摘要:

The crystal and molecular structure of [N(CH2CH2OH)3]NaI has been established by a three‐dimensional single‐crystal X‐ray analysis. The crystals are triclinic, space groupPĪ and have two molecules per asymmetric unit witha= 7.693,b= 7.559,c= 9.29 Å, α = 102.16°, β=91.47°, γ = 93.02°. The structure was solved by the heavy‐atom method from data collected at room temperature on a four‐circle diffractometer using the θ‐2θ scan technique. It was refined by the least‐squares method toR= 0.046 for 2420 reflexions. The structure of the seven‐coordinated complex of sodium is described and discussed. Two OH groups of each molecule bridge two sodium cations. Each sodium cation is thus bonded to the four heteroatoms of one ligand molecule, two oxygen atoms of a neighbouring ligand and to the iodine anion. The crystal structure consists of

ISSN:0567-7408    

DOI:10.1111/j.1600-5740.1974.tb00011.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

The molecular structure of {[N(CH2CH2OH)3]2Sr}(NO3)2has been determined by single‐crystal X‐ray diffraction. Crystals are monoclinic, space groupC2/c, Z>= 4,a= 17.972,b= 8.662,c= 14.112 Å, β = 104.50°. The structure was solved by the heavy‐atom method from three‐dimensional data collected on a four‐circle diffractometer. The structure consists of eight‐coordinated Sr2+ions. The strontium ion is surrounded by eight heteroatoms of two TEA ligands. The coordination polyhedron of the Sr2+is approximately cubic. The two nitrate groups are not linked to the cation, but interact with the OH groups of the TEA ligands in strong

ISSN:0567-7408    

DOI:10.1111/j.1600-5740.1974.tb00012.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

A three‐dimensional X‐ray crystal structure analysis has been carried out on a complex formed from ethanol 2,2‘,2“‐nitrilotriacetate and barium acetate, BaN2O10C16H36. Crystals are triclinic,a= 11.915 (4),b= 10.317 (7),c= 11.223 (9) Å, α = 118.59 (4)°, β = 98.57° (6), γ = 91.98 (5)°, space groupPĪ withZ= 2. The structure was solved by the heavy‐atom method and refined by the block‐diagonal least‐squares technique to a finalRvalue of 0.031, using 4212 three‐dimensional diffractometer‐collected single‐crystal X‐ray data. The barium cation is bonded to the heteroatoms of two TEA ligands and an oxygen atom of an acetate group. The distance between Ba2+and the second acetate group is greater than 5 Å. Hydrogen bonds occur in the solid state between the OH group of the TE

ISSN:0567-7408    

DOI:10.1111/j.1600-5740.1974.tb00013.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

The term ‘OD packet’ is defined as the smallest continuous part of an OD structure consisting ofM>1 kinds of layers which is periodical in two dimensions and which completely represents its composition. The properties of OD packets in the four categories are discussed and their application to kaolinite‐type and MoS2polytypes is

ISSN:0567-7408    

DOI:10.1111/j.1600-5740.1974.tb00014.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

9‐Ethylguanine, C7H9N5O, crystallizes in the tetragonal space groupP41212 with cell dimensionsa(=b) = 10.907 (1),c= 29.370 (2) Å. There are 16 molecules per unit cell, or two per asymmetric unit. The structure was derived by symbolic addition and tangent refinement, based on 15294 σ2relationships among the 207 reflections withEgreater than 1.49. Refinement by least squares led to anRindex of 0.067 for 1988 reflections. Pairs of N(1)‐H … N(7) and NH2… O hydrogen bonds along non‐crystallographic twofold screw axes form ribbons of molecules along [100] and [010]; pairs of ribbons are stacked on top of one another with a separation of about 3.4 Å. In both molecules the terminal CH2‐CH3bond is oriented approximately perpendicular to the plane of t

ISSN:0567-7408    

DOI:10.1111/j.1600-5740.1974.tb00015.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

