- [WS4Cu3I2]- and [WS 4Cu4]2+ secondary building units formed a metal-organic framework: Large tubes in a highly interpenetrated system
-
A 3D metal-organic framework, {[WS4Cu4(dpbp) 4]2+·[WS4Cu3(dpbp) 2I2]-·I-}n· xSolvent, [dpbp = 4,4′-di(4-pyridyl)biphenyl] with an unpr
- Lu, Zhen-Zhong,Zhang, Rui,Li, Yi-Zhi,Guo, Zi-Jian,Zheng, He-Gen
-
-
Read Online
- A Dynamic Tetracationic Macrocycle Exhibiting Photoswitchable Molecular Encapsulation
-
Designing macrocycles with appropriate molecular recognition features that allow for the integration of suitable external stimuli to control host-guest processes is a challenging endeavor which enables molecular containers to solubilize, stabilize, and separate chemical entities in an externally controllable manner. Herein, we introduce photo- and thermal-responsive elements into a semi-rigid tetracationic cyclophane, OPVEx2Box4+, that is composed of oligo(p-phenylenevinylene) pyridinium units and the biphenylene-bridged 4,4-bipyridinium extended viologens and adopts a rectangle-like geometry. It transpires that when the photoactive oligo(p-phenylenevinylene) pyridinium unit is incorporated in a macrocyclic scaffold, its reversibility is dramatically improved, and the configurations of the cyclophane can go back and forth between (EE)- and (EZ)-isomers upon alternating blue light irradiation and heating. When the macrocycle is found in its (EE)-configuration, it is capable of binding various π-electron-rich guests - e.g., anthracene and perylene - as well as π-electron-deficient guests - e.g., 9,10-anthraquinone and 5,12-tetracenequinone - through charge-transfer and van der Waals interactions. When irradiated with blue light, the (EE)-isomer of the cyclophane can be transformed successfully to the (EZ)-isomer, resulting in the switching off of the binding affinity for guest molecules, which are bound once again upon heating. The use of light and heat as external stimuli to control host-guest interactions involving a multi-responsive host and various guests provides us with a new opportunity to design and construct more-advanced molecular switches and machines.
- Wu, Huang,Chen, Yong,Zhang, Long,Anamimoghadam, Ommid,Shen, Dengke,Liu, Zhichang,Cai, Kang,Pezzato, Cristian,Stern, Charlotte L.,Liu, Yu,Stoddart, J. Fraser
-
supporting information
p. 1280 - 1289
(2019/01/14)
-
- Diverse Multi-Functionalized Oligoarenes and Heteroarenes for Porous Crystalline Materials
-
A modular synthesis of multi-functionalized biphenyl, terphenyl and higher linear oligophenylene dicarboxylic acids and pyridine-terminated oligoarenes by stepwise palladium–catalyzed borylation/Suzuki–Miyaura cross-coupling reactions is described. The presence of several distinct functional groups such as azide, hydroxy, and alkyne, as well as coordinative functional end groups (carboxylic acid or pyridine) combined in a single oligoarene molecular unit at strategic positions offer an advantageous dual-utility. First, these compounds can serve as useful molecular bricks (ditopic organic linkers) in the construction of complex porous crystalline materials. Second, after the assembly into the crystalline coordination networks, orthogonal functional sites within the linker-backbone offer tremendous potential from application perspectives as they can be modified by a wide range of post-synthetic modifications including azide–alkyne click chemistry. This allows further tailoring of the supramolecular assemblies to yield novel multifunctional materials.
