scholarly journals Self-assembly of heteroleptic dinuclear metallosupramolecular kites from multivalent ligands via social self-sorting

2015 ◽  
Vol 11 ◽  
pp. 693-700 ◽  
Author(s):  
Christian Benkhäuser ◽  
Arne Lützen

A Tröger's base-derived racemic bis(1,10-phenanthroline) ligand (rac)-1 and a bis(2,2'-bipyridine) ligand with a central 1,3-diethynylbenzene unit 2 were synthesized. Each of these ligands acts as a multivalent entity for the binding of two copper(I) ions. Upon coordination to the metal ions these two ligands undergo selective self-assembly into heteroleptic dinuclear metallosupramolecular kites in a high-fidelity social self-sorting manner as evidenced by NMR spectroscopy and mass spectrometry.

2011 ◽  
Vol 89 (7) ◽  
pp. 835-844 ◽  
Author(s):  
Irene C.M. Kwan ◽  
Yi-Min She ◽  
Gang Wu

We report structural determination of cation-templated self-assembly of a guanosine derivative, 2′,3′,5′-O-triacetylguanosine (TAG), in the presence of three alkaline earth metal ions (Ca2+, Sr2+, and Ba2+) in CDCl3. Using a combination of nuclear magnetic resonance (NMR) and electrospray ionization mass spectrometry (ESI-MS) methods, we have found that TAG molecules form discrete octamers in the form of [TAG]8M2+ (M2+ = Ca2+, Sr2+, and Ba2+), which is composed of two G-quartets and a sandwiched metal ion. We have determined the ability of the three alkaline earth metal ions to promote TAG self-assembly (relative binding affinity) to be Sr2+ ≫ Ba2+ > Ca2+. More importantly, we have used two-dimensional (2D) NMR methods to determine the structural details of [TAG]8Sr2+. In particular, we found that each octamer consists of an all-anti G-quartet stacking on top of an all-syn G-quartet in a tail-to-head fashion with a twist angle of 45° between the two G-quartets. This TAG octamer structure represents a unique case quite different from other lipophilic guanosine octamers reported in the literature.


2010 ◽  
Vol 2010 ◽  
pp. 1-8 ◽  
Author(s):  
Anupam Khutia ◽  
Pablo J. Sanz Miguel ◽  
Bernhard Lippert

The flexible ditopic ligand 3,-bipyridine (3,-bpy) has been reacted with a series of transition metal species (A, H, cis- ( or ; ), trans- ()) in an attempt to produce discrete cyclic constructs. While A gave a polymeric structure [Ag(3,-bpy)](Cl)   (1), with all other metal entities cyclic structures were formed. Interestingly, Hg(CCOO produced a dinuclear complex [Hg(3,-bpy)(CCOO  3O (2), in which the two 3,-bpy ligands adopt a cis-orientation of the coordinating pyridyl entities. With cis-(, a cyclic complex4was isolated in crystalline form which, according to HRMS, is a trimer. With trans-(, different species are formed according to NMR spectroscopy, the nature of which was not established.


2014 ◽  
Vol 10 ◽  
pp. 432-441 ◽  
Author(s):  
Rainer Hovorka ◽  
Sophie Hytteballe ◽  
Torsten Piehler ◽  
Georg Meyer-Eppler ◽  
Filip Topić ◽  
...  

Two new 9,9’-spirobifluorene-based bis(4-pyridines) were synthesised in enantiopure and one also in racemic form. These ligands act as concave templates and form metallosupramolecular [(dppp)2M2L2] rhombi with cis-protected [(dppp)Pd]2+ and [(dppp)Pt]2+ ions. The self-assembly process of the racemic ligand preferably occurs in a narcissistic self-recognising manner. Hence, a mixture of all three possible stereoisomers [(dppp)2M2{(R)-L}2](OTf)4, [(dppp)2M2{(S)-L}2](OTf)4, and [(dppp)2M2{(R)-L}{(S)-L}](OTf)4 was obtained in an approximate 1.5:1.5:1 ratio which corresponds to an amplification of the homochiral assemblies by a factor of approximately three as evidenced by NMR spectroscopy and mass spectrometry. The racemic homochiral assemblies could also be characterised by single crystal X-ray diffraction.


