Formation of Cylindrical-Shaped Coordination Polymer by Self-Assembling of 2, 2, 4, 4, 6, 6-Hexakis(4-pyridylmethoxy)-2λ5, 4λ5, 6λ5-cyclotri(phosphazene) with Silver Nitrate

2000 ◽  
Vol 73 (11) ◽  
pp. 2615-2619 ◽  
Author(s):  
Tomoyuki Itaya ◽  
Kenzo Inoue
Author(s):  
Tokouré Assoumatine ◽  
Helen Stoeckli-Evans

The two new pyrazineophanes, 5,7-dihydro-1H,3H-dithieno[3,4-b:3′,4′-e]pyrazine, C8H8N2S2, L1, and 3,4,8,10,11,13-hexahydro-1H,6H-bis([1,4]dithiocino)[6,7-b:6′,7′-e]pyrazine, C12H16N2S4, L2, both crystallize with half a molecule in the asymmetric unit; the whole molecules are generated by inversion symmetry. The molecule of L1, which is planar (r.m.s. deviation = 0.008 Å), consists of two sulfur atoms linked by a rigid tetra-2,3,5,6-methylenepyrazine unit, forming planar five-membered rings. The molecule of L2 is step-shaped and consists of two S–CH2–CH2–S chains linked by the central rigid tetra-2,3,5,6-methylenepyrazine unit, forming eight-membered rings that have twist-boat-chair configurations. In the crystals of both compounds, there are no significant intermolecular interactions present. The reaction of L1 with silver nitrate leads to the formation of a two-dimensional coordination polymer, poly[(μ-5,7-dihydro-1H,3H-dithieno[3,4-b;3′,4′-e]pyrazine-κ2 S:S′)(μ-nitrato-κ2 O:O′)silver(I)], [Ag(NO3)(C8H8N2S2)] n , (I), with the nitrato anion bridging two equivalent silver atoms. The central pyrazine ring is situated about an inversion center and the silver atom lies on a twofold rotation axis that bisects the nitrato anion. The silver atom has a fourfold AgO2S2 coordination sphere with a distorted shape. The reaction of L2 with silver nitrate also leads to the formation of a two-dimensional coordination polymer, poly[[μ33,4,8,10,11,13-hexahydro-1H,6H-bis([1,4]dithiocino)[6,7-b;6′,7′-e]pyrazine-κ3 S:S′:S′′](nitrato-κO)silver(I)], [Ag(NO3)(C12H16N2S4)] n , (II), with the nitrate anion coordinating in a monodentate manner to the silver atom. The silver atom has a fourfold AgOS3 coordination sphere with a distorted shape. In the crystals of both complexes, the networks are linked by C—H...O hydrogen bonds, forming supramolecular frameworks. There are additional C—H...S contacts present in the supramolecular framework of II.


2020 ◽  
Vol 49 (10) ◽  
pp. 1228-1231
Author(s):  
Midori Murakami ◽  
Riku Matsumine ◽  
Takeya Ono ◽  
Katsuaki Konishi

2006 ◽  
Vol 59 (1) ◽  
pp. 19 ◽  
Author(s):  
Christopher M. Fitchett ◽  
Peter J. Steel

The chiral bridging ligand 2 is shown to react with silver nitrate to produce a new type of chiral coordination polymer with a unidirectional ladder-like structure.


RSC Advances ◽  
2018 ◽  
Vol 8 (37) ◽  
pp. 20829-20835 ◽  
Author(s):  
Fang Wu ◽  
Dengfeng He ◽  
Lei Chen ◽  
Fangqin Liu ◽  
Haolong Huang ◽  
...  

Herein, antibacterial coordination polymer hydrogels were conveniently fabricated in water via coordination between silver nitrate and PEGylated bisimidazolylbenzyl alcohol (1a–c).


Author(s):  
George C. Ruben ◽  
Kenneth A. Marx

Certain double stranded DNA bacteriophage and viruses are thought to have their DNA organized into large torus shaped structures. Morphologically, these poorly understood biological DNA tertiary structures resemble spermidine-condensed DNA complexes formed in vitro in the total absence of other macromolecules normally synthesized by the pathogens for the purpose of their own DNA packaging. Therefore, we have studied the tertiary structure of these self-assembling torus shaped spermidine- DNA complexes in a series of reports. Using freeze-etch, low Pt-C metal (10-15Å) replicas, we have visualized the microscopic DNA organization of both calf Thymus( CT) and linear 0X-174 RFII DNA toruses. In these structures DNA is circumferentially wound, continuously, around the torus into a semi-crystalline, hexagonal packed array of parallel DNA helix sections.


Author(s):  
K. Chien ◽  
R.C. Heusser ◽  
M.L. Jones ◽  
R.L. Van de Velde

Silver impregnation techniques have been used for the demonstration of the complex carbohydrates in electron microscopy. However, the silver stains were believed to be technically sensitive and time consumming to perform. Currently, due to the need to more specifically evaluate immune complex for localization in certain renal diseases, a simplified procedure in conjunction with the use of the microwave has been developed and applied to renal and other biopsies. The procedure is as follows:Preparation of silver methenamine solution:1. 15ml graduated, clear polystyrene centrifuge tube (Falcon, No. 2099) was rinsed once with distilled water.2. 3% hexamethylene tetramine (methenamine) was added into the centrifuge tube to the 6ml mark.3. 3% silver nitrate was added slowly to the methenamine to the 7ml mark while agitating. (Solution will instantly turn milky in color and then clear rapidly by mixing. No precipitate should be formed).4. 2% sodium borate was added to the solution to the 8ml mark, mixed and centrifuged before use.


2003 ◽  
Vol 56 (8) ◽  
pp. 647-653 ◽  
Author(s):  
Lan Liu ◽  
Stan Duraj ◽  
Phillip E. Fanwick ◽  
Maria T. Andras ◽  
Aloysius F. Hepp

2020 ◽  
Author(s):  
Will R Henderson ◽  
Danielle E. Fagnani ◽  
Yu Zhu ◽  
Guancen Liu ◽  
Ronald K. Castellano

Nature ◽  
1999 ◽  
Author(s):  
Philip Ball
Keyword(s):  

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