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1.
An Expanded Porphycene with High NIR Absorptivity That Stabilizes Two Different Kinds of Metal Complexes
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Dr. Gonzalo Anguera Dr. Won‐Young Cha Matthew D. Moore James T. Brewster II Michael Y. Zhao Dr. Vincent D. Lynch Prof. Dongho Kim Prof. Jonathan L. Sessler 《Angewandte Chemie (International ed. in English)》2018,57(10):2575-2579
A new expanded porphycene with 26 π‐electrons has been prepared by the McMurry coupling of 1,4‐bis(3,4‐diethyl‐2‐pyrryl)benzene dialdehyde. Expansion of the porphycene framework provides a ligand capable of stabilizing a bis(rhodium) and a monoruthenium complex. These new porphycene derivatives absorb strongly in the NIR spectral region, with appreciable absorptivity up to 1300 nm. On the basis of their ground‐ and excited‐state spectroscopic features and structural parameters, both the free‐base system and the bis(rhodium) complex are considered to be Hückel‐type aromatic systems. This conclusion is supported by DFT calculations. 相似文献
2.
meso‐Dibenzoporphycene has a Large Bathochromic Shift and a Porphycene Framework with an Unusual cis Tautomeric Form
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Dr. Koji Oohora Ayumu Ogawa Tamaki Fukuda Dr. Akira Onoda Prof. Dr. Jun‐ya Hasegawa Prof. Dr. Takashi Hayashi 《Angewandte Chemie (International ed. in English)》2015,54(21):6227-6230
meso‐Monobenzoporphycene (mMBPc) and meso‐dibenzoporphycene (mDBPc), in which one or two benzene moieties are fused at ethylene‐bridged positions (meso‐positions) of porphycene, were prepared in an effort to further delocalize the π‐electrons within the porphycene molecule. mMBPc and mDBPc were fully characterized by mass spectrometry, 1H and 13C NMR spectroscopy, and X‐ray crystallography. The longest‐wavelength Q‐bands of mMBPc and mDBPc are red‐shifted by 92 nm and 418 nm, respectively, compared to that of the unsubstituted porphycene (Pc). Electrochemical measurements indicate that the HOMO is destabilized and the LUMO is stabilized by the fused benzene moieties at the meso positions. Furthermore, both XPS and theoretical studies support the presence of a cis tautomeric form in the ground state of mDBPc, despite the fact that essentially all known porphycene derivatives adopt the trans tautomeric form. 相似文献
3.
Sperm whale myoglobin, an oxygen-storage hemoprotein, was reconstituted with 2,7-diethyl-3,6,12,17-tetramethyl-13,16-bis(carboxyethyl)porphycenatocobalt(II) in order to investigate the reactivities of a cobalt porphycene in a protein matrix. Similar to the previously reported finding for the myoglobin with the iron porphycene, the reconstituted myoglobin with the cobalt porphycene was also found to have an O2 affinity 2 orders of magnitude greater than that of the myoglobin possessing cobalt protoporphyrin IX. The EPR spectra of the deoxy and oxy myoglobins having the cobalt porphycene at 77 K also have features similar to those of the myoglobin with cobalt protoporphyrin IX. These spectra suggest that the porphycene cobalt in the deoxy form is coordinated by one nitrogenous ligand postulated to be the imidazole ring of His93, and that the bond configuration of CoII-O2 is regarded as the CoIII-Omicron2*- species. 相似文献
4.
Hayashi T Nakashima Y Ito K Ikegami T Aritome I Suzuki A Hisaeda Y 《Organic letters》2003,5(16):2845-2848
[structure: see text] A pyrrolic macrocycle, beta-tetrakis(trifluoromethyl)porphycene, is the first example of a fluorine-containing porphycene. Four electron-withdrawing CF(3) substituents provide a highly distorted structure and an attractive electron-deficient nature for the porphycene framework. From the electrochemical study, it is found that the LUMO energy level for the beta-trifluoromethylporphycene is 1.24 V more stabilized compared to that for etioporphyrin. Moreover, the deprotonation of the inner N[bond]H proton in the porphycene was observed upon the addition of DBU. 相似文献
5.
Naphthobipyrrole-derived porphycenes are synthesized for the first time via McMurry coupling of the β-alkylated 2,9-diformylnaphthobipyrrole derivatives, which in turn were prepared easily from 2,3-naphthalene bishydrazine in four steps. Insertion of nickel into the porphycene core results in transformation of the rectangular N4-core into a square type geometry owing to the fusion of naphthalene moiety onto the bipyrrole entities. These porphycenes show large, intensity dependent three-photon absorption. 相似文献
6.
