- Toward long-distance mechanical communication: Studies on a ternary complex interconnected by a bridging rotary module
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A heterotropic ternary complex was obtained from a photochromic dithienylethene derivative bearing pyridyl groups (1), a chiral tetrasubstituted ferrocene as a scissoring component bearing two pyridyl and free-base porphyrin groups (3*), and a biaryl derivative as an intermediately bridging component bearing four zinc porphyrin handles (2). The three components are connected together via bidentate coordination bonds and mechanically interconnected. Exposure of the ternary complex to UV or visible light allowed for the isomerization of 1. This configurational change gave rise to an angular motion of 2, resulting in a scissoring motion of 3*. In the absence of 2, the isomerization of 1 does not lead to any defined motions of 3*. Thus, the heterotropic ternary complex may be regarded as a prototype of molecular reacher for remote manipulation of molecular events. Copyright
- Kai, Hiroyuki,Nara, Shinji,Kinbara, Kazushi,Aida, Takuzo
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- Non-Catalytic Benefits of Ni(II) Binding to an Si(111)-PNP Construct for Photoelectrochemical Hydrogen Evolution Reaction: Metal Ion Induced Flat Band Potential Modulation
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We report here the remarkable and non-catalytic beneficial effects of a Ni(II) ion binding to a Si|PNP type surface as a result of significant thermodynamic band bending induced by ligand attachment and Ni(II) binding. We unambiguously deconvolute the thermodynamic flat band potentials (VFB) from the kinetic onset potentials (Von) by synthesizing a specialized bis-PNP macrochelate that enables one-step Ni(II) binding to a p-Si(111) substrate. XPS analysis and rigorous control experiments confirm covalent attachment of the designed ligand and its resulting Ni(II) complex. Illuminated J-V measurements under catalytic conditions show that the Si|BisPNP-Ni substrate exhibits the most positive onset potential for the hydrogen evolution reaction (HER) (-0.55 V vs Fc/Fc+) compared to other substrates herein. Thermodynamic flat band potential measurements in the dark reveal that Si|BisPNP-Ni also exhibits the most positive VFB value (-0.02 V vs Fc/Fc+) by a wide margin. Electrochemical impedance spectroscopy data generated under illuminated, catalytic conditions demonstrate a surprising lack of correlation evident between Von and equivalent circuit element parameters commonly associated with HER. Overall, the resulting paradigm comprises a system wherein the extent of band bending induced by metal ion binding is the primary driver of photoelectrochemical (PEC)-HER benefits, while the kinetic (catalytic) effects of the PNP-Ni(II) are minimal. This suggests that dipole and band-edge engineering must be a primary design consideration (not secondary to catalyst) in semiconductor|catalyst hybrids for PEC-HER.
- Gurrentz, Joseph M.,Rose, Michael J.
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- Introducing High Density of Very Active Sites and Stepwise Postmodification for Tailoring the Porosity of Highly Demanding Cr3+-Based Metal-Organic Frameworks
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Chromium(III)-based metal-organic frameworks (Cr-MOFs) are highly robust and porous and have been very attractive in a wide range of investigations. However, the harsh direct synthetic conditions not only impede the synthesis of new Cr-MOFs but also restr
- Wang, Jun-Hao,Shi, Chun-Yang,Li, Meng-Na,Zhang, Ying,Niu, Jian-Chao,Zhang, Xian-Ming,Zhao, Ya-Wen,Li, Dan
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p. 12109 - 12115
(2021/08/20)
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- A mild and convenient synthesis of 1,2,3-triiodoarenes via consecutive iodination/diazotization/iodination strategy
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A mild and convenient synthesis of 1,2,3-triiodoarenes has been developed. This method consists of two steps which can be performed on multigram scale with moderate to excellent yields. This report discloses a practical synthesis of 1,2,3-triiodoarenes and 1,2,3-trihaloarenes that is general in scope, operationally simple, scalable, and is easy to workup and to purify. We also report the first regioselective transmetalation reaction of 1,2,3-triiodoarenes to provide ortho-diiodoaryl derivatives, which are useful building blocks and indeed are hard to make by other means. CSIRO 2013.
- Al-Zoubi, Raed M.,Futouh, Hassan Abul,McDonald, Robert
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p. 1570 - 1575
(2014/01/23)
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- H-Bonding-driven gel formation of a phenylacetylene macrocycle
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An amide-containing phenylacetylene macrocycle (PAM) has been synthesized and its gelation properties were studied in different solvents. Surprisingly, this macrocycle forms organogels at low concentration in many polar and apolar solvents. XRD and FTIR analysis suggest that this macrocycle forms stable supramolecular assemblies owing to H-bonding. Scanning electron microscopy analyses show the formation of bundles of nanofibrils, demonstrating the long-range organization of this material.
- Cantin, Katy,Rondeau-Gagne, Simon,Neabo, Jules Romeo,Daigle, Maxime,Morin, Jean-Francois
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p. 4440 - 4443
(2011/07/30)
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- Synthesis of aryl/alkyl building blocks for dendrimer and hyperbranched polymer synthesis
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Several useful aryl/alkyl building blocks for dendrimer and hyperbranched polymer synthesis were prepared by Suzuki-Miyaura cross-coupling reactions and iododesilylation reactions. The iododesilylations were carried out with iodine monochloride (ICI) in m
- Bo, Zhishan,Qiu, Jun,Li, Jing,Schlueter, A. Dieter
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p. 667 - 669
(2007/10/03)
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- EPR probes with well-defined, long distances between two or three unpaired electrons
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The synthesis of rod- and star-shaped compounds carrying two or three spin labels as end groups is described. The unpaired electrons are 2.8-5.1 nm apart from each other. The shape-persistent scaffolds were obtained through Pd-Cu-catalyzed alkynyl-aryl coupling and Pd-Cu-catalyzed, alkyne dimerization in the presence of oxygen using p-phenyleneethynylene as the basic shape-persistent building block. The spin label 1-oxyl-2,2,5,5-tetramethylpyrroline-3-carboxylic acid (4) was attached through esterification of the terminal phenolic OH groups of the scaffold.
- Godt,Franzen,Veit,Enkelmann,Pannier,Jeschke
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p. 7575 - 7582
(2007/10/03)
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