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1.
Hirotaka Mori Taeyeon Kim Prof. Dr. Dongho Kim Prof. Dr. Atsuhiro Osuka 《化学:亚洲杂志》2016,11(9):1454-1463
New hybrid porphyrin tapes comprising meso‐3,5‐di‐tert‐butylphenyl‐substituted ZnII‐porphyrins ( D ) and meso‐pentafluorophenyl‐substituted ZnII‐porphyrins ( A ) were synthesized via cross‐condensation of meso‐formyl porphyrins 1 , 5 , and 9 with oligopyrromethanes 2 and 6 as key steps. These hybrid tapes exhibit improved solubilities and enhanced chemical stability as compared with original Dn porphyrin tapes, and all display remarkably coplanar structures favorable for π‐conjugation. The absorption spectrum of ADDA displays Q‐like bands at 1400 and 1657 nm with a vibronic structure characteristic of porphyrinoids. The cyclic voltammograms exhibited positively shifted oxidation and reduction waves in the order of DDD < DAD < ADA < AAA . Tetrameric tape ADDA displays five reversible waves in a narrow range of 1.13 V. Two‐photon absorption (TPA) measurement confirmed that the π‐conjugation path is extended from 12 to ADDA and the molecular polarizability of ADA is larger than that of AAA . 相似文献
2.
Olha Sereda Helen Stoeckli‐Evans 《Acta Crystallographica. Section C, Structural Chemistry》2008,64(6):m221-m223
The structure of the title compound, [NiCu(CN)4(C10H8N2)(H2O)2]n or [{Cu(H2O)2}(μ‐C10H8N2)(μ‐CN)2{Ni(CN)2}]n, was shown to be a metal–organic cyanide‐bridged framework, composed essentially of –Cu–4,4′‐bpy–Cu–4,4′‐bpy–Cu– chains (4,4′‐bpy is 4,4′‐bipyridine) linked by [Ni(CN)4]2− anions. Both metal atoms sit on special positions; the CuII atom occupies an inversion center, while the NiII atom of the cyanometallate sits on a twofold axis. The 4,4′‐bpy ligand is also situated about a center of symmetry, located at the center of the bridging C—C bond. The scientific impact of this structure lies in the unique manner in which the framework is built up. The arrangement of the –Cu–4,4′‐bpy–Cu–4,4′‐bpy–Cu– chains, which are mutually perpendicular and non‐intersecting, creates large channels running parallel to the c axis. Within these channels, the [Ni(CN)4]2− anions coordinate to successive CuII atoms, forming zigzag –Cu—N[triple‐bond]C—Ni—C[triple‐bond]N—Cu– chains. In this manner, a three‐dimensional framework structure is constructed. To the authors' knowledge, this arrangement has not been observed in any of the many copper(II)–4,4′‐bipyridine framework complexes synthesized to date. The coordination environment of the CuII atom is completed by two water molecules. The framework is further strengthened by O—H...N hydrogen bonds involving the water molecules and the symmetry‐equivalent nonbridging cyanide N atoms. 相似文献
3.
Tanaka T Lee BS Aratani N Yoon MC Kim D Osuka A 《Chemistry (Weinheim an der Bergstrasse, Germany)》2011,17(51):14400-14412
Hybrid porphyrin tapes 3 and 4 , consisting of a mixture of 3,5‐di‐tert‐butylphenyl‐substituted donor‐type ZnII–porphyrins and pentafluorophenyl‐substituted acceptor‐type ZnII–porphyrins, were prepared by a synthetic route involving cross‐condensation reaction of a NiII–porphyrinyldipyrromethane and pentafluorophenyldipyrromethane with pentafluorobenzaldehyde followed by appropriate demetalation, remetalation, and oxidative ring‐closure reaction. The NiII‐substituted porphyrin tapes 5 (Ni‐Zn‐Ni) and 6 (Ni‐H2‐Ni) were also prepared through similar routes. The hybrid porphyrin tapes 3 and 4 are more soluble and more stable than normal porphyrin tapes 1 and 2 consisting of only donor‐type ZnII–porphyrins. The solid‐state and crystal packing structures of 3 , 4 , and 5 were elucidated by single‐crystal X‐ray diffraction analysis. Singly meso–meso‐linked hybrid porphyrin arrays 12 and 14 exhibit redox potentials that roughly correspond to each constituent porphyrin segments, while the redox potentials of the hybrid porphyrin tapes 3 and 4 are positively shifted as a whole. The two‐photon absorption (TPA) values of 1–6 were measured by using a wavelength‐scanning open aperture Z‐scan method and found to be 1900, 21 000, 2200, 27 000, 24 000, and 26 000 GM, respectively. These results illustrate an important effect of elongation of π‐electron conjugation for the enhancement of TPA values. The hybrid porphyrin tapes show slightly larger TPA values than the parent ones. 相似文献
4.
