N‐Fusion Approach in Construction of Contracted Carbaporphyrinoids: Formation of N‐Fused Telluraporphyrin

Insertion of PCl₃ into 5,10,15,20‐tetraaryl‐21‐telluraporphyrin leads to a phosphorus complex of N‐fused dihydrotelluraporphyrin with an inverted tellurophene ring. Its CNN coordination core places the macrocycle in the family of contracted carbaporphyrinoids. A cycle of direct transformations affords an elegant triangle of three mutually convertible N‐fused porphyrinoids, with distinct spectroscopic features: antiaromatic, nonaromatic and aromatic. The nonaromatic species has a dome shaped skeleton which forms in the solid state a ball and socket structure with C₆₀.     

Microcomputer-controlled insturmentation for voltammetric techniques

A simple computer system for conducting voltammetric experiments is described. An Atari 800 XL microcomputer is connected to a laboratory-made analog/digital voltammetric analyzer by means of a two-directional serial transmission interface. The serial transmission makes it possible to decrease the number of connectors, which allows optical coupling between the microcomputer and other parts of the system. The system provides the user with computer-aided execution of experiments, including synthesis of potential waveforms and collection and development of responses. The performance of the hardware system is demostrated by its application in determining cadmium at the ng 1^-1 level in a solution of Suprapur sulphuric acid by background-corrected anodic stripping voltammetry with a deposition time of 180 s and a scan rate of 9 V s^-1.     

Volta potential at metal-solid salt interface and real potentials of ions in solid electrolytes

Experimental conditions and results of investigations of Volta potentials of metal-solidelectrolyte and solid electrolyte-aqueous electrolyte solution by means of the dynamic condenser method are presented. These investigations were made for silver-silver halides and silver-silver nitrate as well as for cadmium-cadmium halide systems. On the basis of measured Volta potentials the real potentials of ions in these solid electrolytes are calculated. These real potentials are the ionic components of the crystalline lattice energy in the sense of the Gibbs energy.     

Forthcoming articles

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Forthcoming articles     

A direct link between annulene and porphyrin chemistry--21-vacataporphyrin

A novel molecule, aza-deficient porphyrin 5,10,15,20-tetraaryl-21-vacataporphyrin has been synthesised by a substraction of a tellurium atom from 5,10,15,20-tetraaryl-21-telluraporphyrin under treatment of HCl. The new macrocycle is an annulene-porphyrin hybrid and at the same time is directly related to 21-heteroporphyrins but has a vacant space instead of heteroatomic bridge. The molecule preserves the fundamental structural and spectroscopic features of the parental 5,10,15,20-tetraarylporphyrin with three nitrogen atoms and two CH groups favorably prearranged for coordination.     

Simultaneous analysis of biologically active aminoalkanephosphonic acids

A new approach for simultaneous analysis of biologically active aminoalkanephosphonic acids, namely glyphosate, phosphonoglycine, phosphonosarcosine, phosphonoalanine, phosphono-beta-alanine, phosphonohomoalanine, phosphono-gamma-homoalanine and glufosinate, is presented. This includes a preliminary 31p NMR analysis of these amino acids, their further derivatization to volatile phosphonates (phosphinates) by means of trifluoroacetic acid-trifluoroacetic anhydride-trimethyl orthoacetate reagent and subsequent analysis of derivatization products using MS and/or GC-MS (chemical ionization and/or electron impact ionization).     

Protein-calixarene interactions: complexation of Bovine Serum Albumin by sulfonatocalix[n]arenes

The complexation of Bovine Serum Albumin with sulfonatocalix[n]arenes has been demonstrated by means of electrospray mass spectrometry, dynamic light scattering and atomic force microscopy; with sulfonatocalix[4]arene one strong and two weaker binding sites are detected; the effects on the structure of thin films formed by surface deposition of BSA show that the sulfonatocalix[n]arenes act to reticulate the films and produce essentially planar systems.