 10000 Hz, despite the easy‐axis magnetic anisotropy found in Fe3Dy , Fe3Er , and Fe3Tm by single‐crystal angle‐resolved magnetometry. Relativistic quantum chemistry calculations were performed on Fe3Ln (Ln=Tb–Tm): the ground J multiplet of Ln3+ ion is split by the crystal field to give a ground singlet state for Tb and Tm, and a doublet for Dy, Ho, and Er with a large admixture of mJ states. Gyromagnetic factors result in no predominance of gz component along the threefold axis, with comparable gx and gy values in all compounds. It follows that the environment provided by the tea3? ligands, though uniaxial, is unsuitable to promote slow magnetic relaxation in Fe3Ln species. 相似文献
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Reactions of pyrazole based ligand and halide bridged arene d6 metal precursors resulted a series of mono and di‐substituted pyrazole based half sandwich d6 metal complexes. In general, they are formulated as [(arene)MLCl2] [M = Ru, arene = benzene ( 1 ), p‐cymene ( 2 ), arene = Cp*, M = Rh ( 3 ) and Ir ( 4 )] and [(arene)ML2Cl] [M = Ru, arene = benzene ( 5 ), p‐cymene ( 6 ), arene = Cp*, M = Rh ( 7 ) and Ir ( 8 )]. All these complexes were characterized by various spectroscopic techniques (IR, 1H NMR, ESI‐MS, and UV/Vis). The molecular structures were confirmed by single‐crystal X‐ray diffraction technique. Spectroscopic studies revealed that complexation i.e., mono‐ and di‐substitution occurred by the ratio‐based reaction between pyrazole ligand and metal precursor through the neutral nitrogen rather than protic nitrogen. In these complexes deprotonation of the protic nitrogen does not occur unlike the other complexes containing pyrazole derivatives, in which the pyrazole ligand is anionic. 相似文献
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《化学:亚洲杂志》2017,12(1):110-115
The mounting evidence supporting the role of metal ions in several diseases has turned metal‐ion chelation therapy into a promising treatment strategy. The design of efficient metal‐binding ligands requires in‐depth knowledge of molecular structure and stability constants of the complexes formed. This paper presents an extensive overview on the stability of zinc(II) and copper(II) complexes of a series of cyclodextrin‐8‐hydroxyquinoline conjugates. In order to explain the differences observed in the stability constants between the metal complexes of the 6‐functionalized and 3‐functionalized cyclodextrin isomers, conformational analysis and DFT simulations were also performed. Molecular simulations allowed us to clarify the binding mode and to explain the differences in the stability constants of the metal complexes of these derivatives. 相似文献
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《Angewandte Chemie (International ed. in English)》2017,56(20):5584-5587
A polycyclic aromatic ligand for site‐selective metal coordination was designed by using DFT calculations. The computational prediction was confirmed by experiments: 2,3,6,7‐tetramethoxy‐9,10‐dimethylanthracene initially reacts with [(C5H5)Ru(MeCN)3]BF4 to give the kinetic product with a [(C5H5)Ru]+ fragment coordinated at the terminal ring, which is then transformed into the thermodynamic product with coordination through the central ring. These isomeric complexes have markedly different UV/Vis spectra, which was explained by analysis of the frontier orbitals. At the same time, the calculations suggest that electrostatic interactions are mainly responsible for the site selectivity of the coordination. 相似文献