18750-95-3Relevant articles and documents
Molecular Turnstiles Regulated by Metal Ions
Wang, Guangxia,Xiao, Hongmei,He, Jiaojiao,Xiang, Junfeng,Wang, Ying,Chen, Xuebo,Che, Yanke,Jiang, Hua
, p. 3364 - 3371 (2016)
A family of novel molecular turnstiles 1-3 composed of two stators with pyridyl binding sites and a different-sized triptycene rotor was synthesized. The molecular turnstiles behave in an open state at room temperature in the absence of metal ions but display significantly different closed states in the presence of Ag+ and Pd2+. The Ag+-mediated turnstiles 1-3Ag exhibited closed states but unreadable bistability at ambient temperature because the Ag+-mediated macrocyclic framework is not able to restrict the rotations of the rotors; while temperature was decreased, the macrocyclic frameworks became stable enough to halt the rotations of the rotors, eventually leading to the readable closed states for 1-3Ag. In contrast, Pd2+-mediated macrocyclic frameworks are stable, giving rise to a detectable closed state of turnstiles 1-3Pd in a wide range of temperatures. These findings have also been supported by DFT calculations.
Zinc-Ion-Stabilized Charge-Transfer Interactions Drive Self-Complementary or Complementary Molecular Recognition
Iseki, Shuta,Kishida, Sakura,Nonomura, Kohei,Ogata, Daiji,Yuasa, Junpei
, p. 15842 - 15851 (2020)
Here, we show that charge-transfer interactions determine whether donor and acceptor ditopic ligands will associate in a complementary or self-complementary fashion upon metal-ion clipping. Anthracene-based (9,10LD and 1,5LD) and anthraquinone-based (1,5LA) ditopic ligands containing two imidazole side arms as zinc coordination sites were designed. The 9,10LD and 1,5LA systems associated in a complementary fashion (LA/LD/LA) upon clipping by two zinc ions (Zn2+) to form an alternating donor-acceptor assembly [(9,10LD)(1,5LA)2-(Zn2+)2]. However, once the charge-transfer interactions were perturbed by subtle modifications of the imidazole side arms (9,10LD′(S) and 1,5LA′(S)), self-complementary association (LD′/LD′/LD′/LD′ and LA′/LA′/LA′/LA′) between the donor (9,10LD′(S)) and acceptor (1,5LA′(S)) ligands predominantly occurred to form homoassemblies [(9,10LD′(S))4-(Zn2+)2 and (1,5LA′(S))4-(Zn2+)2]. As in the case of a homochiral pair (9,10LD′(S) and 1,5LA′(S)), self-complementary association (narcissistic self-sorting) occurred in the Zn2+ assembly with heterochiral combinations of the donor and acceptor ligands (9,10LD′(S)/1,5LA′(R) and 9,10LD′(S)/1,5LA′(R)/1,5LA′(R)). Narcissistic self-sorting also took place between the positional isomer of the donor ligands (9,10LD and 1,5LD) to form individual homoligand assemblies [(9,10LD)4-(Zn2+)2 and (1,5LD)4-(Zn2+)2]. Conversely, statistical association took place in the Zn2L4 assembly process of an isomorphous pair of the donor and acceptor ligands (1,5LD and 1,5LA).
Self-assembled trigonal prismatic altitudinal rotors with triptycene paddle wheels
Caskey, Douglas C.,Wang, Bing,Zheng, Xiaolai,Michl, Josef
, p. 1970 - 1985 (2005)
We describe the synthesis of a trigonal prismatic molecular rotor by self-assembly from paddle-wheel carrying molecular rods and trigonal star connectors in a 3:2 ratio. The rod is 9,10-diethynyltriptycene terminated in transversely reactive [Pt(dppp)]+ groups (dppp = 1,3- bis(diphenylphosphino)propane) and the connector is 1,3,5-tris[(4-pyridyl) ethynyl]benzene. The structure of the molecular rotor has been established by 2-D NMR and MS, including diffusion-ordered NMR and collision-induced dissociation.