- Grosjean, Sylvain,Hassan, Zahid,W?ll, Christof,Br?se, Stefan
-
p. 1446 - 1460
(2018/10/24)
-
- Ex2box: Interdependent modes of binding in a two-nanometer-long synthetic receptor
-
Incorporation of two biphenylene-bridged 4,4′-bipyridinium extended viologen units into a para-phenylene-based cyclophane results in a synthetic receptor that is ~2 nm long and adopts a box-like geometry. This cyclophane, Ex2Box4+, possesses the ability to form binary and ternary complexes with a myriad of guest molecules ranging from long π-electron-rich polycyclic aromatic hydrocarbons, such as tetracene, tetraphene, and chrysene, to π-electron-poor 2,6-dinitrotoluene, 1,2,4-trichlorobenzene, and both the 9,10- and 1,4-anthraquinone molecules. Moreover, Ex2Box4+ is capable of forming one-to-one complexes with polyether macrocycles that consist of two π-electron-rich dioxynaphthalene units, namely, 1,5-dinaphtho[38]crown-10. This type of broad molecular recognition is possible because the electronic constitution of Ex 2Box4+ is such that the pyridinium rings located at the ends of the cyclophane are electron-poor and prefer to enter into donor-acceptor interactions with π-electron-rich guests, while the middle of the cyclophane, consisting of the biphenylene spacer, is more electron-rich and can interact with π-electron-poor guests. In some cases, these different modes of binding can act in concert to generate one-to-one complexes which possess high stability constants in organic media. The binding affinity of Ex2Box4+ was investigated in the solid state by way of single-crystal X-ray diffraction and in solution by using UV-vis and NMR spectroscopy for 12 inclusion complexes consisting of the tetracationic cyclophane and the corresponding guests of different sizes, shapes, and electronic compositions. Additionally, density functional theory was carried out to elucidate the relative energetic differences between the different modes of binding of Ex2Box4+ with anthracene, 9,10-anthraquinone, and 1,4-anthraquinone in order to understand the degree with which each mode of binding contributes to the overall encapsulation of each guest.
- Juricek, Michal,Barnes, Jonathan C.,Dale, Edward J.,Liu, Wei-Guang,Strutt, Nathan L.,Bruns, Carson J.,Vermeulen, Nicolaas A.,Ghooray, Kala C.,Sarjeant, Amy A.,Stern, Charlotte L.,Botros, Youssry Y.,Goddard, William A.,Stoddart, J. Fraser
-
supporting information
p. 12736 - 12746
(2013/09/23)
-
- Using host-guest complexation to fold a flexible linear organic string: Kinetically controlled syntheses of [3]catenanes and a five-membered molecular necklace
-
Rings and necklaces: Three [3]catenanes and a five-membered molecular necklace ([5]MN), with up to 60- and 92-membered rings as their centerpieces, respectively, have been synthesized. The synthesis started from the corresponding complexes in which the threaded flexible linear guests were bent at approximately right angles to facilitate kinetically controlled macrocyclizations. Copyright
- Chang, Chia-Fong,Chuang, Chun-Ju,Lai, Chien-Chen,Liu, Yi-Hung,Peng, Shie-Ming,Chiu, Sheng-Hsien
-
supporting information
p. 10094 - 10098
(2012/11/13)
-
- NANOFIBERS FROM FUNCTIONALIZED ORGANIC MOLECULES
-
The present invention relates to organic nanofibers that can be produced from organic compounds having a core according to formula (I), wherein X and/or Y are C or N and n is 2 to 4 by self-organized growth on a solid substrate upon deposition from the ga
- -
-
Page/Page column 10
(2008/06/13)
-
- Syntheses and photophysical properties of some 4-arylpyridinium salts
-
A number of 4-arylpyridines, many methoxy substituted, were prepared by an efficient two-step method involving aryl Grignard addition to 1-methyl-4-piperidone and direct aromatization of the resulting 4-aryl-4-piperidinols. The pyridines were N-alkylated to give sulfonate salts desired for their fluorescent properties. Study of selected compounds as laser dyes revealed several structures to be efficient dyes lasing in the 530-550 nm range. Two new diazaquaterphenyls were prepared and were quaternized. These salts exhibited intense fluorescence in the 420-450 nm range, but would not lase. A phenolic azaterphenyl suitably substituted for excited state intramolecular proton transfer (ESIPT) did not fluoresce at all.
- Kelley,Ansu,Budisusetyo,Ghiorghis,Qin,Kauffman
-
-