First crystal structure of an Fe(III) anionic complex based on a pyruvic acid thiosemicarbazone ligand with Li: synthesis, features of magnetic behavior and theoretical analysis.

The iron(III) anionic complex based on a pyruvic acid thiosemicarbazone ligand with the lithium cation Li[Fe(thpy)]·3HO (1) has been synthesized and characterized by FTIR spectroscopy, powder and single crystal X-ray diffraction, direct current magnetic susceptibility measurements, and Fe Mössbauer spectroscopy. Moreover, the molecular structure of the [Fe(thpy)] anion has been determined for the first time. The [Fe(thpy)] units in the triclinic 1̄ lattice of 1 are assembled into layers parallel to the plane.

Peculiar Spin-Crossover Behavior in the 2D Polymer K[Fe(5Cl-thsa)].

A potassium salt of the NSO-coordination Fe(III) anion K[Fe(5Cl-thsa)] () (5Cl-thsa - 5-chlorosalicylaldehyde thiosemicarbazone) is synthesized and characterized structurally and magnetically over a wide temperature range. Two polymorphs of salt characterized by the common 2D polymer nature and assigned to the same orthorhombic space group have been identified. The molecular structure of the minor polymorph of was solved and refined at 100, 250, and 300 K is shown to correspond to the LS configuration.

Spin-crossover behavior of neutral iron(iii) complexes with salicylaldehyde thio-, seleno- and semicarbazone ligands: experiment and theoretical analysis.

The iron(iii) complex [Fe(Hsemsal)(semsal)]·3H2O (1) (H2semsal - salicylaldehyde semicarbazone) has been synthesized and characterized by powder and single crystal X-ray diffraction, and magnetic susceptibility measurements. Crystal structure analysis showed that the complex forms neat stacks stabilized by hydrogen-bonding through water molecules and π-π interactions between phenolate rings of ligands. The complex does not exhibit spin-crossover phenomena and remains in the high-spin state down to 2 K.

Insights into the influence of ethylene group orientation on the iron(iii) spin state in the spin crossover complex [Fe(Sal-trien)].

The DFT calculations of the spin crossover complex [FeIII(Sal2-trien)]+ (1) with the following classification of conformers of 1 were performed. The study shows that rearrangements of ethylene group orientation in a coordinated ligand lead to the stabilization of the high-spin or low-spin iron(iii) state.

Dynamical analysis of regulatory interactions in the gap gene system of Drosophila melanogaster.

Genetic studies have revealed that segment determination in Drosophila melanogaster is based on hierarchical regulatory interactions among maternal coordinate and zygotic segmentation genes. The gap gene system constitutes the most upstream zygotic layer of this regulatory hierarchy, responsible for the initial interpretation of positional information encoded by maternal gradients. We present a detailed analysis of regulatory interactions involved in gap gene regulation based on gap gene circuits, which are mathematical gene network models used to infer regulatory interactions from quantitative gene expression data.

Dynamic control of positional information in the early Drosophila embryo.

Morphogen gradients contribute to pattern formation by determining positional information in morphogenetic fields. Interpretation of positional information is thought to rely on direct, concentration-threshold-dependent mechanisms for establishing multiple differential domains of target gene expression. In Drosophila, maternal gradients establish the initial position of boundaries for zygotic gap gene expression, which in turn convey positional information to pair-rule and segment-polarity genes, the latter forming a segmental pre-pattern by the onset of gastrulation.

A database for management of gene expression data in situ.

Motivation: To create a spatiotemporal atlas of Drosophila segmentation gene expression at cellular resolution.

Results: The expression of segmentation genes plays a crucial role in the establishment of the Drosophila body plan. Using the IBM DB2 Relational Database Management System we have designed and implemented the FlyEx database.