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1,3-Dipyrrolyl-1,3-propanediones, synthesized from pyrroles and malonyl chloride, form BF2 complexes, which represent a new class of naked-eye sensors for halide and oxoanions. The association mode for the interactions of both the pyrrolyl NH and bridging CH protons with anions was confirmed by 1H NMR chemical shifts in CD2Cl2 and supported by theoretical studies. The binding constants (Ka) were estimated as 8.1x10(4), 2.0x10(3), 3.3x10(2), 1.3x10(4), and 80 M(-1) for F-, Cl-, Br-, H2PO4(-), and HSO4(-) by UV/Vis absorption spectral changes in CH2Cl2. Augmentation of Ka compared with dipyrrolylquinoxaline for H2PO4(-) is much larger than those for other anions. Contrary to other anions, F- quenches the emission almost completely, which was detected by the fluorescence spectrum as well as the naked-eye. In the case of the chloride anion complex, the formation of Cl(-)-bridged 1D networks, in which anion is associated with two BF2 complexes, is observed in the solid state. 相似文献
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One‐Handed Single Helicates of Dinickel(II) Benzenehexapyrrole‐α,ω‐diimine with an Amine Chiral Source 下载免费PDF全文
Dr. Chaolu Eerdun Satoshi Hisanaga Prof. Dr. Jun‐ichiro Setsune 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(1):239-246
Benzenehexapyrrole‐α,ω‐dialdehyde, composed of a pair of formyltripyrrole units with a 1,3‐phenylene linker, was metallated to give dinuclear single‐stranded helicates. X‐ray studies of the bis‐nickel(II) complex showed a helical C2 form with a pair of helical–metal coordination planes of a 3N+O donor set. The terminal aldehyde was readily converted into the imine by optically active amines, whereby helix‐sense bias was induced. Bis‐nickel(II) and bis‐palladium(II) complexes of the benzenehexapyrrole‐α,ω‐diimines were studied to show that an enantiomer pair of the helical C2 form are interchanged by slow flipping of each coordination plane and fast rotation around the C(benzene)?C(pyrrole) bond. The helical screw in the bis‐nickel(II) complexes was biased to one side in more than 95 % diastereoselectivity, which was achieved by using a variety of optically active amines, such as (R)‐1‐cyclohexylethylamine, (S)‐1‐ phenylethylamine, L ‐Phe(OEt) (Phe=phenylalanine), and (R)‐valinol. The nickel complexes showed much better diastereoselectivity than the corresponding palladium complexes. 相似文献
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Dr. Chaolu Eerdun Thi Hien Thuy Nguyen Takuya Okayama Satoshi Hisanaga Prof. Dr. Jun-ichiro Setsune 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(22):5777-5786
The hexapyrrole-α,ω-dicarbaldehydes 1 a and 1 b were metallated with CuII, NiII, and PdII to give bimetallic complexes where a pair of 3 N+O four-coordinate metal planes are helically distorted and the central 2,2′-bipyrrole subunit adopts a cis or trans conformation. X-ray crystallographic analysis of the bisCu complex revealed a closed form with a cis-2,2′-bipyrrole subunit and an open form with a trans-2,2′-bipyrrole subunit. The bisPd complexes took a closed form both in the solid state and in solution. They are regarded as single helicates of two turns and the energy barrier for the interchange between an M helix and a P helix was remarkably influenced by the bulky 3,3′-substituent of the central 2,2′-bipyrrole subunit. Although the bisNi complexes adopt a closed form in the solid state, they exist as a homohelical open C2-symmetric form or a heterohelical open Ci-symmetric form in solution. A theoretical study suggested that the closed form of 1 a Pd was stabilized by the Pd–Pd interaction. Compound 1 a Pd was reversibly oxidized by one electron at 0.14 V versus ferrocene/ferrocenium (Fc/Fc+) and this oxidized species showed Vis/NIR absorption bands at λ=767 and 1408 nm. 相似文献
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Summary The second order polarizabilities, xxx, of six linear oligopyrroles of the arylalkylidene-dipyrrinone type (the synthesis of two of them is reported) were estimated from their solvatochromic shifts. A dimethylaminophenylmethylene and a benzodithioleylidenemethylene derivative (2,6) were found to exhibit rather high xxx values.
Zur Chemie von Pyrrolpigmenten, 88. Mitt.: Nicht-lineare optische Eigenschaften von linearen Oligopyrrolen
Zusammenfassung Die Polarisierbarkeiten zweiter Ordnung, xxx, von sechs linearen Oligopyrrolen des Arylalkyliden-pyrrolinon-Typs (die Synthese zweier solcher Derivate wird mitgeteilt) wurden aus ihrem solvatochromen Verhalten abgeschätzt. Ein Dimethylaminophenylmethylen-und ein Benzodithiolylidenmethylen-Derivat (2,6) zeigen bemerkenswert hohe xxx-Werte.相似文献
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Ritika Gautam Dr. Jonathan J. Loughrey Dr. Andrei V. Astashkin Prof. Dr. Jason Shearer Prof. Dr. Elisa Tomat 《Angewandte Chemie (International ed. in English)》2015,54(49):14894-14897
The tripyrrin‐1,14‐dione scaffold of urinary pigment uroerythrin coordinates divalent palladium as a planar tridentate ligand. Spectroscopic, structural and computational investigations reveal that the tripyrrindione ligand binds as a dianionic radical, and the resulting complex is stable at room temperature. One‐electron oxidation and reduction reactions do not alter the planar coordination sphere of palladium(II) and lead to the isolation of two additional complexes presenting different redox states of the ligand framework. Unaffected by stability problems common to tripyrrolic fragments, the tripyrrindione ligand offers a robust platform for ligand‐based redox chemistry. 相似文献
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Yating Fu Xiujun Liu Chengjie Li Zhangfa Tong Glib Baryshnikov Hans gren Qizhao Li Yongshu Xie 《化学:亚洲杂志》2020,15(8):1285-1289
Oxidation of a thiophene‐hexapyrrane hybrid S‐P6 afforded a stable conjugated open‐chain thiaheptapyrrolic helix 1 with the terminal thiophene and confused pyrrole units lying at a long distance that is adverse for further cyclization. Chelation of 1 with copper(II) ion afforded 1‐Cu , which exhibits more distant terminal units. Interestingly, further oxidation of 1 triggered an intramolecular C?N fusion reaction to afford a unique 5,5,5‐tricyclic fused linear thiaheptapyrrin 2 , with the two terminals positioned in proximity, which favors the oxidative ring‐closure reaction to give a unique 5,5,5‐tricyclic fused thiaheptaphyrin (1.1.1.1.1.1.0) 3 under air. The inner‐fusion strategy for positioning the reactive sites in proximity to promote oxidative cyclization offers a new approach for constructing large porphyrinoids through conjugated oligopyrrins without the assistance of metal ions. 相似文献
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Oligopyrroles represent a diverse class of molecular receptors that have been utilized in a growing number of applications. Recently, these systems have attracted interest as receptors and chemosensors for hazardous materials, including harmful anionic species, high-valent actinide cations, and nitroaromatic explosives. These versatile molecular receptors have been used to develop rudimentary colorimetric and fluorimetric assays for hazardous materials. 相似文献
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