Inclusion complexes of a new host, 4,5-bis(4-methoxyphenyl)-2-(4-nitrophenyl)-1H-imidazole, with various guests

Sakaino, Yoshiko; Fujii, R.; Fujiwara, T.

doi:10.1039/p19900002852

Cited by 20 publications

(18 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As the largest void in this phase is located on an inversion centre and our simulations require residues in general positions, all solvate models were deduced for the non-centrosymmetric subgroup P1 rather than for P1 . A 40 3 void, such as that in b-1, is clearly too small to accommodate any organic solvent molecule. CSD data (refcodes HEXANE and HEXANE01) indicate that a molecule of n-hexane occupies a volume of 160 3 .…”

Section: Resultsmentioning

confidence: 99%

“…Among these, design and control of molecular packing in crystals ("crystal engineering") continues to attract growing attention, since in this way basic properties of solid molecular materials can be modified. [1][2][3] Such options are especially important for electronic materials and for compounds with catalytic or physiological activity. To give just two examples, the electron mobility of a given molecular crystal significantly depends on packing, and the bio-availability of a solid drug can vary considerably from one polymorphic modification to the other.…”

Section: Introductionmentioning

confidence: 99%

“…A 40 3 void, such as that in b-1, is clearly too small to accommodate any organic solvent molecule. CSD data (refcodes HEXANE and HEXANE01) indicate that a molecule of n-hexane occupies a volume of 160 3 .…”

mentioning

confidence: 99%

“…361 (3) models were deduced for the non-centrosymmetric subgroup P1 rather than for P1 . A 40 3 void, such as that in b-1, is clearly too small to accommodate any organic solvent molecule.…”

mentioning

confidence: 99%

See 3 more Smart Citations

Conformational Dimorphism of 1,1,3,3,5,5‐Hexachloro‐1,3,5‐trigermacyclohexane: Solvent‐Induced Crystallization of a Metastable Polymorph Containing Boat‐Shaped Molecules

Ischenko

Englert

Jansen

2005

Chemistry A European J

View full text Add to dashboard Cite

Two crystalline modifications of 1,1,3,3,5,5-hexachloro-1,3,5-trigermacyclohexane have been experimentally obtained as phase pure products and studied by single-crystal X-ray diffraction. The six-membered heterocycles adopt a chair conformation in the alpha-phase; this polymorph is accessible by crystallisation from solution and from the melt. In contrast, the beta-form is built up from boat-shaped molecules; it can exclusively be crystallised from n-hexane. At the molecular level, formation energies of the 1,1,3,3,5,5-hexachloro-1,3,5-trigermacyclohexane conformers have been compared by using molecular mechanics, semiempirical and ab-initio quantum mechanical calculations. Possible reasons for the selective formation of the alpha- or beta-phase in specific solvents have been considered. Formation of the metastable phase is suggested to occur via a hypothetical intermediate of composition [(GeCl2CH2)3].0.5C6H14. For such an in-silico solvate, a crystal structure of favourable lattice energy, closely related to the experimentally observed beta-modification, has been found through global energy minimisation. Elimination of the n-hexane molecules from this computer-generated solid and subsequent simulated annealing resulted in a crystal structure that corresponds to the experimentally observed beta-phase within the limits of the force field calculations. This scenario implies solvent directed crystallisation of a metastable polymorphic molecular crystal.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

See 2 more Smart Citations

Conformational Dimorphism of 1,1,3,3,5,5‐Hexachloro‐1,3,5‐trigermacyclohexane: Solvent‐Induced Crystallization of a Metastable Polymorph Containing Boat‐Shaped Molecules

Ischenko

Englert

Jansen

2005

Chemistry A European J

View full text Add to dashboard Cite

show abstract

“…Although polymorphism, the ability of a substance to exist in more than one crystalline form, is fundamental to solid-state chemistry [1][2][3][4] and is important for the elucidation of a relationship between structure and property of crystals [5][6][7][8][9][10][11][12][13], meta-stable polymorphs are generally difficult to form by recrystallization [4]. Structure-property relationship can also be studied using solvates [14][15][16][17]. A material sometimes crystallizes in a different solvation state [18,19].…”