2011 ◽  
Vol 317-319 ◽  
pp. 2306-2309
Author(s):  
Lu Yuan ◽  
Hong Zhong ◽  
Li Qing Li

The synthesis, characterization, and its coordination with metal ions of a novel thiourea N,N'-diethoxycarbonyl-N'',N' ''-(1,2-propylidene) dithiourea was reported. The structure of the prepared compound was determined by elemental analysis, infrared spectrum, mass spectrometry, 1H NMR and 13C NMR spectroscopy. Its coordination with metal ions such as Cu2+, Ni2+, Fe3+ was investigated by uv-vis spectrophotometer. The results show that this dithiourea with new structure can react with Cu2+ and Ni2+ separately, and has a best selectivity to Fe3+ ion. Bench-scale flotation tests were also carried out, verifying it has higher copper flotation recovery compared with universal collectors and better selectivity to sulphur.


2008 ◽  
Vol 59 (1) ◽  
pp. 41-44
Author(s):  
Maria-Daniela Sofei ◽  
Maria Ilici ◽  
Valentin Badea ◽  
Carol Csunderlik ◽  
Vasile-Nicolae Bercean

The synthesis of 1H-3-aryl-7-ethoxycarbonyl-6-methyl-pyrazolo[5,1-c][1,2,4]triazoles (2) was carried out by cyclization of 1H-5-arylidenehydrazino-4-ethoxycarbonyl-3-methyl-pyrazoles (1) in the presence of bromine using glacial acetic acid as solvent and sodium acetate as base. The new nine obtained compounds were characterized by IR and NMR spectroscopy and mass spectrometry.


1983 ◽  
Vol 48 (7) ◽  
pp. 1864-1866
Author(s):  
Jan Bartoň ◽  
Ivan Kmínek

2,7-Dimethyl-2,6-octadiene is formed in the catalytic solution for the dimerization of 2-methyl-1,3-butadiene to β-myrcene (3-methylene-7-methyl-1,6-octadiene), as revealed by mass spectrometry and 13C NMR spectroscopy. Visual observations together with the results of gas chromatographic analysis of the catalytic solution suggest that the formation of 2,7-dimethyl-2,6-octadiene is associated with the transition of the alkali metal (sodium) from the solid phase into the solution. A reaction pathway is suggested accounting for the formation of 2,7-dimethyl-2,6-octadiene in the system.


1993 ◽  
Vol 58 (8) ◽  
pp. 1914-1918 ◽  
Author(s):  
Jaroslav Kříž ◽  
Luděk Taimr

The structure of a new compound formed in the reaction of ethoxyquin with alkylperoxy radicals was resolved by 1H and 13C NMR spectroscopy (including COSY, NOESY, HHC RCT and SSLR INEPT techniques) and confirmed by mass spectrometry. The structure suggest participation of 4-methyl group of ethoxyquin in the deactivation of peroxy radicals. A mechanism of this reaction is proposed.


Molbank ◽  
10.3390/m1140 ◽  
2020 ◽  
Vol 2020 (2) ◽  
pp. M1140
Author(s):  
Jack Bennett ◽  
Paul Murphy

(2S,3R,6R)-2-[(R)-1-Hydroxyallyl]-4,4-dimethoxy-6-methyltetrahydro-2H-pyran-3-ol was isolated in 18% after treating the glucose derived (5R,6S,7R)-5,6,7-tris[(triethylsilyl)oxy]nona-1,8-dien-4-one with (1S)-(+)-10-camphorsulfonic acid (CSA). The one-pot formation of the title compound involved triethylsilyl (TES) removal, alkene isomerization, intramolecular conjugate addition and ketal formation. The compound was characterized by 1H and 13C NMR spectroscopy, ESI mass spectrometry and IR spectroscopy. NMR spectroscopy was used to establish the product structure, including the conformation of its tetrahydropyran ring.


Molbank ◽  
10.3390/m1250 ◽  
2021 ◽  
Vol 2021 (3) ◽  
pp. M1250
Author(s):  
Diana Becerra ◽  
Justo Cobo ◽  
Juan-Carlos Castillo

We report the ambient-temperature synthesis of novel (E)-N-(3-(tert-butyl)-1-methyl-1H-pyrazol-5-yl)-1-(pyridin-2-yl)methanamine 3 in 81% yield by a condensation reaction between 3-(tert-butyl)-1-methyl-1H-pyrazol-5-amine 1 and 2-pyridinecarboxaldehyde 2 in methanol using magnesium sulfate as a drying agent. The N-pyrazolyl imine 3 was full characterized by IR, 1D, and 2D NMR spectroscopy, mass spectrometry, and elemental analysis.


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