Yupeng Li Hai Xu Linyan Wu Feng He Fangzhong Shen Linlin Liu Bing Yang Yuguang Ma 《Journal of Polymer Science.Polymer Physics》2008,46(12):1105-1113
Poly[2‐(2′‐ethylhexyloxy)‐5‐methoxy‐1,4‐phenylene‐(1‐cyanovinylene)] MEH‐CN‐PPV and its all‐trans model compound 1,4‐bis(α‐cyanostyryl)‐2‐(2‐ethylhexyloxy)‐5‐methyloxybenzene were synthesized via Knoevenagel condensation. All‐cis isomer and cis–trans isomer of 1,4‐bis(α‐cyanostyryl)‐2‐(2‐ethylhexyloxy)‐5‐methyloxybenzene were prepared by the photoisomerization reaction. Comparison of the 1H NMR spectra between MEH‐CN‐PPV and three model compounds proved the occurrence of cis‐vinylene in the backbone of MEH‐CN‐PPV. According to the ratio between the cis‐vinylene signal and trans‐vinylene signal, the content of the cis‐vinylene could be estimated to be 15% in MEH‐CN‐PPV. This large cis‐vinylene content came from the rapid photochemical isomerization of cyanovinylene and was likely relative to the poor electroluminescence property of MEH‐CN‐PPV. © 2008 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 46: 1105–1113, 2008 相似文献
5.
Liang Shen Hua‐Tong Wang Yi‐Jian Zhang Zhi‐Min Jin 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(4):m180-m182
The bimetallic title complex, [CuFe(CN)5(C12H30N6O2)(NO)] or [Cu(L)Fe(CN)5(NO)] [where L is 1,8‐bis(2‐hydroxyethyl)‐1,3,6,8,10,13‐hexaazacyclotetradecane], has a one‐dimensional zigzag polymeric –Cu(L)–NC–Fe(NO)(CN)3–CN–Cu(L)– chain, in which the CuII and FeII centres are linked by two CN groups. In the complex, the CuII ion is coordinated by four N atoms from the L ligand [Cu—N(L) = 1.999 (2)–2.016 (2) Å] and two cyanide N atoms [Cu—N = 2.383 (2) and 2.902 (3) Å], and has an elongated octahedral geometry. The FeII centre is in a distorted octahedral environment, with Fe—N(nitroso) = 1.656 (2) Å and Fe—C(CN) = 1.938 (3)–1.948 (3) Å. The one‐dimensional zigzag chains are linked to form a three‐dimensional network via N—H⋯N and O—H⋯N hydrogen bonds. 相似文献
6.
Kenichi Kato Keisuke Fujimoto Prof. Dr. Hideki Yorimitsu Prof. Dr. Atsuhiro Osuka 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(39):13522-13525
Silylation of peripherally lithiated porphyrins with silyl electrophiles has realized the first synthesis of a series of directly silyl‐substituted porphyrins. The meso‐silyl group underwent facile protodesilylation, whereas the β‐silyl group was entirely compatible with standard work‐up and purification on silica gel. The meso‐silyl group caused larger substituent effects to the porphyrin compared with the β‐silyl group. Silylation of β‐lithiated porphyrins with 1,2‐dichlorodisilane furnished β‐to‐β disilane‐bridged porphyrin dimers. A doubly β‐to‐β disilane‐bridged NiII‐porphyrin dimer was also synthesized from a β,β‐dilithiated NiII‐porphyrin and characterized by X‐ray crystallographic analysis to take a steplike structure favorable for interporphyrinic interaction. Denickelation of β‐silylporphyrins was achieved upon treatment with a 4‐tolylmagnesium bromide to yield the corresponding freebase porphyrins. 相似文献
7.