Shimakoshi H Baba T Iseki Y Aritome I Endo A Adachi C Hisaeda Y 《Chemical communications (Cambridge, England)》2008,(25):2882-2884
A heavy atom, bromine, was directly substituted into the porphycene macrocycle to promote intersystem crossing by way of spin-orbit coupling. The singlet oxygen production ability of the porphycene is dramatically enhanced, and the highest value of 0.95 for the quantum yield of singlet oxygen generation (PhiDelta) was obtained for the dibrominated porphycene by visible light excitation. 相似文献
7.
Gawinkowski S Walewski Ł Vdovin A Slenczka A Rols S Johnson MR Lesyng B Waluk J 《Physical chemistry chemical physics : PCCP》2012,14(16):5489-5503
Combined use of IR, Raman, neutron scattering and fluorescence measurements for porphycene isolated in helium nanodroplets, supersonic jet and cryogenic matrices, as well as for solid and liquid solutions, resulted in the assignments of almost all of 108 fundamental vibrations. The puzzling feature of porphycene is the apparent lack of the N-H stretching band in the IR spectrum, predicted to be the strongest of all bands by standard harmonic calculations. Theoretical modeling of the IR spectra, based on ab initio molecular dynamics simulations, reveals that the N-H stretching mode should appear as an extremely broad band in the 2250-3000 cm(-1) region. Coupling of the N-H stretching vibration to other modes is discussed in the context of multidimensional character of intramolecular double hydrogen transfer in porphycene. The analysis can be generalized to other strongly hydrogen-bonded systems. 相似文献
8.
Stepień M Donnio B Sessler JL 《Chemistry (Weinheim an der Bergstrasse, Germany)》2007,13(24):6853-6863
A number of substituted zinc(II) porphycenes and porphyrins have been synthesized as potentially mesogenic materials. One of the resulting porphycenes, bearing eight decyloxy chains, exhibits two mesophases, a transient lamellar phase (Lam) and a highly ordered lamello-columnar phase (L(Col)), with remarkably different structural characteristics. The same zinc(II) porphycene also forms an electron donor-acceptor (EDA) complex with tetracyanoquinodimethane (TCNQ), generating a hexagonal columnar mesophase (Col(h)) that is thermally stable up to ca. 200 degrees C. The EDA interaction between porphycene and TCNQ has been probed using electronic and vibrational spectroscopy. A mixture of zinc(II) porphyrins, isomeric with the above porphycene complex, forms a rectangular columnar mesophase (Col(r)). 相似文献
9.
A procedure that enables determining the reaction rate from the analysis of fluorescence anisotropy is described and applied to the investigation of double hydrogen transfer between inner-cavity nitrogen atoms in electronically excited porphycene. Tautomerization proceeds as a thermally activated synchronous double hydrogen tunneling. The barrier to the reaction is dynamically modulated by a vibration that simultaneously changes the strength of two intramolecular hydrogen bonds. Different mechanisms of tautomerization in porphycene and its parent isomer, porphyrin, can be understood by analyzing the potentials for hydrogen transfer. 相似文献
10.
Kim KS Sung YM Matsuo T Hayashi T Kim D 《Chemistry (Weinheim an der Bergstrasse, Germany)》2011,17(28):7882-7889
In this study, we have investigated the relationship between aromaticity and photophysical properties of trifluoromethyl-substituted [18]/[20]π porphycenes by using theoretical calculations and various spectroscopic methodologies. Interestingly, we have found that the HOMO-LUMO gap of [20]π porphycene is larger than that of [18]π porphycene, which is in a sharp contrast with those of typical [4n]/[4n+2]π porphyrinoids. Based on our observations, we demonstrate that the origin of this contrasting feature of [20]π porphycene arises from the uniquely large energy splitting between LUMO and LUMO+1 of [18]π porphycene compared with other aromatic [4n+2]π porphyrinoids with nearly degenerate LUMO/LUMO+1. Consequently, we can propose that the energy difference between LUMO and LUMO+1 levels of aromatic [4n+2]π porphyrinoids is an important factor in determining the electronic nature of their corresponding antiaromatic [4n]π porphyrinoids. Moreover, to the best of our knowledge, this is the first study to illustrate the photophysical properties of porphycenes with [4n]π electronic circuits. 相似文献
11.
Ning Xu Dr. Toshikazu Ono Prof. Yoshio Hisaeda 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(50):11680-11687
The main obstacle to the widespread application of porphycenes lies in the lack of efficient and economical methods for their production. Discovery of new synthetic methodologies for porphycene derivatives are important for fine-tuning of their optical and electrochemical properties. Herein, the preparation of a set of AABB-, ABAB-, and ABBA-type meso-tetrasubstituted unsymmetric porphycenes is reported. Their synthesis involved the acid-catalyzed oxidative coupling of AA- and BB-dipyrroethenes, or AB-type dipyrroethenes, as precursors in yields of up to 19 %. The structures were unambiguously confirmed by X-ray crystallography. The type and position of substituents in the unsymmetric porphycenes enabled fine-tuning of the optical and electronic properties, which are discussed in terms of their UV/Vis absorption, fluorescence spectroscopies, cyclic voltammetry, and density functional theory calculations. 相似文献
12.