Section: Introductionmentioning

confidence: 99%

Solvent effects on the crystal photochromism of 4,4′-methylenebis{(N-3,5-di-tert-butylsalicylidene)-2,6-dimethylaniline}

2009

View full text Add to dashboard Cite

4,4 0 -methylenebis{N-(3,5-di-tert-butylsalicylidene)-2,6-dimethylaniline} formed a definite acetone-inclusion crystal by recrystallization with acetone. Through crystal-to-crystal solvent exchange of the crystal, various types of crystals were obtained. All resulting crystals exhibited photochromism. Rate constants of thermal fading of photochromes were found to depend on the number of solvent molecules included in the crystal unit. The thermal stability of photochrome is discussed in connection with molecular mobility in the crystal lattice.

show abstract

Novel 4-Vinylpyridine-Extended Metal-Dibenzoylmethanate Host Frameworks: Structure, Polymorphism, and Inclusion Properties

Soldatov

Ripmeester

2001

Chem. Eur. J.

View full text Add to dashboard Cite

In this contribution we show that host materials based on metal dibenzoylmethanates (DBM) can be extended in a versatile way by decreasing the packing efficiency of the simpler metal DBM's reported earlier. Specifically, this can be accomplished by coordinating two 4-vinylpyridines (4-ViPy) to the metal (Ni or Co) DBM units to give [M(4-ViPy)2(DBM)2] host complexes. These display a remarkable polymorphism and an ability to form inclusion compounds with a large variety of organic species. Five non-clathrate phases representing three polymorphic types and twenty-eight inclusion compounds with nineteen guests, representing five structural types were isolated and studied in varying degrees of detail. The inclusion compounds can be prepared by recrystallization or by interaction of the solid host with guest vapor. In the latter case, the process realization, kinetics and final product strongly depend on the host polymorph chosen as starting material. Kinetic studies executed with powder XRD suggest that transient formation of inclusion compounds may occur even during solvent vapor induced transformation of one guest-free polymorph to another. The beta polymorph of the Ni-host reveals the strongest clathratogenic ability as well as a high selectivity towards certain homologues and isomers. Its properties give insight into the concept of "flexible zeolite mimics", or "apohosts", as this empty host form is energetically and structurally predisposed towards inclusion processes. In all eleven (three host and eight clathrate) structures studied by single crystal X-ray diffraction the [M(4-Vi-Py)2(DBM)2] complex molecule is transconfigured. In most, the host molecules show effective packing in one dimension by forming parallel chains. Guest species are located between the chains in cages or channels formed by combining voids in the host molecules belonging to adjacent chains. The corresponding Ni and Co versions of the compounds studied were similar.

show abstract

Inclusion complexes of a new host, 4,5-bis(4-methoxyphenyl)-2-(4-nitrophenyl)-1H-imidazole, with various guests

Cited by 20 publications

References 0 publications

Conformational Dimorphism of 1,1,3,3,5,5‐Hexachloro‐1,3,5‐trigermacyclohexane: Solvent‐Induced Crystallization of a Metastable Polymorph Containing Boat‐Shaped Molecules

Conformational Dimorphism of 1,1,3,3,5,5‐Hexachloro‐1,3,5‐trigermacyclohexane: Solvent‐Induced Crystallization of a Metastable Polymorph Containing Boat‐Shaped Molecules

Solvent effects on the crystal photochromism of 4,4′-methylenebis{(N-3,5-di-tert-butylsalicylidene)-2,6-dimethylaniline}

Novel 4-Vinylpyridine-Extended Metal-Dibenzoylmethanate Host Frameworks: Structure, Polymorphism, and Inclusion Properties

Contact Info

Product

Resources

About