Systems of Hess-Appel'rot type

We construct higher-dimensional generalizations of the classical Hess-Appel'rot rigid body system. We give a Lax pair with a spectral parameter leading to an algebro-geometric integration of this new class of systems, which is closely related to the integration of the Lagrange bitop performed by us recently and uses Mumford relation for theta divisors of double unramified coverings. Based on the basic properties satisfied by such a class of systems related to bi-Poisson structure, quasi-homogeneity, and conditions on the Kowalevski exponents, we suggest an axiomatic approach leading to what we call the "class of systems of Hess-Appel'rot type".Comment: 40 pages. Comm. Math. Phys. (to appear

New terpyridine derivatives of thiacalix[4]arenes in solution and at the water-air interface

© 2020, Springer Science+Business Media LLC. New di- and tetrasubstituted thiacalix[4]arenes in cone and 1,3-alternate configurations containing terpyridine and triazole fragments at the lower rim of the macrocycle, as well as model triazole-terpyridine, are synthesized. The structures and purity of the compounds are confirmed by NMR spectroscopy and high-resolution MALDI mass spectrometry. The compounds form luminescent complexes with lanthanide cations (europium and terbium) in a chloroform-methanol (10: 1) system during fluorimetric titration. The possibility of antenna ef ect during fluorescence sensitization in lanthanides by the thiacalixarene ligands is demonstrated. Successful immobilization of the terpyridine receptors on a solid substrate makes it possible to consider the Langmuir-Blodgett films on the basis of these receptors as promising adsorbents of lanthanide from nonaqueous media or organic salts and also provides new opportunities for the investigation of the luminescence characteristics of lanthanide complexes in thin films