Takehiro YoshikawaShuichi Sugawara Toshiyuki Takayanagi Motoyuki ShigaMasanori Tachikawa 《Chemical physics》2012,394(1):46-51
Path-integral molecular dynamics simulations have been performed for porphycene and its isotopic variants in order to understand the effect of isotopic substitution of inner protons on the double proton transfer mechanism. We have used an on-the-fly direct dynamics technique at the semiempirical PM6 level combined with specific reaction parameterization. Our quantum simulations show that double proton transfer of the unsubstituted porphycene at T = 300 K mainly occurs via a so-called concerted mechanism through the D2h second-order saddle point. In addition, we found that both isotopic substitution and temperature significantly affect the double proton transfer mechanism. For example, the contribution of the stepwise mechanism increases with a temperature increase. We have also carried out hypothetical simulations with the porphycene configurations being completely planar. It has been found that out-of-plane vibrational motions significantly decrease the contribution of the concerted proton transfer mechanism. 相似文献
13.
Pietrzak M Shibl MF Bröring M Kühn O Limbach HH 《Journal of the American Chemical Society》2007,129(2):296-304
The 1H and 2H NMR spectra of porphycene (1), 2,3,6,7,12,13,16,17-octaethylporphycene (2), 2,7,12,17-tetra-n-propylporphycene (3), and 2,7,12,17-tetra-(tert-butyl)-3,6-13,16-dibenzo[cde;mno]porphycene (4) partially deuterated in the mobile proton sites are reported. These compounds exhibit two intramolecular NHN hydrogen bonds of increasing strength representing models of the concerted HH transfer in the parent compound, porphycene. The 1H chemical shifts of the mobile protons are correlated with the difference of the energies of the amino- and imino-N1s orbitals reported by Ghosh A.; Moulder J.; Br?ring M.; Vogel E. Angew. Chem., Int. Ed. 2001, 113, 445-448. The chemical shifts of 4 indicate a reduced contribution of the aromatic ring current as compared to the other compounds which is associated to the nonplanarity of this molecule. The primary H/D isotope effects on the chemical shifts give information about the primary, secondary, and vicinal geometric isotope effects of the two inner hydrogen bonds of porphycenes. The vicinal effects indicate a cooperative coupling of the two hydrogen bonds which may favor a concerted double proton-transfer mechanism. 相似文献
14.
In the context of naturally occurring nitrogen heterocycles, nicotine is a chiral alkaloid present in tobacco plants, which can target and stimulate nicotinic acetylcholine receptors (nAChRs), a class of ligand-gated ion channels commonly located throughout the human brain. Due to its well-known toxicity for humans, there is considerable interest in the development of synthetic analogues; in particular, conformationally restricted analogues of nicotine have emerged as promising drug molecules for selective nAChR-targeting ligands. In the present mini-review, we will describe the synthesis of the conformationally restricted analogues of nicotine involving one or more catalytic processes. In particular, we will follow a systematic approach as a function of the heteroarene structure, considering: (a) 2,3-annulated tricyclic derivatives; (b) 3,4-annulated tricyclic derivatives; (c) tetracyclic derivatives; and (d) other polycyclic derivatives. For each of them we will also consider, when carried out, biological studies on their activity for specific nAChR subunits. 相似文献
15.
Jakub Ostapko Dr. Krzysztof Nawara Michał Kijak Dr. Joanna Buczyńska Dr. Barbara Leśniewska Dr. Mariusz Pietrzak Grażyna Orzanowska Prof. Jacek Waluk 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(48):17311-17320
Among seven possible nitrogen‐in constitutional isomers of porphyrin only one, porphycene, has been obtained so far in the free, unsubstituted form. Herein, the synthesis of another isomer, parent hemiporphycene ( HPc ), and its thorough structural, spectral, photophysical, electrochemical, and theoretical characterization are reported. Most of the properties of HPc are intermediate between those of porphyrin and porphycene, as evidenced by the values of inner‐cavity dimensions, orbital‐energy splittings, absorption coefficients, magnetic circular dichroism parameters, NH‐stretching frequencies, fluorescence quantum yields, tautomerization rates, and redox potentials. The largest differences arise with respect to tautomerism, due to the low symmetry of HPc and inequivalence of the four nitrogen atoms that define the inner cavity. Two trans tautomers are observed, separated in energy by about 1 kcal mol?1. Tautomerization from the higher‐ to the lower‐energy form is detected in the lowest‐excited singlet state and occurs at a rate that is about four orders of magnitude lower than that observed for porphycene. Hemiporphycene is a very good model for the investigation of inequivalent intramolecular H‐bonds present in one molecule; two such bonds in HPc reveal unusual characteristics, and the bond strength results from the interplay between the N ??? N distance and the N?H?N angle. 相似文献
16.
