Selective Effect of Guest Molecule Length and Hydrogen Bonding on the Supramolecular Host Structure

2005 ◽  
Vol 109 (47) ◽  
pp. 22296-22300 ◽  
Author(s):  
Dongxia Wu ◽  
Ke Deng ◽  
Qingdao Zeng ◽  
Chen Wang
Keyword(s):  
Hydrogen Bonding ◽  
Guest Molecule ◽  
Selective Effect ◽  
Host Structure

A thiourea-functionalized metal–organic macrocycle for the catalysis of Michael additions and prominent size-selective effect

2017 ◽  
Vol 46 (12) ◽  
pp. 4086-4092 ◽  
Author(s):  
Lu Yang ◽  
Liang Zhao ◽  
Zhen Zhou ◽  
Cheng He ◽  
Hui Sun ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Catalytic Performance ◽  
Size Selectivity ◽  
Selective Effect ◽  
Michael Additions ◽  
Metal Organic ◽  
Heterogeneous Phase

A discrete tetranuclear metal–organic macrocycle (MOM) containing thiourea groups as hydrogen bonding sites was prepared and exhibited a high catalytic performance in Michael additions of nitrostyrenes to nitroalkanes and size-selectivity in heterogeneous phase.

Managing Hydrogen Bonding in the Clathrate Hydrate of the 1-Pentanol Guest Molecule

CrystEngComm ◽  
2021 ◽  
Author(s):  
Byeonggwan Lee ◽  
Jeongtak Kim ◽  
Kyuchul Shin ◽  
Ki Hun Park ◽  
Minjun Cha ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Guest Molecule ◽  
Clathrate Hydrate ◽  
Guest Molecules

It remains a difficult task to predict the hydrate structure and conformation of potential guest molecules in one of the three canonical hydrate lattices. 1-pentanol is characteristic of molecules that...

scholarly journals Impact of the Confinement on the Intra-Cage Dynamics of Molecular Hydrogen in Clathrate Hydrates

2016 ◽  
Vol 879 ◽  
pp. 1294-1299
Author(s):  
Margarita Russina ◽  
Evout Kemner ◽  
Ferenc Mezei
Keyword(s):  
Time Scale ◽  
Guest Molecule ◽  
Ambient Pressure ◽  
Jump Diffusion ◽  
Clathrate Hydrates ◽  
Dynamic Heterogeneity ◽  
Temperature Dependent ◽  
Neutron Spectrometer ◽  
Hydrogen Molecules ◽  
Host Structure

We have studied the diffusive mobility of hydrogen molecules confined in different size cages in clathrate hydrates. In clathrate hydrate H2 molecules are effectively stored by confinement in two different size cages of the nanoporous host structure with accessible volumes of about 0.50 and 0.67 nm diameters, respectively. For the processes of sorption and desorption of the stored hydrogen the diffusive mobility of the molecules plays a fundamental role. In the present study we have focused on the dynamics of the H2 molecules inside the cages as one aspect of global guest molecule mobility across the crystalline host structure. We have found that for the two cage sizes different in diameter by only 34 % and in volume by about a factor of 2.4, the dimension can modify the diffusive mobility of confined hydrogen in both directions, i.e. reducing and surprisingly enhancing mobility compared to the bulk at the same temperature. In the smaller cages of clathrate hydrates hydrogen molecules are localized in the center of the cages even at temperatures >100 K. Confinement in the large cages leads to the onset already at T=10 K of jump diffusion between sorption sites separated from each other by about 2.9 Å at the 4 corners of a tetrahedron. At this temperature bulk hydrogen is frozen at ambient pressure and shows no molecular mobility on the same time scale. A particular feature of this diffusive mobility is the pronounced dynamic heterogeneity: only a temperature dependent fraction of the H2 molecules was found mobile on the time scale covered by the neutron spectrometer used. The differences in microscopic dynamics inside the cages of two different sizes can help to explain the differences in the parameters of macroscopic mobility: trapping of hydrogen molecules in smaller pores matching the molecule size can to play a role in the higher desorption temperature for the small cages.

