Synthesis of Organic Photodimeric Cage Molecules Based on Cycloaddition via Metal−Ligand Directed Assembly

Two novel three-dimensional Zn-MOFs (zinc metal-organic frameworks), Zn5(μ3-OH)(BTC)3(Phen)4·5H2O (denoted as HUT-11) and Zn4(μ4-O)(BTC)2(Phen)2·4H2O (denoted as HUT-12), have been synthesized by metal–ligand-directed assembly under hydrothermal conditions. Here, BTC and Phen are denoted as 1,3,5-benzenetricarboxylate and phenanthroline. HUT-11 contains two kinds of secondary building units (SBUs), Zn3(μ3-OH)(COO)5 clusters and Zn2(COO)4 clusters. This material exhibits a new three-dimensional (3,4,5)-connected topology with the Schläfli symbol (4·6·8)2(4·82)(4·64·85)(42·62·82). Two perpendicular planes cross at five coordinated Zn1—Zn3—Zn5 nodes, giving a new three-dimensional network. HUT-12 is composed of Zn4(μ4-O)(COO)6 clusters as the secondary building units and displays a two-dimensional (3,6)-connected TiS2 related net topology with the Schläfli symbol (42·6)(44·62·88·10). Both MOFs show blue light emission and a high thermal stability above 673 K.

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Directed Assembly of Nanowires using Silicon Grooves and Localized Surface Treatments

10.1557/proc-1144-ll20-11 ◽

2008 ◽

Author(s):

Sabrina Habtoun ◽

Christian Bergaud ◽

Monique Dilhan ◽

David Bourrier

Keyword(s):

Directed Assembly ◽

Surface Treatments

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Controlling Gas Selectivity in Molecular Porous Liquids by Tuning the Cage Window Size

10.26434/chemrxiv.10247528.v1 ◽

2019 ◽

Author(s):

Benjamin Egleston ◽

Konstantin V. Luzyanin ◽

Michael C. Brand ◽

Rob Clowes ◽

Michael E. Briggs ◽

...

Keyword(s):

Nmr Spectroscopy ◽

Chemical Synthesis ◽

Field Gradient ◽

Window Size ◽

Standard Approach ◽

Porous Solids ◽

Pulsed Field Gradient Nmr ◽

Pulsed Field ◽

Cage Molecules ◽

Gas Selectivity

Control of pore window size is the standard approach for tuning gas selectivity in porous solids. Here, we present the first example where this is translated into a molecular porous liquid formed from organic cage molecules. Reduction of the cage window size by chemical synthesis switches the selectivity from Xe-selective to CH<sub>4</sub>-selective, which is understood using <sup>129</sup>Xe, <sup>1</sup>H, and pulsed-field gradient NMR spectroscopy.

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Controlling Gas Selectivity in Molecular Porous Liquids by Tuning the Cage Window Size

10.26434/chemrxiv.10247528 ◽

2019 ◽

Author(s):

Benjamin Egleston ◽

Konstantin V. Luzyanin ◽

Michael C. Brand ◽

Rob Clowes ◽

Michael E. Briggs ◽

...

Keyword(s):

Nmr Spectroscopy ◽

Chemical Synthesis ◽

Field Gradient ◽

Window Size ◽

Standard Approach ◽

Porous Solids ◽

Pulsed Field Gradient Nmr ◽

Pulsed Field ◽

Cage Molecules ◽

Gas Selectivity

Control of pore window size is the standard approach for tuning gas selectivity in porous solids. Here, we present the first example where this is translated into a molecular porous liquid formed from organic cage molecules. Reduction of the cage window size by chemical synthesis switches the selectivity from Xe-selective to CH<sub>4</sub>-selective, which is understood using <sup>129</sup>Xe, <sup>1</sup>H, and pulsed-field gradient NMR spectroscopy.

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Enhanced-Fluorescence of a Dye on DNA- assembled Gold Nano-Dimers Discriminated by Lifetime Correlation Spectroscopy

10.26434/chemrxiv.5728446.v1 ◽

2017 ◽

Author(s):

Pedro M. R. Paulo ◽

David Botequim ◽

Agnieszka Jóskowiak ◽

Sofia Martins ◽

Duarte M. F. Prazeres ◽

...

Keyword(s):

Single Molecule ◽

Fluorescence Emission ◽

Directed Assembly ◽

Plasmon Mode ◽

Correlation Spectroscopy ◽

Enhanced Fluorescence ◽

Detection Volume ◽

Relaxation Component ◽

Good Agreement ◽

Confocal Detection

<div> <div> <div> <p>We have employed DNA-directed assembly to prepare dimers of gold nanoparticles and used their longitudinally coupled plasmon mode to enhance the fluorescence emission of an organic red-emitting dye, Atto-655. The plasmon- enhanced fluorescence of this dye using dimers of 80 nm particles was measured at single molecule detection level. The top enhancement factors were above 1000-fold in 71% of the dimers within a total of 32 dimers measured, and, in some cases, they reached almost 4000-fold, in good agreement with model simulations. Additionally, fluorescence lifetime correlation analysis enabled the separation of enhanced from non-enhanced emission simultaneously collected in our confocal detection volume. This approach allowed us to recover a short relaxation component exclusive to enhanced emission that is attributed to the interaction of the dye with DNA in the interparticle gaps. </p> </div> </div> </div>

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