Coverage‐ and Temperature‐Dependent Metalation and Dehydrogenation of Tetraphenylporphyrin on Cu(111) 下载免费PDF全文
Michael Röckert Matthias Franke Quratulain Tariq Stefanie Ditze Michael Stark Patrick Uffinger Daniel Wechsler Upendra Singh Dr. Jie Xiao Dr. Hubertus Marbach Prof. Dr. Hans‐Peter Steinrück Dr. Ole Lytken 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(29):8948-8953
Using temperature‐programmed desorption, supported by X‐ray photoelectron spectroscopy and scanning tunneling microscopy, a comprehensive overview of the main reactions of 5,10,15,20‐tetraphenyl‐21H,23H‐porphyrin (2HTPP) on Cu(111) as a function of coverage and temperature is obtained. Three reactions were identified: metalation with Cu substrate atoms, stepwise partial dehydrogenation, and finally complete dehydrogenation. At low coverage the reactions are independent of coverage, but at higher coverage metalation becomes faster and partial dehydrogenation slower. This behavior is explained by a weaker interaction between the iminic nitrogen atoms and the Cu(111) surface in the high‐coverage checkerboard structure, leading to faster metalation, and the stabilizing effect of T‐type interactions in the CuTPP islands formed at high coverage after metalation, leading to slower dehydrogenation. Based on the amount of hydrogen released and the appearance in STM, a structure of the partially dehydrogenated molecule is suggested. 相似文献
8.
Keisuke Fujimoto Juwon Oh Prof. Dr. Hideki Yorimitsu Prof. Dr. Dongho Kim Prof. Dr. Atsuhiro Osuka 《Angewandte Chemie (International ed. in English)》2016,55(9):3196-3199
Mono‐ and bis(diphenylborane)‐fused porphyrins were synthesized from the corresponding β‐(2‐trimethylsilylphenyl)‐substituted porphyrins through the sequence of Si–B exchange reaction, intramolecular bora‐Friedel–Crafts reaction, and ring‐closing Si–B exchange reaction. Effective electronic interactions of the empty p‐orbital of the boron atom with the porphyrin π‐circuit lead to red‐shifted absorption spectra and substantially decreased LUMO energy levels. Pyridine adds at the boron center to cause disruption of the electronic interaction of the boron atom with large association constants (1.9–17×104 m ?1) depending on the central metal at the porphyrin. The ZnII complex behaved as a hetero‐dinuclear Lewis acid, exhibiting regioselective binding of pyridines at the boron or the zinc center. 相似文献
9.
meso‐Tetraarylporphyrinato complexes 1a – g (ZnII, CuII, and NiII) bearing one or two nitro‐substituted aryl moieties react with 1,1,1‐trimethylhydrazinium iodide in the presence of tBuOK in THF at 0–5° or in the presence of KOH in DMSO at 60–70° according to a nucleophilic substitution of an H‐atom, thus affording porphyrins 2a – g and 3f , g with amino‐functionalized meso‐positioned aryl substituents in yields up to 73% (Scheme 1 and Table). The products obtained are attractive intermediates for further derivatization of porphyrins and may be of potential use as sensitizers in photodynamic cancer therapy. 相似文献
10.