Clathrates of tetracyanonickelates containing 1,4-dioxane

1987 ◽  
Vol 52 (12) ◽  
pp. 2890-2899 ◽  
Author(s):  
Mária Reháková ◽  
Anna Sopková
Keyword(s):  
Guest Molecule ◽  
Solid Product ◽  
Gc Analysis ◽  
Preparation Conditions ◽  
Direct Addition ◽  
Similar Product ◽  
Host Structure ◽  
Tetracyano Complexes

It was found after study of modifications of tetracyano complexes with 1,4-dioxane that a similar product is formed also by direct addition of 1,4-dioxane to a solution of [Ni(NH3)m][Ni(CN)4] or to solid NiNi(CN)4.nH2O; and 1,4-dioxane is initially bonded as a guest molecule and then as a ligand. The amount of guest component or ligand in the compounds Ni(NH3)m(C4H8O2)aNi(CN)4.(y-a)C4H8O2.nH2O and Ni(C4H8O2)aNi(CN)4.(n-a)C4H8O2 depends on the preparation conditions and on the conditions of storage of the solid product after isolation. The results of TA, IR, and GC analysis confirmed the presence of 1,4-dioxane bonded as a guest component and also 1,4-dioxane entering the host structure as a ligand.

scholarly journals Crystal structure of bis(pyridine-4-carbothioamide-κN1)bis(thiocyanato-κN)cobalt(II) methanol monosolvate

2017 ◽  
Vol 73 (11) ◽  
pp. 1786-1789 ◽  
Author(s):  
Tristan Neumann ◽  
Inke Jess ◽  
Christian Näther
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Title Compound ◽  
Three Dimensional ◽  
Methanol Molecule ◽  
Asymmetric Unit ◽  
Dimensional Network ◽  
Distorted Octahedral ◽  
Host Structure

The asymmetric unit of the title compound, [Co(NCS)2(C6H6NS)4]·CH3OH, consists of one cobalt(II) cation, two thiocyanate anions, four pyridine-4-carbothioamide ligands and one methanol molecule that are located in general positions. The CoIIcations are coordinated by two terminal N-bonding thiocyanate anions and four N-bonding pyridine-4-carbothioamide ligands, resulting in discrete and slightly distorted octahedral complexes. These complexes are linked into a three-dimensional networkviaintermolecular N—H...S hydrogen bonding between the amino H atoms and the thiocyanate and pyridine-4-carbothioamide S atoms. From this arrangement, channels are formed in which the methanol solvate molecules are embedded and linked to the host structure by intermolecular O—H...S and N—H...O hydrogen bonding.

scholarly journals Formation of quinol co-crystals with hydrogen-bond acceptors

2005 ◽  
Vol 61 (1) ◽  
pp. 46-57 ◽  
Author(s):  
Iain D. H. Oswald ◽  
W. D. Samuel Motherwell ◽  
Simon Parsons
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Crystal Structures ◽  
Guest Molecule ◽  
Crystal Packing ◽  
Strong Hydrogen Bond ◽  
Hydrogen Bond Acceptor ◽  
Guest Molecules ◽  
Sterically Hindered

The crystal structures of eight new co-crystals of quinol with pyrazine, piperazine, morpholine, pyridine, piperidine, 4,4′-bipyridine, N-methylmorpholine and N,N′-dimethylpiperazine are reported. Quinol forms 1:1 co-crystals with pyrazine, piperazine and N,N′-dimethylpiperazine, but 1:2 co-crystals with morpholine, 4,4′-bipyridine, N-methylmorpholine, pyridine and piperidine. This difference can be rationalized in most cases by the presence of, respectively, two or one strong hydrogen-bond acceptor(s) in the guest molecule. The exception to this generalization is 4,4′-bipyridine, which forms a 1:2 co-crystal, possibly to optimize crystal packing. All structures are dominated by hydrogen bonding between quinol and the guest molecules. A doubly bridging motif, which connects pairs of quinol and guest molecules via NH...O or CH...O interactions, is present in all but the sterically hindered N,N′-dimethylpiperazine and N-methylmorpholine co-crystals.

scholarly journals Vibrational Spectroscopic Analyses of (en)2-Td-type Clathrates

2020 ◽  
pp. 37-47
Author(s):  
G. Indramahalakshmi
Keyword(s):  
Hydrogen Bonding ◽  
Guest Molecule ◽  
Host Lattice ◽  
Relative Strength ◽  
Spectroscopic Analyses ◽  
Bonding Interaction ◽  
Bending Mode ◽  
Out Of Plane ◽  
Host Lattices ◽  
Ft Raman

The clathrates of Hofmann-(en)2-Td-type, M(en)2M’(CN)4.Aniline (M=Cu,Cd; M’=Cd,Zn) and their hosts were synthesized with the confirmation using FTIR spectra. Hydrogen bonding interaction between π-cloud of phenyl ring of the guest molecule and ethylenediamine(en) of the host lattices was deduced from the upward shift in ν(CH)out of plane bending mode of aniline. A second type of hydrogen bonding between C≡N group of the host lattice and NH2 of aniline guest was also inferred from the downward shift in ν(C≡N) of the clathrates. The relative strength of H-bonding in the clathrates was found to be Hofmann-(en)2-Type > Hofmann-(en)2-Td-Phenol > Hofmann-(en)2-Td-Aniline. The presence of major peaks corresponding to various modes of guest aniline, ligand en and cyanide group in FT Raman spectra also confirms the formation of clathrates. Attempts to synthesize Ni(en)2M’(CN)4.Aniline (M’=Cd,Zn) resulted in the formation of M’(en)2Ni(CN)4.2Aniline (M’=Cd,Zn) due to the exchange of metal ions and greater stability of Ni(CN)4 unit.

scholarly journals Crystal structures of tetrakis(pyridine-4-thioamide-κN)bis(thiocyanato-κN)cobalt(II) monohydrate and bis(pyridine-4-thioamide-κN)bis(thiocyanato-κN)zinc(II)

2018 ◽  
Vol 74 (2) ◽  
pp. 141-146 ◽  
Author(s):  
Tristan Neumann ◽  
Inke Jess ◽  
Christian Näther
Keyword(s):  
Hydrogen Bonding ◽  
Water Molecule ◽  
Crystal Structures ◽  
Rotation Axis ◽  
Three Dimensional ◽  
Water Molecules ◽  
Asymmetric Unit ◽  
Dimensional Network ◽  
Distorted Octahedral ◽  
Host Structure

Reaction of Co(NCS)2 and Zn(NCS)2 with 4-pyridinethioamide led to the formation of compounds with composition [Co(NCS)2(C6H6N2S)4]·H2O (1) and [Zn(NCS)2(C6H6N2S)2] (2), respectively. The asymmetric unit of compound 1, consists of one cobalt(II) cation, two thiocyanate anions, four 4-pyridinethioamide ligands and one water molecule whereas that of compound 2 comprises one zinc(II) cation that is located on a twofold rotation axis as well as one thiocyanate anion and one 4-pyridinethioamide ligand in general positions. In the structure of compound 1, the cobalt(II) cations are octahedrally coordinated by two terminal N-bonding thiocyanate anions and by the N atoms of four 4-pyridinethioamide ligands, resulting in discrete and slightly distorted octahedral complexes. These complexes are linked into a three-dimensional network via intermolecular N—H...S hydrogen bonding between the amino H atoms and the thiocyanate S atoms. From this arrangement, channels are formed in which the water molecules are embedded and linked to the host structure by intermolecular O—H...S and N—H...O hydrogen bonding. In the structure of compound 2, the zinc(II) cations are tetrahedrally coordinated by two N-bonding thiocyanate anions and the N atoms of two 4-pyridinethioamide ligands into discrete complexes. These complexes are likewise connected into a three-dimensional network by intermolecular N—H...S hydrogen bonding between the amino H atoms and the thioamide S atoms.

Hydrogen bonding in liquid methanol at ambient conditions and at high pressure

2000 ◽  
Vol 98 (3) ◽  
pp. 125-134 ◽  
Author(s):  
T. Weitkamp, J. Neuefeind, H. E. Fisch
Keyword(s):  
High Pressure ◽  
Hydrogen Bonding ◽  
Ambient Conditions
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