Competing Allosteric Mechanisms for Coordination-Directed Conformational Changes of Chiral Stacking Structures with Aromatic Rings
Nonomura, Kohei,Yuasa, Junpei
, p. 6474 - 6484 (2019)
This work revealed that significant asymmetric nonlinear effects can be found in a coordination-directed conformational alteration through competing allosteric mechanisms. Toward this aim, we have prepared new chiral bridging ligands [(S,S)- and (R,R)-Im2An] containing an anthracene ring as a spacer with two ethynyl-linked chiral imidazole groups at the 9,10-positions. The (S,S)- and (R,R)-Im2An ligands (L) spontaneously form the assemblies with Zn2+ ions (M) in solution phase, giving L4M2-type assemblies with a general formula [(S,S)- or (R,R)-Im2An]4(Zn2+)2. NMR studies revealed that the [(S,S)-Im2An]4(Zn2+)2 assembly has an anthracene dimer structure with a parallel-displaced geometry, leading to relatively small circular dichroism (CD) signals, as expected for nonchiral objects. Conversely, subsequent addition of chiral coligands [(R)- or (S)-Ph-box] to [(S,S)-Im2An]4(Zn2+)2 afforded an alternative Zn2+ assembly with general formula [(R)- or (S)-Ph-box]2[(S,S)-Im2An]2(Zn2+)2, where the chiral coligands expel two of the (S,S)-Im2An ligands that were singly bound to the Zn2+ ions in the original [(S,S)-Im2An]4(Zn2+)2 assembly. This ligand-exchange reaction causes conformational alteration from a parallel-displaced structure to a twisted stacking between the anthracene rings inside the Zn2+ assembly, which results in a significant enhancement of CD signals due to excitonic interactions of the chiral anthracene dimer. Dissymmetry factor (gCD) for CD due to chiral stacking structures shows a significant inverse sigmoidal response to the enantiomeric excess of the chiral coligands. The observed nonlinear phenomena are results of the two conflicting mechanisms, homochiral cooperative association (homochiral self-sorting) to form CD-active assemblies [(S)- or (R)-Ph-box]2[(S,S)-Im2An]2(Zn2+)2 versus heterochiral cooperative dissociation of [(S,S)-Im2An]4(Zn2+)2 by sequestering of Zn2+ inside the assembly through formation of a heterochiral 2:1 Zn2+ complex ([(R)-Ph-box][(S)-Ph-box]Zn2+). The presented mechanisms provide a new strategy for generating switch-like OFF/ON states in chiral systems.
The relationship between molecular structure and electronic properties in dicyanovinyl substituted acceptor-donor-acceptor chromophores
Tarku?, Simge,Eelkema, Rienk,Grozema, Ferdinand C.
, p. 4994 - 5004 (2017/07/27)
In this contribution we describe a combined experimental and theoretical study of the relation between the molecular structure and the electronic properties of conjugated donor-acceptor type chromophores for light-harvesting applications. A series of model systems was synthesized where a central anthracene (electron donor) is connected to dicyanovinyl units (electron acceptor) through a π-conjugated spacer. The study of the redox and optical properties of these chromophores and of reference compounds without dicyanovinyl units allows us correlate the electronic properties to the presence of the electron withdrawing groups and the molecular conformation. Comparison with calculated electronic structure shows that the construction of chromophores that consist of electron donating and accepting units does not always follow the simple rules that are generally used in the design of such molecules. The results show a subtle relation between the charge transfer character and the geometry of the molecules. In some cases this leads to significant contribution of charge transfer excitation to the absorption spectra of some chromophores while such contributions are completely absent in others.
Intermolecular On-Surface σ-Bond Metathesis
Gao, Hong-Ying,Held, Philipp Alexander,Amirjalayer, Saeed,Liu, Lacheng,Timmer, Alexander,Schirmer, Birgitta,Díaz Arado, Oscar,M?nig, Harry,Mück-Lichtenfeld, Christian,Neugebauer, Johannes,Studer, Armido,Fuchs, Harald
supporting information, p. 7012 - 7019 (2017/05/31)
Silylation and desilylation are important functional group manipulations in solution-phase organic chemistry that are heavily used to protect/deprotect different functionalities. Herein, we disclose the first examples of the σ-bond metathesis of silylated alkynes with aromatic carboxylic acids on the Ag(111) and Au(111) surfaces to give the corresponding terminal alkynes and silyl esters, which is supported by density functional theory calculations and further confirmed by X-ray photoelectron spectroscopy analysis. Such a protecting group strategy applied to on-surface chemistry allows self-assembly structures to be generated from molecules that are inherently unstable in solution and in the solid state. This is shown by the successful formation of self-assembled hexaethynylbenzene at Ag(111). Furthermore, it is also shown that on the Au(111) surface this σ-bond metathesis can be combined with Glaser coupling to fabricate covalent polymers via a cascade process.
