Croatica Chemica Acta, Vol. 78 No. 4, 2005.
Original scientific paper
Nitrosobenzene Library: A Model for Studying Selectivity in the Solid State Nitroso-Azodioxide Dimerization
Vesna Šimunić-Mežnarić
Ernest Meštrović
Vladislav Tomišić
Marijana Žgela
Dražen Vikić-Topić
Helena Čičak
Predrag Novak
Hrvoj Vančik
Abstract
Cross-linking of nitroso benzenes to heterodimers (azodioxides), in the case when they are not sterically crowded with large groups in ortho-position, was studied by NMR, UV-VIS, and Raman spectroscopy as well as by powder X-ray crystallography. Dimerization of nitroso compounds to azodioxides can, in principle, be used for the construction of novel supramolecular structures. As a preliminary investigation, the selectivity of nitrosobenzenes to form dimers in the solid state was studied. Observations by NMR and vibrational spectroscopy show that selectivity for cross-linking is quite different in the solid state from that in solution. This is explained by a considerable influence of packing factors in the former. Selectivities for cross- -linking in the solid state in a complex chemical library of monomers were formulated and measured using simple spectroscopic and diffraction methods. For every member of such a nitrosobenzene chemical library it is possible to measure and, using the Tanimoto similarity coefficients, calculate two selectivity parameters, chemical selectivity and packing selectivity. While packing selectivity is correlated with total dipole moments of nitroso monomer molecules, chemical selectivity is in correlation with the x-component of the molecular dipole, i.e., the axis that is nearly collinear with the C-N bond in nitroso group. The method developed in this work could, in principle, be proposed for more general use in investigations of similar chemical libraries with binary combined components.
Keywords
solid state reactivity; solid state selectivity; nitroso compounds; chemical library
Hrčak ID:
2538
URI
Publication date:
20.12.2005.
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