Juan Forniés Violeta Sicilia Pilar Borja José M. Casas Alvaro Díez Elena Lalinde Carmen Larraz Antonio Martín M. Teresa Moreno 《化学:亚洲杂志》2012,7(12):2813-2823
The neutral compounds [Pt(bzq)(CN)(CNR)] (R=tBu ( 1 ), Xyl ( 2 ), 2‐Np ( 3 ); bzq= benzoquinolate, Xyl=2,6‐dimethylphenyl, 2‐Np=2‐napthyl) were isolated as the pure isomers with a trans‐Cbzq,CNR configuration, as confirmed by 13C{1H} NMR spectroscopy in the isotopically marked [Pt(bzq)(13CN)(CNR)] (R=tBu ( 1′ ), Xyl ( 2′ ), 2‐Np ( 3′ )) derivatives (δ13CCN≈110 ppm; 1J(Pt,13C)≈1425 Hz]. By contrast, complex [Pt(bzq)(C≡CPh)(CNXyl)] ( 4 ) with a trans‐Nbzq,CNR configuration, has been selectively isolated from [Pt(bzq)Cl(CNXyl)] (trans‐Nbzq,CNR) using Sonogashira conditions. X‐ray diffraction studies reveal that while 1 adopts a columnar‐stacked chain structure with Pt–Pt distances of 3.371(1) Å and significant π???π interactions (3.262 Å), complex 2 forms dimers supported only by short Pt???Pt (3.370(1) Å) interactions. In complex 4 the packing is directed by weak bzq???Xyl and bzq???C≡E (C, N) interactions. In solid state at room temperature, compounds 1 and 2 both show a bright red emission (?=42.1 % 1 , 57.6 % 2 ). Luminescence properties in the solid state at 77 K and concentration‐dependent emission studies in CH2Cl2 at 298 K and at 77 K are also reported for 1 , 1·CHCl3 , 2 , 2' , 2·CHCl3 , 3 , 4 . 相似文献
11.
Selective Endo and Exo Binding of Mono‐ and Ditopic Ligands to a Rhomboidal Diporphyrin Prism 下载免费PDF全文
Dr. Govindasamy Jayamurugan Derrick A. Roberts Dr. Tanya K. Ronson Prof. Jonathan R. Nitschke 《Angewandte Chemie (International ed. in English)》2015,54(26):7539-7543
Copper(I) can preferentially form heteroleptic complexes containing two phosphine and two nitrogen donors due to steric factors. This preference was employed to direct the self‐assembly of a porphyrin‐faced rhomboidal prism having two parallel tetrakis(4‐iminopyridyl)porphyrinatozinc(II) faces linked by eight 1,4‐bis(diphenylphosphino)benzene pillars. The coordination preferences of the CuI ions and geometries of the ligands come together to generate a slipped‐cofacial orientation of the porphyrinatozinc(II) faces. This orientation enables selective encapsulation of 3,3′‐bipyridine (bipy), which bridges the ZnII ions of the parallel porphyrins, whereas 4,4′‐bipy exhibits weaker external coordination to the porphyrin faces. Reaction with 2,2′‐bipy, by contrast, results in the displacement of the tetratopic porphyrin ligand and formation of [{(2,2′‐bipy)CuI}2(diphosphine)2]. The differing strengths of interactions of bipyridine isomers with the system allows for a hierarchy to be deciphered, whereby 4,4′‐bipy may be displaced by 3,3′‐bipy, which in turn is displaced by 2,2′‐bipy. 相似文献
12.
Jureepan Piromchom Nanthawat Wannarit Chaveng Pakawatchai Sujittra Youngme 《Acta Crystallographica. Section C, Structural Chemistry》2013,69(10):1136-1139
In the title complex, [Ag2Cd(CN)4(C12H12N2)2]·H2O or cis‐[Cd{Ag(CN)2}2(5,5′‐dmbpy)2]·H2O, where 5,5′‐dmbpy is 5,5′‐dimethyl‐2,2′‐bipyridyl, the asymmetric unit consists of a discrete neutral [Cd{Ag(CN)2}2(5,5′‐dmbpy)2] unit and a solvent water molecule. The CdII cation is coordinated by two bidentate chelate 5,5′‐dmbpy ligands and two monodentate [AgI(CN)2]− anions, which are in a cis arrangement around the CdII cation, leading to an octahedral CdN6 geometry. The overall structure is stabilized by a combination of intermolecular hydrogen bonding, and AgI...AgI and π–π interactions, forming a three‐dimensional supramolecular network. 相似文献
13.
