Coulombic interactions, hydrogen bonding and supramolecular chirality in pyridinium trifluoromethanesulfonate

2009 ◽  
Vol 65 (10) ◽  
pp. o509-o511 ◽  
Author(s):  
Israel Goldberg
Nano Research ◽  
2021 ◽  
Author(s):  
Jinying Liu ◽  
Yu Zhao ◽  
Changli Zhao ◽  
Xiaoqiu Dou ◽  
Xiaoyu Ma ◽  
...  

2016 ◽  
Vol 72 (7) ◽  
pp. 1050-1053 ◽  
Author(s):  
Najla Mahbouli Rhouma ◽  
Ali Rayes ◽  
Francesco Mezzadri ◽  
Gianluca Calestani ◽  
Mohamed Loukil

The structure of the title non-centrosymmetric organic–inorganic hybrid salt, (C8H12NO)2[ZnCl4], consists of two 4-methoxybenzylammonium cations sandwiched between anionic layers, formed by isolated tetrachloridozincate tetrahedra. The double layers extend parallel to theacplane. The crystal packing is assured by Coulombic interactions and by a complex N—H...Cl and C—H...Cl hydrogen-bonding system mostly involving the positively charged ammonium groups and the chloride ligands of the isolated tetrahedral [ZnCl4]2−units. One of the methyleneammonium groups is disordered over two sets of sites in a 0.48 (2):0.52 (2) ratio. The crystal investigated was twinned by non-merohedry with a twin component ratio of 0.738 (2):0.262 (2).


Molecules ◽  
2020 ◽  
Vol 25 (3) ◽  
pp. 721 ◽  
Author(s):  
Young-Ho Oh ◽  
Hyoju Choi ◽  
Chanho Park ◽  
Dong Wook Kim ◽  
Sungyul Lee

We review recent works for nucleophilic fluorination of organic compounds in which the Coulombic interactions between ionic species and/or hydrogen bonding affect the outcome of the reaction. SN2 fluorination of aliphatic compounds promoted by ionic liquids is first discussed, focusing on the mechanistic features for reaction using alkali metal fluorides. The influence of the interplay of ionic liquid cation, anion, nucleophile and counter-cation is treated in detail. The role of ionic liquid as bifunctional (both electrophilic and nucleophilic) activator is envisaged. We also review the SNAr fluorination of diaryliodonium salts from the same perspective. Nucleophilic fluorination of guanidine-containing of diaryliodonium salts, which are capable of forming hydrogen bonds with the nucleophile, is exemplified as an excellent case where ionic interactions and hydrogen bonding significantly affect the efficiency of reaction. The origin of experimental observation for the strong dependence of fluorination yields on the positions of -Boc protection is understood in terms of the location of the nucleophile with respect to the reaction center, being either close to far from it. Recent advances in the synthesis of [18F]F-dopa are also cited in relation to SNAr fluorination of diaryliodonium salts. Discussions are made with a focus on tailor-making promoters and solvent engineering based on ionic interactions and hydrogen bonding.


2003 ◽  
Vol 07 (02) ◽  
pp. 112-119 ◽  
Author(s):  
Chiara Fanti ◽  
Donato Monti ◽  
Laura La Monica ◽  
Francesca Ceccacci ◽  
Giovanna Mancini ◽  
...  

A ternary self-assembling system consisting of two Zn(II) carboxyphenylporphyrins and an aliphatic diamine linker was constructed via hydrogen bonding and Coulombic interactions between the porphyrin carboxylic moieties and the amino groups of the spacer. The properties of the resulting structures, in terms of binding of several aromatic diamine guests are described. The stability and geometry of the final host-guest supramolecular architecture (i.e. cyclic or linear array) can be modulated by the nature of the spacer.


Author(s):  
Aleksej Jochim ◽  
Inke Jess ◽  
Christian Näther

The crystal structure of the title salt, (C6H8NO)8[Fe(NCS)4(C6H7NO)2][Fe(NCS)5(C6H7NO)]2[Fe(NCS)6], comprises three negatively charged octahedral FeIIIcomplexes with different coordination environments in which the FeIIIatoms are coordinated by a different number of thiocyanate anions and 4-methoxypyridine ligands. Charge balance is achieved by 4-methoxypyridinium cations. The asymmetric unit consists of three FeIIIcations, one of which is located on a centre of inversion, one on a twofold rotation axis and one in a general position, and ten thiocyanate anions, two 4-methoxypyridine ligands and 4-methoxypyridinium cations (one of which is disordered over two sets of sites). Beside to Coulombic interactions between organic cations and the ferrate(III) anions, weak N—H...S hydrogen-bonding interactions involving the pyridinium N—H groups of the cations and the thiocyanate S atoms of the complex anions are mainly responsible for the cohesion of the crystal structure.


1999 ◽  
Vol 55 (3) ◽  
pp. 389-395 ◽  
Author(s):  
Ping Zhou ◽  
Feng Xue ◽  
Steve C. F. Au-Yeung ◽  
Xiao-ping Xu

The crystal structures of [18]aneN6H2K[Co(CN)6].4H2O [potassium dihydrogen hexacyanocobaltate–1,4,7,10,13,16-hexaazacyclooctadecane–water (1/1/4)], [16]aneN4H2K[Co(CN)6] [potassium dihydrogen hexacyanocobaltate–1,5,9,13-tetraazacyclohexadecane (1/1)] and [12]aneN4H3[Co(CN)6].2H2O [trihydrogen hexacyanocobaltate–1,4,7,10-tetraazacyclododecane–water (1/1/2)] have been determined. For these supercomplexes, the [Co(CN)6]3− binding with protonated polyammonium macrocycles is dominant in the binding competition between K+ and [Co(CN)6]3−. It is suggested that the binding of [Co(CN)6]3− with protonated polyammonium macrocycles is independent of the cavity size of the macrocycle, whereas that of K+ is size-match selective. For [18]aneN6H2K[Co(CN)6].4H2O, the formation of a two-dimensional lamella may be derived from a chain-like arrangement of four-, five- and eight-membered rings in the network through the mutual balance between electrostatic and hydrogen-bonding interactions. [16]aneN4H2K[Co(CN)6] is a novel example demonstrating the anchoring of cobalticyanide through hydrogen-bonding interactions inside a zeolite-type cavity in the three-dimensional network formed by K+ and the macrocycles through Coulombic interactions. Also, a three-dimensional network was formed mainly through hydrogen-bonding interactions between [Co(CN)6]3−, protonated macrocycles and water molecules in [12]aneN4H3[Co(CN)6].2H2O.


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