Cascade energy transfer and tunable emission from nanosheet hybrids: Locating acceptor molecules through chiral doping
Goudappagouda,Wakchaure, Vivek Chandrakant,Ranjeesh, Kayaramkodath Chandran,Abhai, Chalona Antony Ralph,Babu, Sukumaran Santhosh
supporting information, p. 7072 - 7075 (2017/07/10)
Light harvesting donor-acceptor assemblies are indispensable to efficiently tap photons. In an attempt to improve the light harvesting efficiency of an acceptor doped assembly, we design and synthesize a donor-acceptor-donor triad which exhibits an except
Highly Luminescence Anthracene Derivatives as Promising Materials for OLED Applications
Slodek, Aneta,Filapek, Michal,Schab-Balcerzak, Ewa,Grucela, Marzena,Kotowicz, Sonia,Janeczek, Henryk,Smolarek, Karolina,Mackowski, Sebastian,Malecki, Jan Grzegorz,Jedrzejowska, Agnieszka,Szafraniec-Gorol, Grazyna,Chrobok, Anna,Marcol, Beata,Krompiec, Stanislaw,Matussek, Marek
, p. 4020 - 4031 (2016/08/24)
Novel symmetrical anthracene derivatives with bulky carbazolyl-fluorene, diphenylamino-fluorene, or carbazolyl-carbazole units connected to the anthracene frame through an ethynyl bridge were synthesized in excellent yield by using Sonogashira cross-coupling. The ethynyl bridge in the anthracene dyes increases π-electron conjugation and the bulky substituents considerably attenuate intermolecular interactions. The dyes possess high thermal stability, tremendous solubility in common organic solvents, and especially high photoluminescence quantum yield (Φf) in solution in the range of 77–98 %. OLED devices were fabricated. The AFM images of thin films and blends prepared from all compounds show a uniform and flat surface, indicating excellent film-forming properties. Devices incorporating the anthracene derivative with diphenylamino-fluorene end-capping groups exhibited the highest value of current density (J). All of the fabricated OLED devices emitted yellowish-orange light under applied voltage.
π-extended anthracenes as sensitive probes for mechanical stress
G?stl,Sijbesma
, p. 370 - 375 (2015/12/26)
Smart molecular systems having the ability to report on mechanical strain or failure in polymers via alteration of their optical properties are of great interest in materials science. However, only limited attention has been devoted to targeted chromophore engineering to fine-tune their physicochemical properties. Here, we describe the synthesis of π-extended anthracenes that can be released from their respective maleimide Diels-Alder adducts through the application of mechanical stress in solution and in the solid state. We demonstrate the improvement of fluorescence quantum yield as well as the tuning of excitation and emission wavelengths while retaining their excellent mechanochemical properties laying the foundation for a new series of mechanophores whose spectral characteristics can be modularly adjusted.
Anthracene derived dinuclear gold(I) diacetylide complexes: Synthesis, photophysical properties and supramolecular interactions
Mishra, Veenu,Raghuvanshi, Abhinav,Saini, Anoop Kumar,Mobin, Shaikh M.
, p. 103 - 109 (2016/05/02)
New anthracene derived dinuclear Au(I)-diacetylide complex (1) has been synthesized in which two Au(I) units are attached at 9,10- positions of ethynyl anthracene moiety. 1 exhibits rare non-covalent intermolecular Au?H-C interactions, leading to the formation of a supramolecular 2D-network. Further, to understand the effect of CCAuPPh3 units at different position, complexes (2) and (3) were synthesized, where CCAuPPh3 units are attached to 2,6- and 1,8- positions of anthracene, respectively. The absorption and emission spectra of 1-3 have been studied and surprisingly 1 was found to be highly fluorescent with high quantum yield compared to 2 and 3, this may be due to more perturbation of Au(I) on π system. Complexes 1-3 have been characterized by elemental analysis, NMR and Mass spectroscopy and authenticated by their single-crystal X-ray structures.