Rohit Deshpande Bo Wang Lin Dai Lin Jiang Prof. C. Scott Hartley Prof. Shouzhong Zou Prof. Hong Wang Prof. Lei Kerr 《化学:亚洲杂志》2012,7(11):2662-2669
New opp‐dibenzoporphyrins were prepared in a concise method that was based on a Pd0‐catalyzed cascade reaction. These porphyrins, which contained carboxylic‐acid linker groups on benzene rings that were fused to the porphyrin at their β,β′‐positions, were examined as sensitizers for dye‐sensitized solar cells for the first time. Whereas all of the porphyrins showed solar‐energy‐to‐electricity conversion, an opp‐dibenzoporphyrin with conjugated carboxylic‐acid linkers displayed the highest conversion efficiency and an exceptionally high Jsc value. Cyclic voltammetry of these porphyrins suggested that the fusion of two aromatic benzene rings onto the periphery of the porphyrin lowered the HOMO–LUMO energy gap; the incorporation of a conjugated carboxylic‐acid linker group decreased the HOMO–LUMO gap even further. These CV data are consistent with DFT calculations for these porphyrins and agree well with the UV/Vis absorption‐ and fluorescence spectra of these porphyrins. 相似文献
14.
Chihiro Maeda Pyosang Kim Sung Cho Jong Kang Park Jong Min Lim Dongho Kim Prof. Dr. Josh Vura‐Weis Michael R. Wasielewski Prof. Dr. Hiroshi Shinokubo Prof. Dr. Atsuhiro Osuka Prof. Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(17):5052-5061
meso‐Triazolyl‐appended ZnII–porphyrins were readily prepared by CuI‐catalyzed 1,3‐dipolar cycloaddition of benzyl azide to meso‐ethynylated ZnII–porphyrin (click chemistry). In noncoordinating CHCl3 solvent, spontaneous assembly occurred to form tetrameric array ( 3 )2 from meso–meso‐linked diporphyrins 3 , and dodecameric porphyrin squares ( 4 )4 and ( 5 )4 from the L ‐shaped meso–meso‐linked triporphyrins 4 and 5 . The structures of these assemblies were examined by 1H NMR spectra, absorption spectra, and their gel permeation chromatography (GPC) retention time. Furthermore, the structures of the dodecameric porphyrin squares ( 4 )4 and ( 5 )4 were probed by small‐ and wide‐angle X‐ray scattering (SAXS/WAXS) measurements in solution using a synchrotron source. Excitation‐energy migration processes in these assemblies were also investigated in detail by using both steady‐state and time‐resolved spectroscopic methods, which revealed efficient excited‐energy transfer (EET) between the meso–meso‐linked ZnII–porphyrin units that occurred with time constants of 1.5 ps?1 for ( 3 )2 and 8.8 ps?1 for ( 5 )4. 相似文献
15.
