Home  About us  Contact
 

Two-dimensional Nets (two-dimensional + net)

Distribution by Scientific Domains
Chemistry100%

Selected Abstracts

Graphene-like nets of hydrogen-bonded water molecules in the dihydrate of 2-[(2-ammonioethyl)amino]acetate and the structure of its anhydrous hydroiodide salt

ACTA CRYSTALLOGRAPHICA SECTION C, Issue 8 2010
Tove Wiklund
2-[(2-Ammonioethyl)amino]acetate dihydrate, better known as N -(2-aminoethyl)glycine dihydrate, C4H10N2O2·2H2O, (I), crystallizes as a three-dimensional hydrogen-bonded network. Amino acid molecules form layers in the ac plane separated by layers of water molecules, which form a hydrogen-bonded two-dimensional net composed of fused six-membered rings having boat conformations. The crystal structure of the corresponding hydroiodide salt, namely 2-[(2-ammonioethyl)ammonio]acetate iodide, C4H11N2O2+·I,, (II), has also been determined. The structure of (II) does not accommodate any solvent water molecules, and displays stacks of amino acid molecules parallel to the a axis, with iodide ions located in channels, resulting in an overall three-dimensional hydrogen-bonded network structure. N -(2-Aminoethyl)glycine is a molecule of considerable biological interest, since its polyamide derivative forms the backbone in the DNA mimic peptide nucleic acid (PNA). [source]

Oligosiloxanediols as building blocks for supra­molecular chemistry: hydrogen-bonded adducts with amines form supramolecular structures in zero, one and two dimensions

ACTA CRYSTALLOGRAPHICA SECTION B, Issue 2 2000
Brian O'Leary
The structure of 1,1,3,3,5,5-hexaphenyltrisiloxane-1,5-diol,pyrazine (4/1), (C36H32O4Si3)4·C4H4N2 (1), contains finite centrosymmetric aggregates; the diol units form dimers, by means of O,H,O hydrogen bonds, and pairs of such dimers are linked to the pyrazine by means of O,H,N hydrogen bonds. In 1,1,3,3,5,5-hexaphenyltrisiloxane-1,5-diol,pyridine (2/3), (C36H32O4Si3)2·(C5H5N)3 (2), the diol units are linked into centrosymmetric pairs by means of disordered O,H,O hydrogen bonds: two of the three pyridine molecules are linked to the diol dimer by means of ordered O,H,N hydrogen bonds, while the third pyridine unit, which is disordered across a centre of inversion, links the diol dimers into a C33(9) chain by means of O,H,N and C,H,O hydrogen bonds. In 1,1,3,3-tetraphenyldisiloxane-1,3-diol,hexamethylenetetramine (1/1), (C24H22O3Si2)·C6H12N4 (3), the diol acts as a double donor and the hexamethylene­tetramine acts as a double acceptor in ordered O,H,N hydrogen bonds and the structure consists of C22(10) chains of alternating diol and amine units. In 1,1,3,3-tetraphenyldi­siloxane-1,3-diol,2,2,-bipyridyl (1/1), C24H22O3Si2·C10H8N2 (4), there are two independent diol molecules, both lying across centres of inversion and therefore both containing linear Si,O,Si groups: each diol acts as a double donor of hydrogen bonds and the unique 2,2,-bipyridyl molecule acts as a double acceptor, thus forming C22(11) chains of alternating diol and amine units. The structural motif in 1,1,3,3-tetra­phenyldisiloxane-1,3-diol,pyrazine (2/1), (C24H22O3Si2)2·C4H4N2 (5), is a chain-of-rings: pairs of diol molecules are linked by O,H,O hydrogen bonds into centrosymmetric R22(12) dimers and these dimers are linked into C22(13) chains by means of O,H,N hydrogen bonds to the pyrazine units. 1,1,3,3-Tetraphenyldisiloxane-1,3-diol,pyridine (1/1), C24H22O3Si2·C5H5N (6), and 1,1,3,3-tetraphenyldisiloxane-1,3-diol,pyrimidine (1/1), C24H22O3Si2·C4H4N2 (7), are isomorphous: in each compound the amine unit is disordered across a centre of inversion. The diol molecules form C(6) chains, by means of disordered O,H,O hydrogen bonds, and these chains are linked into two-dimensional nets built from R66(26) rings, by a combination of O,H,N and C,H,O hydrogen bonds. [source]

Cadmium(II) thio- and selenocyanate complexes of 3,3,-bis(1,2,4-triazol-4-yl)-1,1,-biadamantane, a ligand designed with an `extended nanodiamond' aliphatic platform

