First Aqueous Chemistry with Seaborgium (Element 106)

Extraction of the fluoride-, chloride- and bromide complexes of the elements Nb, Ta, Pa, and 105 into aliphatic amines

Abstract Previous studies of the halide complex formation of element 105 in HCl–HF mixtures and extractions into triisooctyl amine (TIOA) have been performed with the Automated Rapid Chemistry Apparatus, ARCA II. Element 105 was shown to be absorbed on the column from 12 M HCl–0.02 M HF together with its lighter homologues Nb, Ta and the pseudohomologue Pa. In elutions with 10 M HCl–0.025 M HF, 4 M HCl–0.02 M HF, and 0.5 M HCl–0.01 M HF, the extraction sequence Ta>Nb>105>Pa was observed and element 105 behaved very differently from its closest homologue Ta. As it is not possible within reasonable effort to model the many presumably mixed fluoride–chloride complexes involved in these studies…

Molecular Scale Study of Domain Boundaries and Frictional Stick-Slip Motion on Lipid Bilayers

A highly 2-dimensional (2D) anisotropic crystal formation of an organic one component lipid bilayer system is presented measured in air by atomic force microscopy. 2D domains with different crystal orientation could be observed. Their molecularly smooth domain boundaries are perceived to be either commensurable or incommensurable lattice joints. Differences in the orientation of the crystal lattice affects dynamic friction on the micrometer scale. High resolution friction images provide stick-slip motions depending on the scan direction in respect to the lattice orientation. It is shown that sliding friction can be determined by an averaged value of the molecular stick-slip motion of the fr…

Relationship between microscopic and macroscopic structures of organic thin films for SHG

The experiments described in this paper were undertaken in order to obtain information about the relationship between the structure and non-linear optical properties (second-harmonic generation) of organic thin films. For this purpose, two closely related dyes, diones and tetrones, were compared, both of which are shown to have large hyperpolarisabilities. Their microscopic properties are investigated by conformational analysis and electron diffraction. It could be shown that detailed knowledge about the structure and the adjacent neighbour packing can be obtained from conformational analysis and electron diffraction in order to understand the non-linear optical properties of the two dyes.

Second harmonic generation in self-assembled alternating multilayers of hemicyanine containing polymers and polyvinylamine

Abstract Assembly of noncentrosymmetric multilayers is a facile technique for preparing noncentrosymmetric films avoiding electrical poling procedures and problems from subsequent relaxation of the induced orientational order. A maximum Xzzz of 13 × 10−9 esu was achieved for the assembly of up to six layers. Current problems are the long-term hydrolysation of the hemicyanine nonlinear optical chromophores and the reduction of polar orientation with increasing layer thickness.

Ansiotropy in friction and molecular stick-slip motion

Columnar phases from semi-discoid molecules. Phase induction via hydrogen bonding and charge transfer interactions

Abstract To investigate the non-linear optical properties of nitrophenylhydrazones, a series of 4-nitro- and 2,4-dinitrophenylhydrazones of substituted aromatic aldehydes were synthesized. It was found that many of the dinitrophenythydrazone derivatives are liquid-crystalline and X-ray investigations show that the mesophase corresponds to a hexagonal columnar structure. To explain this unusual behaviour it is necessary to assume that a mesogenic structure is formed by intramolecular hydrogen bonding of the dinitrophenylhydrazones. Charge transfer induced antiparallel alignment of these moleculer dipoles leads to discoid structures, forming the columnar phases.

Structures, properties and miscibility behaviour of liquid crystalline polycatenar tetrone derivatives

Abstract The tetrones represent an interesting new mesogenic building block. The results of this study show that they can be incorporated into a variety of mesophases. A smectic phase was observed in the polycatenar compound with four terminal chains as expected. The phase exhibits a tilted structure (Sc phase) to prevent void formation. The compound with six pendant chains forms a columnar phase. In spite of their structural similarity, the tetrones studied tended not to be completely miscible. However, complete miscibility with a semi-discoid phenylhydrazone was observed. When this hydrazone, which forms a columnar ‘Dho phase’, was mixed with tetrone which forms a columnar ‘Dhd phase’ a c…

CCDC 109335: Experimental Crystal Structure Determination

Related Article: T.M.Bohanon, P.-L.Caruso, S.Denziger, R.Fink, D.Mobius, W.Paulus, J.A.Preece, R.Helmut, D.Schollmeyer|1999|Langmuir|15|174|doi:10.1021/la980348w

CCDC 622051: Experimental Crystal Structure Determination

Related Article: I.Mata, E.Espinosa, E.Molins, S.Veintemillas, W.Maniukiewicz, C.Lecomte, A.Cousson, W.Paulus|2006|Acta Crystallogr.,Sect.A:Found Crystallogr.|62|365|doi:10.1107/S0108767306025141

CCDC 622037: Experimental Crystal Structure Determination

Related Article: I.Mata, E.Espinosa, E.Molins, S.Veintemillas, W.Maniukiewicz, C.Lecomte, A.Cousson, W.Paulus|2006|Acta Crystallogr.,Sect.A:Found Crystallogr.|62|365|doi:10.1107/S0108767306025141

CCDC 622036: Experimental Crystal Structure Determination

Related Article: I.Mata, E.Espinosa, E.Molins, S.Veintemillas, W.Maniukiewicz, C.Lecomte, A.Cousson, W.Paulus|2006|Acta Crystallogr.,Sect.A:Found Crystallogr.|62|365|doi:10.1107/S0108767306025141

CCDC 622035: Experimental Crystal Structure Determination

Related Article: I.Mata, E.Espinosa, E.Molins, S.Veintemillas, W.Maniukiewicz, C.Lecomte, A.Cousson, W.Paulus|2006|Acta Crystallogr.,Sect.A:Found Crystallogr.|62|365|doi:10.1107/S0108767306025141