Dr. Min‐Xia Yao Qi Zheng Kang Qian Prof. Dr. You Song Prof. Dr. Song Gao Prof. Dr. Jing‐Lin Zuo 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(1):294-303
By using the node‐and‐spacer approach in suitable solvents, four new heterotrimetallic 1D chain‐like compounds (that is, containing 3d–3d′–4f metal ions), {[Ni(L)Ln(NO3)2(H2O)Fe(Tp*)(CN)3] ? 2 CH3CN ? CH3OH}n (H2L=N,N′‐bis(3‐methoxysalicylidene)‐1,3‐diaminopropane, Tp*=hydridotris(3,5‐dimethylpyrazol‐1‐yl)borate; Ln=Gd ( 1 ), Dy ( 2 ), Tb ( 3 ), Nd ( 4 )), have been synthesized and structurally characterized. All of these compounds are made up of a neutral cyanide‐ and phenolate‐bridged heterotrimetallic chain, with a {? Fe? C?N? Ni(? O? Ln)? N?C? }n repeat unit. Within these chains, each [(Tp*)Fe(CN)3]? entity binds to the NiII ion of the [Ni(L)Ln(NO3)2(H2O)]+ motif through two of its three cyanide groups in a cis mode, whereas each [Ni(L)Ln(NO3)2(H2O)]+ unit is linked to two [(Tp*)Fe(CN)3]? ions through the NiII ion in a trans mode. In the [Ni(L)Ln(NO3)2(H2O)]+ unit, the NiII and LnIII ions are bridged to one other through two phenolic oxygen atoms of the ligand (L). Compounds 1 – 4 are rare examples of 1D cyanide‐ and phenolate‐bridged 3d–3d′–4f helical chain compounds. As expected, strong ferromagnetic interactions are observed between neighboring FeIII and NiII ions through a cyanide bridge and between neighboring NiII and LnIII (except for NdIII) ions through two phenolate bridges. Further magnetic studies show that all of these compounds exhibit single‐chain magnetic behavior. Compound 2 exhibits the highest effective energy barrier (58.2 K) for the reversal of magnetization in 3d/4d/5d–4f heterotrimetallic single‐chain magnets. 相似文献
16.
Kai‐Long Zhong Li Chen Lin Chen 《Acta Crystallographica. Section C, Structural Chemistry》2011,67(2):m62-m64
The title compound, [Cu2(SO4)2(C10H8N2)2(C2H6O2)2(H2O)2]n, contains two crystallographically unique CuII centres, each lying on a twofold axis and having a slightly distorted octahedral environment. One CuII centre is coordinated by two bridging 4,4′‐bipyridine (4,4′‐bipy) ligands, two sulfate anions and two aqua ligands. The second is surrounded by two 4,4′‐bipy N atoms and four O atoms, two from bridging sulfate anions and two from ethane‐1,2‐diol ligands. The sulfate anion bridges adjacent CuII centres, leading to the formation of linear ...Cu1–Cu2–Cu1–Cu2... chains. Adjacent chains are further bridged by 4,4′‐bipy ligands, which are also located on the twofold axis, resulting in a two‐dimensional layered polymer. In the crystal structure, extensive O—H...O hydrogen‐bonding interactions between water molecules, ethane‐1,2‐diol molecules and sulfate anions lead to the formation of a three‐dimensional supramolecular network structure. 相似文献
17.
Influence of the Homopolar Dihydrogen Bonding CH⋅⋅⋅HC on Coordination Geometry: Experimental and Theoretical Studies 下载免费PDF全文
Dr. Damir A. Safin Dr. Maria G. Babashkina Dr. Koen Robeyns Dr. Mariusz P. Mitoraj Dr. Piotr Kubisiak Prof. Yann Garcia 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(46):16679-16687
The reaction of the N‐thiophosphorylated thiourea (HOCH2)(Me)2CNHC(S)NHP(S)(OiPr)2 (HL), deprotonated by the thiophosphorylamide group, with NiCl2 leads to green needles of the pseudotetrahedral complex [Ni(L‐1,5‐S,S′)2] ? 0.5 (n‐C6H14) or pale green blocks of the trans square‐planar complex trans‐[Ni(L‐1,5‐S,S′)2]. The former complex is stabilized by homopolar dihydrogen C?H???H?C interactions formed by n‐hexane solvent molecules with the [Ni(L‐1,5‐S,S′)2] unit. Furthermore, the dispersion‐dominated C?H??? H?C interactions are, together with other noncovalent interactions (C?H???N, C?H???Ni, C?H???S), responsible for pseudotetrahedral coordination around the NiII center in [Ni(L ‐1,5‐S,S′)2] ? 0.5 (n‐C6H14). 相似文献
18.
