Single-Crystal Uniform Tubes of ZnO

2007 ◽  
Vol 121-123 ◽  
pp. 801-804 ◽  
Author(s):  
L.Q. Zhou ◽  
Ying Dai ◽  
Yue Ling Sun ◽  
Wen Chen
Keyword(s):  
Low Temperature ◽  
Single Crystal ◽  
Crystal Structures ◽  
Growth Mechanism ◽  
Hydrothermal Process ◽  
High Yield ◽  
Processing Conditions ◽  
Single Crystal Structures ◽  
Cheap Method

A simple and cheap method has been applied to synthesize single-crystal uniform ZnO tubes with high yield in a hydrothermal process using Zn(NO3)2⋅6H2O and methenamine as reaction precursors at low temperature. The products are characterized by XRD, SEM, TEM and SAED. ZnO tubes are uniform single-crystal structures and grow along the [0001] direction. They have straight and regular hexagonal configuration with faceted ends and slippery side surfaces. The growth mechanism of ZnO tubes is investigated and the processing conditions are critical for the formation of ZnO tubes.

scholarly journals Manipulating the Conformation of 3,2′:6′,3″-Terpyridine in [Cu2(μ-OAc)4(3,2′:6′,3″-tpy)]n 1D-Polymers

Chemistry ◽  
2021 ◽  
Vol 3 (1) ◽  
pp. 182-198
Author(s):  
Dalila Rocco ◽  
Samantha Novak ◽  
Alessandro Prescimone ◽  
Edwin C. Constable ◽  
Catherine E. Housecroft
Keyword(s):  
Single Crystal ◽  
Crystal Structures ◽  
Metal Binding ◽  
Polymer Chains ◽  
X Ray Diffraction ◽  
Face To Face ◽  
Single Crystal Structures ◽  
Π Stacking ◽  
Metal Binding Domain ◽  
Packing Interactions

We report the preparation and characterization of 4′-([1,1′-biphenyl]-4-yl)-3,2′:6′,3″-terpyridine (1), 4′-(4′-fluoro-[1,1′-biphenyl]-4-yl)-3,2′:6′,3″-terpyridine (2), 4′-(4′-chloro-[1,1′-biphenyl]-4-yl)-3,2′:6′,3″-terpyridine (3), 4′-(4′-bromo-[1,1′-biphenyl]-4-yl)-3,2′:6′,3″-terpyridine (4), and 4′-(4′-methyl-[1,1′-biphenyl]-4-yl)-3,2′:6′,3″-terpyridine (5), and their reactions with copper(II) acetate. Single-crystal structures of the [Cu2(μ-OAc)4L]n 1D-coordination polymers with L = 1–5 have been determined, and powder X-ray diffraction confirms that the single crystal structures are representative of the bulk samples. [Cu2(μ-OAc)4(1)]n and [Cu2(μ-OAc)4(2)]n are isostructural, and zigzag polymer chains are present which engage in π-stacking interactions between [1,1′-biphenyl]pyridine units. 1D-chains nest into one another to give 2D-sheets; replacing the peripheral H in 1 by an F substituent in 2 has no effect on the solid-state structure, indicating that bifurcated contacts (H...H for 1 or H...F for 2) are only secondary packing interactions. Upon going from [Cu2(μ-OAc)4(1)]n and [Cu2(μ-OAc)4(2)]n to [Cu2(μ-OAc)4(3)]n, [Cu2(μ-OAc)4(4)]n, and [Cu2(μ-OAc)4(5)]n·nMeOH, the increased steric demands of the Cl, Br, or Me substituent induces a switch in the conformation of the 3,2′:6′,3″-tpy metal-binding domain, and a concomitant change in dominant packing interactions to py–py and py–biphenyl face-to-face π-stacking. The study underlines how the 3,2′:6′,3″-tpy domain can adapt to different steric demands of substituents through its conformational flexibility.

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