Molecular Tectonics. Porous Hydrogen-Bonded Networks Built from Derivatives of Pentaerythrityl Tetraphenyl Ether

2004 ◽  
Vol 69 (6) ◽  
pp. 1776-1787 ◽  
Author(s):  
Dominic Laliberté ◽  
Thierry Maris ◽  
James D. Wuest
2004 ◽  
Vol 69 (6) ◽  
pp. 1762-1775 ◽  
Author(s):  
Jean-Hugues Fournier ◽  
Thierry Maris ◽  
James D. Wuest

2004 ◽  
Vol 37 (19) ◽  
pp. 7351-7357 ◽  
Author(s):  
Danielle Boils ◽  
Marie-Ève Perron ◽  
Francis Monchamp ◽  
Hugues Duval ◽  
Thierry Maris ◽  
...  

2018 ◽  
Vol 54 (8) ◽  
pp. 892-895 ◽  
Author(s):  
E. W. Dahl ◽  
H. T. Dong ◽  
N. K. Szymczak

A series of copper complexes bearing new 6-substituted tris(2-pyridylmethyl)amine ligands (LR) appended with NH(p-R-C6H4) groups (R = H, CF3, OMe) were prepared.


Author(s):  
Thomas Gelbrich ◽  
Denise Rossi ◽  
Ulrich J. Griesser

Polymorph (Ia) of eldoral [5-ethyl-5-(piperidin-1-yl)barbituric acid or 5-ethyl-5-(piperidin-1-yl)-1,3-diazinane-2,4,6-trione], C11H17N3O3, displays a hydrogen-bonded layer structure parallel to (100). The piperidine N atom and the barbiturate carbonyl group in the 2-position are utilized in N—H...N and N—H...O=C hydrogen bonds, respectively. The structure of polymorph (Ib) contains pseudosymmetry elements. The two independent molecules of (Ib) are connectedviaN—H...O=C(4/6-position) and N—H...N(piperidine) hydrogen bonds to give a chain structure in the [100] direction. The hydrogen-bonded layers, parallel to (010), formed in the salt diethylammonium 5-ethyl-5-(piperidin-1-yl)barbiturate [or diethylammonium 5-ethyl-2,4,6-trioxo-5-(piperidin-1-yl)-1,3-diazinan-1-ide], C4H12N+·C11H16N3O3−, (II), closely resemble the corresponding hydrogen-bonded structure in polymorph (Ia). Like many other 5,5-disubstituted derivatives of barbituric acid, polymorphs (Ia) and (Ib) contain theR22(8) N—H...O=C hydrogen-bond motif. However, the overall hydrogen-bonded chain and layer structures of (Ia) and (Ib) are unique because of the involvement of the hydrogen-bond acceptor function in the piperidine group.


2004 ◽  
Vol 82 (2) ◽  
pp. 386-398 ◽  
Author(s):  
Dominic Laliberté ◽  
Thierry Maris ◽  
James D Wuest

Tetraphenylmethane, tetraphenylsilane, and simple derivatives with substituents that do not engage in hydrogen bonding typically crystallize as close-packed structures with essentially no space available for the inclusion of guests. In contrast, derivatives with hydrogen-bonding groups are known to favor the formation of open networks that include significant amounts of guests. To explore this phenomenon, we synthesized six new derivatives 5a–5e and 6a of tetraphenylmethane and tetraphenylsilane with urethane and urea groups at the para positions, crystallized the compounds, and determined their structures by X-ray crystallography. As expected, all six compounds crystallize to form porous three-dimensional hydrogen-bonded networks. In the case of tetraurea 5e, 66% of the volume of the crystals is accessible to guests, and guests can be exchanged in single crystals without loss of crystallinity. Of special note are: (i) the use of tetrakis(4-isocyanatophenyl)methane (1f) as a precursor for making enantiomerically pure tetraurethanes and tetraureas, including compounds 5b, 5c; and (ii) their subsequent crystallization to give porous chiral hydrogen-bonded networks. Such materials promise to include chiral guests enantioselectively and to be useful in the separation of racemates, asymmetric catalysis, and other applications.Key words: crystal engineering, molecular tectonics, hydrogen bonding, networks, porosity, urethanes, ureas, tetraphenylmethane, tetraphenylsilane.


1992 ◽  
Vol 70 (1) ◽  
pp. 254-271 ◽  
Author(s):  
Ulrike Spohr ◽  
Eugenia Paszkiewicz-Hnatiw ◽  
Naohiko Morishima ◽  
Raymond U. Lemieux

The relative potencies of a wide variety of deoxygenated derivatives of the methyl glycoside of α-L-Fuc-(1 → 2)-β-D-Gal-(1 → 4)- β-D-GlcNAc (the H-type 2 human blood group related trisaccharide) for the inhibition of the binding of an artificial H-type 2 antigen by the lectin I of Ulexeuropaeus confirmed the previous evidence that the key and productive interaction involves only the three hydroxyl groups of the α-L-fucose unit, the hydroxyl at the 3-position of the β-D-galactose residue, and the nonpolar groups in their immediate environment. Except for the acetamido group and the hydroxymethyl of the β-D-Gal unit, which stay in the aqueous phase, on complex formation the remaining three hydroxyl groups appear to come to reside at or near the periphery of the combining site since their replacement by hydrogen causes relatively small changes (< ± 1 kcal/mol) in the stability of the complex (ΔG0). Relatively much larger but compensating changes occur for the enthalpy and entropy terms, and these may arise primarily from the differences in the water structure about the periphery of the combining site and the oligosaccharide both prior to and after complexation. It is proposed that steric constraints lead to an ordered state of the water molecules hydrogen-bonded to the polar groups within the cleft formed by the key region of the amphiphilic combining site. Their release to form less ordered clusters of more strongly hydrogen-bonded water molecules in bulk solution would contribute importantly to the driving force for complexation. It is demonstrated that the surface used for the binding of H-type 2-OMe by a monoclonal anti-H antibody is virtually identical to that used by the Ulex lectin. Keywords: molecular recognition, H-type 2 blood group determinant and deoxygenated derivatives, lectin I of Ulexeuropaeus, anti-H-type 2 monoclonal antibody, enthalpy–entropy compensation.


2003 ◽  
Vol 68 (2) ◽  
pp. 240-246 ◽  
Author(s):  
Hélène Sauriat-Dorizon ◽  
Thierry Maris ◽  
James D. Wuest ◽  
Gary D. Enright

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