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Hydrogen-bonded Supramolecular Structures (hydrogen-bonded + supramolecular_structure)

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Chemistry100%

Selected Abstracts

trans -Diaquabis(nicotinamide-,N)bis(salicylato-,O)cobalt(II)

ACTA CRYSTALLOGRAPHICA SECTION C, Issue 10 2008

The title compound, [Co(C7H5O3)2(C6H6N2O)2(H2O)2], forms a three-dimensional hydrogen-bonded supramolecular structure. The CoII ion is in an octahedral coordination environment comprising two pyridyl N atoms, two carboxylate O atoms and two O atoms from water molecules. Intermolecular N,H...O and O,H...O hydrogen bonds produce R22(8), R22(12) and R22(14) rings, which lead to two-dimensional chains. An extensive three-dimensional supramolecular network of C,H...O, N,H...O and O,H...O hydrogen bonds and C,H..., interactions is responsible for crystal structure stabilization. This study is an example of the construction of a supramolecular assembly based on hydrogen bonds in mixed-ligand metal complexes. [source]

Multirotations of (Anilinium)([18]Crown-6) Supramolecular Cation Structure in Magnetic Salt of [Ni(dmit)2],

CHEMISTRY - AN ASIAN JOURNAL, Issue 9 2007
Sadafumi Nishihara Dr.
Abstract A solid-state dynamic supramolecular structure consisting of (anilinium)([18]crown-6) was arranged as the cation in a salt of [Ni(dmit)2], (dmit=2-thioxo-1,3-dithiole-4,5-dithiolate). With the ammonium moiety of anilinium located within the cavity of [18]crown-6, a hydrogen-bonded supramolecular structure is formed, with an orthogonal arrangement between the ,,plane of anilinium and the mean O6 plane of [18]crown-6. In this supramolecular cation, both anilinium and [18]crown-6 act as dynamic units with different rotational modes in the solid state. The uniform stacks of cations form an antiparallel arrangement, thus producing a layer structure. Sufficient space for the 180° flip-flop motion of the phenyl ring and the rotation of [18]crown-6 was observed in the cation layer. Thermally activated 180° flip-flop motions, with a frequency of 6,MHz at room temperature and an activation energy of 31,kJ,mol,1, were confirmed by temperature-dependent 2H,NMR spectra of ([D5]anilinium)-([18]crown-6)[Ni(dmit)2]. A double-minimum potential for the molecular rotation of anilinium, with a barrier of approximately 40,kJ,mol,1, was indicated by ab,initio calculations. The wide-line 1H,NMR spectra indicated a thermally activated rotation of [18]crown-6 at temperatures above 250,K. Therefore, multiple molecular motions of the 180° flip-flop motion of the phenyl ring and the rotation of [18]crown-6 occur simultaneously in the solid state. The temperature-dependent dielectric constants revealed that the molecular motion of [18]crown-6, other than the flip-flop motion, dominates the dielectric response in the measured temperature and frequency range. [source]

Three isomeric 1-(2-chloronicotinoyl)-2-(nitro­phenyl)hydrazines, including three polymorphs of 1-(2-chloronicotinoyl)-2-(2-nitrophenyl)hydrazine: hydrogen-bonded supramolecular structures in two and three dimensions

ACTA CRYSTALLOGRAPHICA SECTION B, Issue 1 2007
Solange M. S. V. Wardell
1-(2-Chloronicotinoyl)-2-(2-nitrophenyl)hydrazine, C12H9Cl­N4O3, crystallizes in three polymorphic forms, two monoclinic forms in space groups Cc (Ia) and P21 (Ib), and an orthorhombic form in space group Pbcn (Ic). In the Cc polymorph (Ia) the molecules are linked into sheets by combinations of one N,H,O and two C,H,O hydrogen bonds, while in the P21 polymorph (Ib) the molecules are linked into sheets by combinations of three hydrogen bonds, one each of N,H,O, C,H,N and C,H,O types. In the orthorhombic polymorph (Ic) the molecules are linked into a complex three-dimensional framework structure by a combination of one N,H,O, one N,H,N and three C,H,O hydrogen bonds, and an aromatic ,,, stacking interaction. In the isomeric compound 1-(2-chloronicotinoyl)-2-(3-nitrophenyl)hydrazine (II) the molecules are again linked into a three-dimensional framework, this time by a combination of three hydrogen bonds, one each of N,H,O, N,H,N and C,H,O types, weakly augmented by a ,,, stacking interaction. The molecules of 1-(2-chloronicotinoyl)-2-(4-nitrophenyl)hydrazine (III) are linked into sheets by a combination of three hydrogen bonds, one each of N,H,O, N,H,N and C,H,O types. [source]

Hydrated salts of 3,5-dihydroxybenzoic acid with organic diamines: hydrogen-bonded supramolecular structures in two and three dimensions

ACTA CRYSTALLOGRAPHICA SECTION B, Issue 3 2001
Colin J. Burchell
The trigonally trisubstituted acid 3,5-dihydroxybenzoic acid forms hydrated salt-type adducts with organic diamines. In 1,4-diazabicyclo[2.2.2]octane,3,5-dihydroxybenzoic acid,water (1/1/1) (1), where Z, = 2 in P21/c, the constitution is [HN(CH2CH2)3N]+·[(HO)2C6H3COO],·H2O: the anions and the water molecules are linked by six O,H,O hydrogen bonds to form two-dimensional sheets and each cation is linked to a single sheet by one O,H,N and one N,H,O hydrogen bond. Piperazine,3,5-dihydroxybenzoic acid,water (1/2/4) (2) and 1,2-diaminoethane,3,5-dihydroxybenzoic acid,water (1/2/2) (3) are also both salts with constitutions [H2N(CH2CH2)2NH2]2+·2[(HO)2C6H3COO],·4H2O and [H3NCH2CH2NH3]2+·2[(HO)2C6H3COO],·2H2O, respectively. Both (2) and (3) have supramolecular structures which are three-dimensional: in (2) the anions and the water molecules are linked by six O,H,O hydrogen bonds to form a three-dimensional framework enclosing large centrosymmetric voids, which contain the cations that are linked to the framework by two N,H,O hydrogen bonds; in (3) the construction of the three-dimensional framework requires the participation of cations, anions and water molecules, which are linked together by four O,H,O and three N,H,O hydrogen bonds. [source]

Two N,N,-diaryl-2,2,2-trichloroethane-1,1-diamines: hydrogen-bonded supramolecular structures in one and two dimensions

ACTA CRYSTALLOGRAPHICA SECTION C, Issue 9 2007
Zhen-Feng Zhang
The molecules of 2,2,2-trichloro- N,N,-diphenylethane-1,1-diamine, C14H13Cl3N2, are linked into (040) sheets by a combination of C,H...Cl and C,H...,(arene) hydrogen bonds. In 2,2,2-trichloro- N,N,-bis(4-methylphenyl)ethane-1,1-diamine, C16H17Cl3N2, the molecules are linked into C(7) chains by two independent C,H...Cl hydrogen bonds and one Cl...Cl contact. [source]