Crystal Structure and Hydrogen Bonding System in Cellulose Iαfrom Synchrotron X-ray and Neutron Fiber Diffraction

2003 ◽  
Vol 125 (47) ◽  
pp. 14300-14306 ◽  
Author(s):  
Yoshiharu Nishiyama ◽  
Junji Sugiyama ◽  
Henri Chanzy ◽  
Paul Langan
2006 ◽  
Vol 62 (7) ◽  
pp. o2951-o2952 ◽  
Author(s):  
Si-Min Wu ◽  
Ming Li ◽  
Jiang-Feng Xiang ◽  
Liang-Jie Yuan ◽  
Ju-Tang Sun

The crystal structure of the title compound, C2H10N2 2+·C6H2O4S2−·2H2O, is built of ethylenediammonium dications, occupying a special position on an inversion center, thiophene-2,5-dicarboxylate dianions, in a special position on the twofold axis, and water molecules in general positions. All residues are involved in an extensive hydrogen-bonding system, which links them into a three-dimensional supramolecular arrangement.


2012 ◽  
Vol 68 (10) ◽  
pp. o405-o407 ◽  
Author(s):  
Vijayakumar N. Sonar ◽  
Sean Parkin ◽  
Peter A. Crooks

In the title compounds, C10H8N2O2, (I), and C12H12N2O2, (II), the two carbonyl groups are oriented with torsion angles of −149.3 (3) and −88.55 (15)°, respectively. The single-bond distances linking the two carbonyl groups are 1.528 (4) and 1.5298 (17) Å, respectively. In (I), the molecules are linked by an elaborate system of N—H...O hydrogen bonds, which form adjacentR22(8) andR42(8) ring motifs to generate a ladder-like construct. Adjacent ladders are further linked by N—H...O hydrogen bonds to build a three-dimensional network. The hydrogen bonding in (II) is far simpler, consisting of helical chains of N—H...O-linked molecules that follow the 21screw of thebaxis. It is the presence of an elaborate hydrogen-bonding system in the crystal structure of (I) that leads to the different torsion angle for the orientation of the two adjacent carbonyl groups from that in (II).


1976 ◽  
Vol 40 (314) ◽  
pp. 599-608 ◽  
Author(s):  
S. Menchetti ◽  
C. Sabelli

SummaryApjohnite, MnAl2(SO4)4·22H2O, is monoclinic, space group P21/c, a 6·198 (2), b 24·347 (4), c 21·266 (4) Å, β 100·28 (3)° and Z = 4. The crystal structure was determined by means of direct methods applied to X-ray data collected with a single-crystal diffractometer. At the end of the refinement, performed with least-squares method, the R index was 0·039.The SO4 tetrahedra, Al(H2O)5 octahedra, and MnO(H2O)5 octahedra are connected by a hydrogen bonding system; the only direct connection between polyhedra is by sharing of an oxygen between S(4) and Mn. In the asymmetric unit there are twenty-two water molecules, five of which lie in channels of the structure and are not linked to the cations but only to ligand water oxygens by means of hydrogen bonds.Powder data indicate a close structural relationship between apjohnite, halotrichite, and pickeringite.


1984 ◽  
Vol 62 (12) ◽  
pp. 2657-2660 ◽  
Author(s):  
F. D. Rochon ◽  
P. C. Kong ◽  
R. Melanson

Three types of complexes, trans-[Pt(LH)2Cl2], [Pt(L)2], and [Pt(LH)2(SR)2] where LH = NH2—C(CH3)2(CH2OH) and NH2—C(CH2OH)3 and L are the deprotonated ligands, have been synthesized.The crystal structure of trans-[Pt(NH2—C(CH3)2CH2OH)2Cl2] has been determined by X-ray diffraction methods. The crystals are monoclinic, space group P21/c, with a = 6,282(3), b = 20,901(13), c = 10,769(10) Å, β = 92,64(6)°, and Z = 4. The structure was refined by full-matrix least-squares analysis to a conventional R factor of 0.049 and Rw = 0.042. The coordination around the platinum atom is square planar. The Pt—Cl distances are 2.306(2) and 2.309(3) Å and the Pt—N bonds are 2.060(8) and 2.071 (7) Å. The hydroxyl oxygen atoms are disordered; the disorder is different for each organic ligand. The structure is stabilized by an extensive hydrogen bonding system.


2016 ◽  
Vol 72 (7) ◽  
pp. 1050-1053 ◽  
Author(s):  
Najla Mahbouli Rhouma ◽  
Ali Rayes ◽  
Francesco Mezzadri ◽  
Gianluca Calestani ◽  
Mohamed Loukil

The structure of the title non-centrosymmetric organic–inorganic hybrid salt, (C8H12NO)2[ZnCl4], consists of two 4-methoxybenzylammonium cations sandwiched between anionic layers, formed by isolated tetrachloridozincate tetrahedra. The double layers extend parallel to theacplane. The crystal packing is assured by Coulombic interactions and by a complex N—H...Cl and C—H...Cl hydrogen-bonding system mostly involving the positively charged ammonium groups and the chloride ligands of the isolated tetrahedral [ZnCl4]2−units. One of the methyleneammonium groups is disordered over two sets of sites in a 0.48 (2):0.52 (2) ratio. The crystal investigated was twinned by non-merohedry with a twin component ratio of 0.738 (2):0.262 (2).


Author(s):  
Kseniia O. Piletska ◽  
Kostiantyn V. Domasevitch ◽  
Alexander V. Shtemenko

In the molecule of the title compound, [Re(C5H10NO2)(CO)3(H2O)], the ReIatom adopts a distorted octahedral coordination sphere defined by one aqua and three carbonyl ligands as well as one amino N and one carboxylate O atom of the chelating valinate anion. The carbonyl ligands are arranged in afac-configuration around the ReIion. In the crystal, an intricate hydrogen-bonding system under participation of two O—H, two N—H and one C—H donor groups and the carboxylate and carbonyl O atoms as acceptor groups contribute to the formation of a three-dimensional supramolecular network.


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