Broad Hexagonal Columnar Mesophases Formation in Bioinspired Transition‐Metal Complexes of Simple Fatty Acid meta‐Octaester Derivatives of meso‐Tetraphenyl Porphyrins 下载免费PDF全文
Dr. Bin Wu Keyang Chen Yuchen Deng Jian Chen Dr. Chengjie Liu Prof. Rongshi Cheng Prof.Dr. Dongzhong Chen 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(9):3671-3681
A series of meta‐substituted fatty acid octaester derivatives and their transition‐metal complexes of meso‐ tetraphenyl porphyrins (TPP‐8OOCR, with R=Cn?1H2n?1, n=8, 12, or 16) have been prepared through very simple synthesis protocols. The thermotropic phase behavior and the liquid crystalline (LC) organization structures of the synthesized porphyrin derivatives were systematically investigated by a combination of differential scanning calorimetry (DSC), polarized optical microscopy (POM), and variable‐temperature small‐angle X‐ray scattering/wide‐angle X‐ray scattering (SAXS/WAXS) techniques. The shorter octanoic acid ester substituted porphyrin (C8‐TPP) did not show liquid crystallinity and its metal porphyrins exhibited an uncommon columnar mesophase. The lauric acid octaester (C12‐TPP) and the palmitic acid octaester (C16‐TPP) series porphyrins generated hexagonal columnar mesophase Colh. Moreover, the metal porphyrins C12‐TPPM and C16‐TPPM with M=Zn, Cu, or Ni, exhibited well‐organized Colh mesophases of broad LC temperature ranges increasing in the order of TPPNi<TPPCu≤TPPZn with their increased effective ionic radii in the square‐planar coordination. The simplicity in synthesis, the well intercolumnar organization of Colh mesophase, the broadness of the discotic LC range, and the specific UV/Vis absorption and fluorescence emission behaviors make the symmetrically substituted fatty acid octaester porphyrins and their metal complexes very attractive for variant applications. 相似文献
19.
《Chemistry (Weinheim an der Bergstrasse, Germany)》2003,9(13):3055-3064
Structural and spectroscopic properties of and theoretical investigations on dinuclear [Pd2(CN)4(P–P)2] (P–P=bis(dicyclohexylphosphanyl)methane ( 1 ), bis(dimethylphosphanyl)methane ( 2 )) and mononuclear trans‐[Pd(CN)2(PCy3)2] ( 3 ) complexes are described. Xray structural analyses reveal Pd???Pd distances of 3.0432(7) and 3.307(4) Å in 1 and 2 , respectively. The absorption bands at λ>270 nm in 1 and 2 have 4d →5pσ electronic‐transition character. Calculations at the CIS level indicate that the two low‐lying dipole‐allowed electronic transition bands in model complex [Pd2(CN)4(μ‐H2PCH2PH2)2] at 303 and 289 nm are due to combinations of many orbital transitions. The calculated interaction‐energy curve for the skewed dimer [{trans‐[Pd(CN)2(PH3)2]}2] is attractive at the MP2 level and implies the existence of a weak PdII–PdII interaction. 相似文献
20.
A Benzene‐1,3,5‐Triaminyl Radical Fused with ZnII‐Porphyrins: Remarkable Stability and a High‐Spin Quartet Ground State 下载免费PDF全文
Daiki Shimizu Prof. Dr. Atsuhiro Osuka 《Angewandte Chemie (International ed. in English)》2018,57(14):3733-3736
A benzene‐1,3,5‐triaminyl radical fused with three ZnII‐porphyrins was synthesized through a three‐fold oxidative fusion reaction of 1,3,5‐tris(ZnII‐porphyrinylamino)benzene followed by oxidation with PbO2 as key steps. This triaminyl radical has been shown to possess a quartet ground state with a doublet–quartet energy gap of 3.1 kJ mol?1 by superconducting quantum interference device (SQUID) studies. Despite its high‐spin nature, this triradical is remarkably stable, which allows its separation and recrystallization under ambient conditions. Moreover, this triradical can be stored as a solid for more than one year without serious deterioration. The high stability of the triradical is attributed to effective spin delocalization over the porphyrin segments and steric protection at the nitrogen centers and the porphyrin meso positions. 相似文献