Home  About us  Contact
 

Parallel Mode (parallel + mode)

Distribution by Scientific Domains
Chemistry100%

Selected Abstracts

A novel parallel interpenetrating two-dimensional (4,4) network: poly[[,2 -1,4-bis(imidazol-1-ylmethyl)benzene](,2 -naphthalene-1,4-dicarboxylato)zinc(II)]

ACTA CRYSTALLOGRAPHICA SECTION C, Issue 9 2009
Ya-Ping Li
In the title coordination compound, [Zn(C12H6O4)(C14H14N4)]n, the two ZnII centers exhibit different coordination environments. One ZnII center is four-coordinated in a distorted tetrahedral environment surrounded by two carboxylate O atoms from two different naphthalene-1,4-dicarboxylate (1,4-ndc) anions and two N atoms from two distinct 1,4-bis(imidazol-1-ylmethyl)benzene (1,4-bix) ligands. The coordination of the second ZnII center comprises two N atoms from two different 1,4-bix ligands and three carboxylate O atoms from two different 1,4-ndc ligands in a highly distorted square-pyramidal environment. The 1,4-bix ligand and the 1,4-ndc anion link adjacent ZnII centers into a two-dimensional four-connected (4,4) network. The two (4,4) networks are interpenetrated in a parallel mode. [source]

Poly[diaqua[,-1,4-bis(imidazol-1-ylmethyl)benzene-,2N3:N3,](,- trans -cyclohexane-1,4-carboxylato-,2O1:O4)manganese(II)]: a three-dimensional hydrogen-bonding ,-polonium net

ACTA CRYSTALLOGRAPHICA SECTION C, Issue 8 2009
Qing-Wei Wang
In the title coordination compound, [Mn(C8H10O4)(C14H14N4)(H2O)2]n, each MnII centre occupies an inversion centre. The 1,4-bis(imidazol-1-ylmethyl)benzene (1,4-bix) ligand and the trans -cyclohexane-1,4-dicarboxylate dianion (chdc) both function in bridging modes, linking adjacent MnII centres into a two-dimensional four-connected (4,4) network. These two-dimensional layers are stacked in a parallel mode. Hydrogen bonds between water molecules and carboxylate O atoms link neighbouring (4,4) networks, yielding a three-dimensional ,-polonium net. [source]

Poly[[[,-1,1,-(butane-1,4-diyl)diimidazole-,2N:N,](,-cyclohexane-1,4-dicarboxylato-,4O1,O1,:O4,O4,)cadmium(II)] hemihydrate]: a parallel interpenetrating two-dimensional (4,4) network

ACTA CRYSTALLOGRAPHICA SECTION C, Issue 2 2009
Shi Zhou
In the title coordination compound, {[Cd(C8H10O4)(C10H14N4)]·0.5H2O}n, the 1,1,-(butane-1,4-diyl)diimidazole ligand and the cyclohexane-1,4-dicarboxylate dianion both function in a bridging mode to link adjacent cadmium(II) centers into a two-dimensional four-connected (4,4) network. The networks are parallel to the (001) plane. Two (4,4) networks are interpenetrated in an unusual parallel mode. The compound is the first two-dimensional parallel interpenetrating (4,4) network structure based on a flexible dicarboxylate and a long bidentate N -donor ligand. The interpenetrating nets are further consolidated by water,carboxylate O,H...O hydrogen bonds. [source]

Lysine-based peptide nucleic acids (PNAs) with strong chiral constraint: Control of helix handedness and DNA binding by chirality

CHIRALITY, Issue S1 2005
Tullia Tedeschi
Abstract Two enantiomeric chiral PNAs bearing three adjacent d - or l -lysine-based residues in the middle of the strand ("chiral box" PNAs, sequence H-GTAGALysTLysCLysACT-NH2) have been used as models in order to comprehensively study the effects of the stereogenic centers on PNA conformation and on PNA binding properties to complementary PNA and DNA strands. The binding properties of the two enantiomeric PNAs and of their homologous achiral PNA have been extensively studied by UV and CD spectroscopy and by mass spectrometry, both in the antiparallel and in the parallel mode with complementary PNA and DNA strands. In the antiparallel PNA:PNA duplexes, l -Lys PNA were found to form left-handed, and d -Lys PNA right handed helices, while in parallel duplexes, the reversed helicities were observed. Correspondingly, the preferred mode of binding and the best mismatch recognition of the d -Lys containing PNA with (right handed) DNA was found to be in the antiparallel orientation, while that of l -Lys PNA was found to be in the parallel mode. A rationale which correlates the preferred handedness of the PNA-PNA duplexes to the directionality of the binding to complementary DNA duplexes has been devised according to structural data and considering the "retro,inverso" concept widely used for peptides. Chirality 17:S196,S204, 2005. © 2005 Wiley-Liss, Inc. [source]