C9N3O5H13, orthorhombic, space group P212121,a= 7.42,b= 8.46,c= 16.1 Å,Z= 4,V= 1030 Å3,d= 1.67 g cm−3. The final residualRis 0.064 for a three‐dimensional set of 1220 reflexions collected on Weissenberg photographs. An internal hydrogen bond between the O(2′)H donor group and O(5′) acceptor atom stabilizes the C(2′)endoconformation of the sugar and restricts the free rotation about the glyc

ISSN:0567-7408    

DOI:10.1111/j.1600-5740.1974.tb00016.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

Monoclinic,P21,a= 14.316 (2),b= 6.085(2),c= 13.423 (2) Å, β=100.52°,M= 441.6,Z= 2,Dx, = 1.28 g cm−3, μ = 7.0 cm−1. Torsional angles C(16)‐C(17)‐C(20)‐O(20) and O(20)‐C(20)‐C(21)‐O(21) equal −29.7° and −6.2° respectively. Bonding between Cortisol and pyridine occurs through the H bond O(17)‐H … N [d= 2.823 (7) Å]. The cohesion of the crystal is effected by this bond, interactions between O (11), O(20) and O(21),

ISSN:0567-7408    

DOI:10.1111/j.1600-5740.1974.tb00017.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

Crystals of 5‐methoxytryptamine (C11H14N2O) are monoclinic, space groupPc; a= 6.110 (2),b= 9.532 (3),c= 8.831 (3) Å, β=98.72 (1)°,Z= 2,Dm= 1.242,Dx= 1.245 g cm−3. The structural model was refined toR= 0.025 for 746 independent X‐ray reflections measured with an automatic diffractometer. The indole ring system deviates from planarity by small but significant amounts which correspond to a bending in the benzene ring. The ethylamine side chain is in the bent (gauche) conformation rather than fully extended. Each indole nitrogen atom donates its hydrogen atom to form a hydrogen bond to the amine nitrogen of the next molecule, with N‐N = 2

ISSN:0567-7408    

DOI:10.1111/j.1600-5740.1974.tb00018.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

Crystals of melatonin (C13H16N2O2) are monoclinic, space groupP21/c; a= 7.707 (2),b= 9.252 (2),c= 17.077 (4) Å, β = 96.78 (3)°,Z= 4,Dm= 1.272,Dx= 1.276 g cm−3. The structural model was refined toR= 0.036 for 900 independent X‐ray reflections measured on an automatic diffractometer. The molecules are nearly flat with the side chain in the fully extended (trans) conformation. Molecules are connected in sheets by weak hydrogen bonds from nitrogen to oxygen, with N‐O = 2.90 an

ISSN:0567-7408    

DOI:10.1111/j.1600-5740.1974.tb00019.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

The structure of μ‐carbonato‐bis(tetraphenylantimony),, has been determined from 2394 independent X‐ray intensities measured on a four‐circle diffractometer. The material is triclinic, space groupP1, witha= 10.108,b= 14.018,c= 15.702 Å, α = 73.92, β = 79.84, β = 74.39°,Z= 2. The structure was solved by the heavy‐atom method and refined by least‐squares calculations toR= 0.049. The structure consists of well separated molecules. One antimony atom, Sb(1), is in a slightly distorted trigonal bipyramidal environment with a carbonato oxygen apical. The mean C(axial)‐Sb(1)‐C(equatorial) angle is 95.2° and corresponds to a displacement of Sb(1) 0.19 Å out of the plane of the three equatorial carbon atoms towards the apical phenyl group. The other antimony, Sb(2), has distorted octahedral coordination. The two antimony polyhedra are linked by a planar carbonato group whose C‐O distances do not differ significantly from their mean value 1.292 (13) Å. The Sb‐O distances are Sb(1)‐O(1), 2.257 (7), Sb(2)‐O(2) 2.325 (7), Sb(2)‐O(3) 2.185 (7). At Sb(1), the mean Sb‐C (equatorial) bond length is 2.120 (11) and the Sb‐C(apical) distance is 2.153 (11) Å. The mean val

ISSN:0567-7408    

DOI:10.1111/j.1600-5740.1974.tb00020.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY