Mössbauer study of a new crystalline fluoride: NaPbFe2F9

Mössbauer spectrometry was carried out over the temperature range 4.2 K-300 K on a crystalline fluoride NaPbFe₂F₉, which orders antiferromagnetically below 116 K. The hyper-fine data are discussed in terms of the position and the environment of iron sites.     

Langmuir and Langmuir-Blodgett films of a novel tryptophan peptide lipid

A novel tryptophan peptide lipid, C18H35O (SA)-Gly-Trp-Gly-OH, was synthesized and studied for its surface chemistry and spectroscopic properties.     

Study of Self‐Assembly of the Lignin Model Compound on Cellulose Model Substrate

Herein we report a topographical study of the supramolecular organization of enzymatically polymerized lignin model compound – dehydrogenative polymer (DHP) of coniferyl alcohol – on cellulose substrate, using the Environmental Scanning Electron Microscopic (ESEM) technique. A comparison of deposits obtained by bulk polymerization in solution and direct polymerization in the presence of cellulose substrate shows distinct differences in supramolecular organization. DHP polymerized in solution expresses a 3‐D structure with short‐range ordered motifs, while the polymer formed in the presence of cellulose substrate arranges in a single layer compact structure consisting of several domains. Such structures could be described as a two‐dimensional hexagonal close packed lattice(HCPL), with the dimension of unit cell in 1 μm range. The domains have a quite regular structure with few lattice defects, forming a good example of two‐dimensional colloidal crystal. The growth of DHP globules and their assembly into supramolecular structures are interpreted in terms of cooperative electrostatic interaction of polymer precursors, with a framework of cellulose OH groups and interfacial interactions (hydrophilic/hydrophobic) in the course of the structure growth. The results strongly suggest that the carbohydrate matrix in plant cells can serve as a template for lignin structure formation in the plant cell wall.

Self‐assembled lignin model compound on cellulose substrate.     

Colchicine fluorescence measured with a laser spectrofluorimeter

A laser spectrofluorimeter is used to observe the fluorescence from colchicine, α-methoxy-tropone and tropolone in aqueous solutions at room temperature.     

Mössbauer and optical evidence for a crystallographic transition in AFeF4 compounds

The thermal variation of the quadrupole splitting of ⁵⁷Fe in NH₄FeF₄ and RbFeF₄ gives a strong evidence of a phase transition taking place at 120° and 110°C respectively. Birefringence in the a, b plane is observed at room temperature and disappears when approaching the reported temperatures. KFeF₄ does not show any sizeable change in the range 20–200°C. CsFeF₄ behaves in a more complicated way and does not lead to definite conclusions.