| | 1 | Author
| R. Alf Steudel, Angela Albertsen, M. Onika Kustos, Joachim Pickardt | Requires cookie* | | | Title
| X-Ray Structural Analysis and Vibrational Spectra of Sodium Cysteine-S-sulfonate, +H3N C H (C 0 0 )CH 2S 20 3Na -3 /2 H 20 [1]  | | | | Abstract
| The title com pound crystallizes orthorhombically (space group C 222,) with a = 797.0, b = 870.3 and c = 2739.0 pm. The anions are zwitterions which are heavily involved in intra-and intermolecular NH --O and OH -O hydrogen bonding. The two types o f sodium cations are coordinated by six oxygen atoms each o f which belongs to either S 0 3 groups (N a 2) or water molecules and S 0 3 groups (N a l). A second type o f water molecules is not coordinated to the cations. The SS bond length is 208.2 pm. Infrared and Raman spectra o f the title com pound are reported and tentatively assigned. The SS stretching vibration is observed at 409 cm -1. | | | |
Reference
| Z. Naturforsch. 48b, 555—560 (1993); received July 23 1992 | | | |
Published
| 1993 | | | |
Keywords
| Cysteine, S-Sulfonate, Structure, Spectra, Hydrogen Bonds | | | |
Similar Items
| Find | | | DEBUG INFO
| | | | | TEI-XML for
| default:Reihe_B/48/ZNB-1993-48b-0555.pdf | | | | Identifier
| ZNB-1993-48b-0555 | | | | Volume
| 48 | |
| 2 | Author
| Ivar Olovsson, Halina Ptasiewicz-Bak, GarryJ. Mclntyre | Requires cookie* | | | Title
| Superposition and Polarization Effects on the Electron Density of Lone Pairs | | | | Abstract
| There appears to be conflicting experimental evidence on the redistribution of the electron density in the lone-pair and other regions of a molecule due to the interaction with its nearest neighbours. In some experimental as well as theoretical deformation density maps a decrease in the lone-pair density has been reported, whereas in other cases an increase has been found. It appears that two major, counteracting factors are responsible for these differences (apart from experimental errors in the diffraction studies and limited accuracy in the theoretical calculations): an increase in the lone-pair density is expected due to the polarizing influence of the neighbours, whereas simple superposition of the isolated monomer deformation densities will lead to an apparent decrease due to the overlap with the negative contours of the neighbouring atom. Depending on which of these factors is the dominant one, an increase or decrease may thus be observed. These points are illustrated by recent results on nickel sulfate hexahydrate and some other hydrogen-bonded compounds. The electron density based on the fitted deformation functions of all atoms in the structure is compared with the individual densities calculated from deformation functions of the separate monomers. In this way the effects of simple superposition of the individual densities have been studied, and a partitioning of the electrostatic and polarization contributions to the hydrogen bonds and other relatively weak bonds to the oxygen lone-pairs attempted. | | | |
Reference
| Z. Naturforsch. 48a, 3—11 (1993); received January 30 1992 | | | |
Published
| 1993 | | | |
Keywords
| Electron density, Superposition effects, Polarization effects, Lone pairs, Hydrogen bonds | | | |
Similar Items
| Find | | | DEBUG INFO
| | | | | TEI-XML for
| default:Reihe_A/48/ZNA-1993-48a-0003.pdf | | | | Identifier
| ZNA-1993-48a-0003 | | | | Volume
| 48 | |
|
