14 research outputs found
Dynamic Aspects of Lattice Inclusion Complexation Involving a Phase Change. Equilibrium, Kinetics, and Energetics of Guest-Binding to a Hydrogen-Bonded Flexible Organic Network
The solid/gas complexation of anthracenebisresorcinol host (1) and ethyl acetate as a guest was
monitored by pressure-decay, X-ray powder diffraction, and gravimetric/calorimetric thermal desorption analyses.
It involves an exothermic (∼30 kcal/mol) phase transition and exhibits “vertical” adsorption as well as desorption
“isotherms” at a threshold (equilibrium) pressure (Pth) of the guest vapor. This is in accord with the phase
rule for a two-component/three-phase/one-freedom system. The activation energies of adsorption and desorption
are 2.3 and 34 kcal/mol, respectively; desorption at 25 °C takes weeks. The crystal structure of the ethyl
acetate adduct illustrates how the flexible hydrogen-bonded network of host 1 adjusts itself to the small guest.
Other polar guests (ester, ketone, and alcohol) behave similarly and give rise to desorption-resistant stable
adducts, except for the least bulky members of the ester and ketone guests, i.e., methyl acetate and acetone.
The mechanism of phase transition is discussed in light of the lack of size effect as for the host and well-behaved guest-prebinding at P Pth
Helical Coordination Polymers from Achiral Components in Crystals. Homochiral Crystallization, Homochiral Helix Winding in the Solid State, and Chirality Control by Seeding
An achiral anthracene−pyrimidine derivative (5-(9-anthracenyl)pyrimidine, 1) forms adduct 1·Cd(NO3)2·H2O·EtOH (2) in chiral space group P21. The metal ion is hexacoordinated with two pyrimidine ligands
(equatorial cis), water and ethanol (equatorial cis), and two nitrate ions (axial trans). The chirality arises from
a pyrimidine−Cd2+ helical array and is preserved not only in each crystal via homochiral interstrand water−nitrate hydrogen bonding but also in all the crystals in the same chirality as a result of single-colony homochiral
crystal growth. Compound 1 also forms achiral (Pbca) trihydrate adduct 1·Cd(NO3)2·3H2O (3) having nonhelical
pyrimidine−Cd2+ zigzag chains. Achiral zigzag polymer 3 and chiral helical polymer 2 are interconvertible
with each other in the solid states upon exchange of volatile ligands (ethanol and water). The helix winding
associated with the conversion of adduct 3 to 2 can be made homochiral by seeding
Dynamic Aspects of Lattice Inclusion Complexation Involving a Phase Change. Equilibrium, Kinetics, and Energetics of Guest-Binding to a Hydrogen-Bonded Flexible Organic Network
The solid/gas complexation of anthracenebisresorcinol host (1) and ethyl acetate as a guest was
monitored by pressure-decay, X-ray powder diffraction, and gravimetric/calorimetric thermal desorption analyses.
It involves an exothermic (∼30 kcal/mol) phase transition and exhibits “vertical” adsorption as well as desorption
“isotherms” at a threshold (equilibrium) pressure (Pth) of the guest vapor. This is in accord with the phase
rule for a two-component/three-phase/one-freedom system. The activation energies of adsorption and desorption
are 2.3 and 34 kcal/mol, respectively; desorption at 25 °C takes weeks. The crystal structure of the ethyl
acetate adduct illustrates how the flexible hydrogen-bonded network of host 1 adjusts itself to the small guest.
Other polar guests (ester, ketone, and alcohol) behave similarly and give rise to desorption-resistant stable
adducts, except for the least bulky members of the ester and ketone guests, i.e., methyl acetate and acetone.
The mechanism of phase transition is discussed in light of the lack of size effect as for the host and well-behaved guest-prebinding at P Pth
Dynamic Aspects of Lattice Inclusion Complexation Involving a Phase Change. Equilibrium, Kinetics, and Energetics of Guest-Binding to a Hydrogen-Bonded Flexible Organic Network
The solid/gas complexation of anthracenebisresorcinol host (1) and ethyl acetate as a guest was
monitored by pressure-decay, X-ray powder diffraction, and gravimetric/calorimetric thermal desorption analyses.
It involves an exothermic (∼30 kcal/mol) phase transition and exhibits “vertical” adsorption as well as desorption
“isotherms” at a threshold (equilibrium) pressure (Pth) of the guest vapor. This is in accord with the phase
rule for a two-component/three-phase/one-freedom system. The activation energies of adsorption and desorption
are 2.3 and 34 kcal/mol, respectively; desorption at 25 °C takes weeks. The crystal structure of the ethyl
acetate adduct illustrates how the flexible hydrogen-bonded network of host 1 adjusts itself to the small guest.
Other polar guests (ester, ketone, and alcohol) behave similarly and give rise to desorption-resistant stable
adducts, except for the least bulky members of the ester and ketone guests, i.e., methyl acetate and acetone.
The mechanism of phase transition is discussed in light of the lack of size effect as for the host and well-behaved guest-prebinding at P Pth
Dynamic Aspects of Lattice Inclusion Complexation Involving a Phase Change. Equilibrium, Kinetics, and Energetics of Guest-Binding to a Hydrogen-Bonded Flexible Organic Network
The solid/gas complexation of anthracenebisresorcinol host (1) and ethyl acetate as a guest was
monitored by pressure-decay, X-ray powder diffraction, and gravimetric/calorimetric thermal desorption analyses.