ACTA CRYSTALLOGRAPHICA SECTION C, Issue 7 2010
Ganna A. Senchyk
In the structures of the CdII pseudohalide coordination polymer poly[[diaquabis[,2 -3,3,-bis(1,2,4-triazol-4-yl)-1,1,-biadamantane-,2N1:N1,]cadmium(II)] dithiocyanate dihydrate], {[Cd(C24H32N6)2(H2O)2](NCS)2·2H2O}n, (I), and the isomorphous selenocyanate analogue, {[Cd(C24H32N6)2(H2O)2](NCSe)2·2H2O}n, (II), the CdII cations occupy inversion centres and have octahedral CdN4O2 environments, completed by four N atoms of the organic ligands [Cd,N = 2.316,(2) and 2.361,(2),Å for (I), and 2.313,(3) and 2.372,(3),Å for (II)] and two trans -coordinated aqua ligands [Cd,O = 2.3189,(15),Å for (I) and 2.323,(2),Å for (II)]. In each compound, the ligand displays a bidentate N1:N1, -bridging mode, connecting the metal centres at a distance of 14.66,Å into two-dimensional nets of (4,4)-topology, while the uncoordinated thio(seleno)cyanate anions reside inside the net cavities. Hydrogen bonding between the water molecules, anions and 1,2,4-triazole N atoms supports the tight packing, with an interlayer distance of 6.09,Å. [source]

catena -Poly[[[tetraaquazinc(II)]-,-4-amino-3,5-di-3-pyridyl-4H -1,2,4-triazole] sulfate monohydrate] and poly[[bis(,-4-amino-3,5-di-4-pyridyl-4H -1,2,4-triazole)diaquacopper(II)] dinitrate octahydrate]

ACTA CRYSTALLOGRAPHICA SECTION C, Issue 6 2009
Hai-Ying Wang
The isomeric bent triazole-containing ligands 4-amino-3,5-di-3-pyridyl-4H -1,2,4-triazole (L1) and 4-amino-3,5-di-4-pyridyl-4H -1,2,4-triazole (L2) have been used to create the two novel title complexes catena -poly[[[tetraaquazinc(II)]-,-4-amino-3,5-di-3-pyridyl-4H -1,2,4-triazole] sulfate monohydrate], {[Zn(C12H10N6)(H2O)4]SO4·H2O}n, (I), and poly[[diaquabis(,-4-amino-3,5-di-4-pyridyl-4H -1,2,4-triazole)copper(II)] dinitrate octahydrate], {[Cu(C12H10N6)2(H2O)2](NO3)2·8H2O}n, (II). The ZnII and CuII atoms are all six-coordinated in approximately octahedral environments. Compound (I) presents a sinusoidal chain generated by ZnO4 cores which are bridged by L1 ligands in a cisoid conformation. These sinusoidal chains are bound to each other by O,H...O hydrogen bonds between coordinated water molecules of neighboring chains into a two-dimensional network. These layers stack in an ,ABAB, sequence and are further linked into a three-dimensional framework through O,H...N hydrogen bonds between coordinated water molecules and the N atoms of the triazole rings. In (II), the CuII centers are bridged by the L2 ligands to form a two-dimensional network with square grids. All of the two-dimensional nets also stack alternately along the crystallographic a axis. Neighboring layers are further linked into a three-dimensional framework via interlayer N,H...N hydrogen bonds between ,NH2 groups of the triazole rings and the N atoms in the triazole rings. [source]

A novel two-dimensional framework based on unprecedented cadmium(II) chains

ACTA CRYSTALLOGRAPHICA SECTION C, Issue 2 2009
Jie Qin
The bent ligand 4-[(1H -1,2,4-triazol-1-yl)methyl]benzoic acid (HL) has been used to create the novel two-dimensional coordination polymer poly[,2 -aqua-,2 -chlorido-{,2 -4-[(1H -1,2,4-triazol-1-yl)methyl]benzoato}cadmium(II)], [Cd(C10H8N3O2)Cl(H2O)]n, under hydrothermal reaction of HL with cadmium chloride. The crystallographically unique Cd atom is seven-coordinated in an approximately pentagonal,bipyramidal environment of two carboxylate O atoms, two water O atoms, two Cl atoms and one triazole N atom. A notable feature is the presence of zigzag ...Cd...Cd... inorganic chains, in which neighboring CdII ions are doubly bridged by pairs of ,2 -Cl atoms and ,2 -H2O ligands in an alternating fashion. To the authors' knowledge, this is the first example containing this bridging mode in a cadmium(II) framework. The chains are connected to one another through the bridging L, ligand into a two-dimensional undulating network. All of the two-dimensional nets stack exactly together in an ,AA, stacking sequence along the crystallographic b axis. Neighboring layers are further linked into a three-dimensional framework via interlayer hydrogen-bonding interactions. [source]