Weigand JJ Riegel SD Burford N Decken A 《Journal of the American Chemical Society》2007,129(25):7969-7976
Versatile alkylation reactions give access to symmetric, homoleptic nonsymmetric, and heteroleptic symmetric hexaalkylated 1,2-diphosphonium derivatives as bottleable salts in high yields. A series of 1,2-diphosphonium salts has been isolated and characterized, representing prototypical phosphorus analogues of ethane. Additionally, the solid-state structures for four derivatives have been determined crystallographically. Nonsymmetrically substituted derivatives of 1,2-diphosphonium cations enable the direct observation of 1J(PAPB) coupling constants for two tetracoordinate phosphorus centers. The synthetic approaches promise access to a vast array of derivatives and will provide means to the systematic development of phosphorus analogues of hydrocarbon chemistry. 相似文献
17.
Gawinkowski S Orzanowska G Izdebska K Senge MO Waluk J 《Chemistry (Weinheim an der Bergstrasse, Germany)》2011,17(36):10039-10049
2,3,7,8,12,13,17,18‐Octaethyl‐5,15‐diphenylporphyrin ( 1 ) is characterized by an inner cavity with a rectangular shape and small NH???N distances. It resembles porphycene, which is a constitutional isomer of porphyrin known for its strong intramolecular hydrogen bonds and rapid tautomerization. Such distortion of the porphyrin cavity leads to tautomeric properties of 1 that are intermediate between those of porphyrin and porphycene. In particular, a tautomerization in the lowest excited singlet state of 1 has been discovered, occurring with a rate three orders of magnitude lower than that in porphycene, but three to four orders of magnitude higher than that in porphyrin. An isomer of 1 , 2,3,7,8,12,13,17,18‐octaethyl‐5,10‐diphenylporphyrin ( 2 ), exhibits a different kind of geometry distortion. This molecule is nonplanar, but the inner cavity shape and dimensions are similar to those of the parent porphyrin. The same hydrogen‐bonding strength as that in porphyrin is observed for 2 . In contrast, the nonplanarity of 2 significantly influences the photophysics, leading to a decrease in fluorescence quantum yield and lifetime. Absorption, magnetic circular dichroism, and fluorescence spectra are similar for 1 and 2 and resemble those of parent porphyrin. This is a consequence of comparable energy splittings of the frontier orbitals, ΔHOMO≈ΔLUMO. The results demonstrate that judicious selection of substituents and their position enables a controlled modification of geometry, hydrogen‐bonding strength, tautomerization rate, and photophysical and spectral parameters of porphyrinoids. 相似文献
18.
Determination of the rotational diffusion tensor of porphycene by 13C and 1H spin relaxation methods
Bernatowicz P 《The journal of physical chemistry. A》2011,115(31):8604-8607
The longitudinal (13)C and (1)H relaxation rates were determined in porphycene in CD(2)Cl(2) solution. These data, augmented by (13)C{(1)H} NOE enhancements were numerically analyzed to evaluate the rotational diffusion tensor of the molecule and the vibrational correction for the one-bond (13)C-(1)H dipolar couplings. The (13)C and (1)H relaxation data seem to be consistent with each other, and the emerging picture of the rotational dynamics of porphycene compares well with the results that can be found in the literature. 相似文献
19.
Hisashi Shimakoshi Yusuke Iseki Chihaya Adachi Yoshio Hisaeda 《Tetrahedron letters》2008,49(43):6198-6201
Porphycene was covalently immobilized in a sol-gel silica film deposited on a glass plate, and the immobilized porphycene showed a photosensitizing property with recycling for the photo-oxidation of 1,5-dihydroxynaphthalene. 相似文献
20.
Weist S Kittel C Bischoff D Bister B Pfeifer V Nicholson GJ Wohlleben W Süssmuth RD 《Journal of the American Chemical Society》2004,126(19):5942-5943
In the mutasynthetic approach, the DeltadpgA mutant of the vancomycin-type glycopeptide antibiotic producer Amycolatopsis balhimycina, which is deficient in the synthesis of 3,5-dihydroxyphenylglycine (DPg), was supplemented with synthetic DPg analogues to obtain the corresponding modified glycopeptides. Sterically more demanding 3,5-disubstituted methoxy derivatives as well as monosubstituted DPg analogues were accepted as substrates. These facts indicate that steric and electronic requirements suffice in several cases for the oxidative closure of the AB ring, thus leading to the generation of novel antibiotically active glycopeptide derivatives. The results represent a further step in evaluating the potential of mutasynthesis for peptidic secondary metabolites. 相似文献