It involves an exothermic (∼30 kcal/mol) phase transition and exhibits “vertical” adsorption as well as desorption
“isotherms” at a threshold (equilibrium) pressure (Pth) of the guest vapor. This is in accord with the phase
rule for a two-component/three-phase/one-freedom system. The activation energies of adsorption and desorption
are 2.3 and 34 kcal/mol, respectively; desorption at 25 °C takes weeks. The crystal structure of the ethyl
acetate adduct illustrates how the flexible hydrogen-bonded network of host 1 adjusts itself to the small guest.
Other polar guests (ester, ketone, and alcohol) behave similarly and give rise to desorption-resistant stable
adducts, except for the least bulky members of the ester and ketone guests, i.e., methyl acetate and acetone.
The mechanism of phase transition is discussed in light of the lack of size effect as for the host and well-behaved guest-prebinding at P Pth
Functional Self-Assembly of Hydrogen-Bonded Networks. Construction of Aromatic Stacks and Columns and Cavity-Size Control via Flexible Intercalation of 1D Chains Having Orthogonal Aromatic Substituents
Anthracene−monoresorcinol derivative 1 forms
hydrogen-bonded poly(resorcinol) 1D chains, which
self-assemble via interpenetration or intercalation of the orthogonal
anthracene (A) substituents. Guest-binding in
the
resulting cavities leads to either, depending on the guests (G,
aromatic or aliphatic), an alternate
···A·G·A·G···
(monomeric) or an ···A·A·G·G···
(dimeric) lattice pattern. The monomeric lattices show
a remarkable linear-alkyl
vs branched-alkyl selectivity in the guest-binding. The dimeric
lattices are characterized by their exclusive emission
of excimer fluorescence. Self-assembly of the present 1D chains is
thus functional and also flexible and dynamic;
removal, addition, and exchange of guest molecules readily occur in the
solid states
Functional Self-Assembly of Hydrogen-Bonded Networks. Construction of Aromatic Stacks and Columns and Cavity-Size Control via Flexible Intercalation of 1D Chains Having Orthogonal Aromatic Substituents
Anthracene−monoresorcinol derivative 1 forms
hydrogen-bonded poly(resorcinol) 1D chains, which
self-assemble via interpenetration or intercalation of the orthogonal
anthracene (A) substituents. Guest-binding in
the
resulting cavities leads to either, depending on the guests (G,
aromatic or aliphatic), an alternate
···A·G·A·G···
(monomeric) or an ···A·A·G·G···
(dimeric) lattice pattern. The monomeric lattices show
a remarkable linear-alkyl
vs branched-alkyl selectivity in the guest-binding. The dimeric
lattices are characterized by their exclusive emission
of excimer fluorescence. Self-assembly of the present 1D chains is
thus functional and also flexible and dynamic;
removal, addition, and exchange of guest molecules readily occur in the
solid states
Functional Self-Assembly of Hydrogen-Bonded Networks. Construction of Aromatic Stacks and Columns and Cavity-Size Control via Flexible Intercalation of 1D Chains Having Orthogonal Aromatic Substituents
Anthracene−monoresorcinol derivative 1 forms
hydrogen-bonded poly(resorcinol) 1D chains, which
self-assemble via interpenetration or intercalation of the orthogonal
anthracene (A) substituents. Guest-binding in
the
resulting cavities leads to either, depending on the guests (G,
aromatic or aliphatic), an alternate
···A·G·A·G···
(monomeric) or an ···A·A·G·G···
(dimeric) lattice pattern. The monomeric lattices show
a remarkable linear-alkyl
vs branched-alkyl selectivity in the guest-binding. The dimeric
lattices are characterized by their exclusive emission
of excimer fluorescence. Self-assembly of the present 1D chains is
thus functional and also flexible and dynamic;
removal, addition, and exchange of guest molecules readily occur in the
solid states
Functional Self-Assembly of Hydrogen-Bonded Networks. Construction of Aromatic Stacks and Columns and Cavity-Size Control via Flexible Intercalation of 1D Chains Having Orthogonal Aromatic Substituents
Anthracene−monoresorcinol derivative 1 forms
hydrogen-bonded poly(resorcinol) 1D chains, which
self-assemble via interpenetration or intercalation of the orthogonal
anthracene (A) substituents. Guest-binding in
the
resulting cavities leads to either, depending on the guests (G,
aromatic or aliphatic), an alternate
···A·G·A·G···
(monomeric) or an ···A·A·G·G···
(dimeric) lattice pattern. The monomeric lattices show
a remarkable linear-alkyl
vs branched-alkyl selectivity in the guest-binding. The dimeric
lattices are characterized by their exclusive emission
of excimer fluorescence. Self-assembly of the present 1D chains is
thus functional and also flexible and dynamic;
removal, addition, and exchange of guest molecules readily occur in the
solid states
Functional Self-Assembly of Hydrogen-Bonded Networks. Construction of Aromatic Stacks and Columns and Cavity-Size Control via Flexible Intercalation of 1D Chains Having Orthogonal Aromatic Substituents
Anthracene−monoresorcinol derivative 1 forms
hydrogen-bonded poly(resorcinol) 1D chains, which
self-assemble via interpenetration or intercalation of the orthogonal
anthracene (A) substituents. Guest-binding in
the
resulting cavities leads to either, depending on the guests (G,
aromatic or aliphatic), an alternate
···A·G·A·G···
(monomeric) or an ···A·A·G·G···
(dimeric) lattice pattern. The monomeric lattices show
a remarkable linear-alkyl
vs branched-alkyl selectivity in the guest-binding. The dimeric
lattices are characterized by their exclusive emission
of excimer fluorescence. Self-assembly of the present 1D chains is
thus functional and also flexible and dynamic;
removal, addition, and exchange of guest molecules readily occur in the
solid states
