Nuclear Magnetic Resonance

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It is known that atoms with uneven number of mass or prtons (atomic number) generate magnetic field, when submitted the spinnings. The sweepings of a magnetic field and the induced voltage compose a graph, whose signals if relate with ‘ ‘ ambientes’ ‘ chemistries of atoms in study, what it can be used in the identification (for structural determination) of gotten organic composites of syntheses or natural extrations. In the case of the Nuclear Magnetic Hydrogen Resonance (RMN 1H), the electronic density of a hydrogen atom influences in the effect ‘ ‘ blindagem’ ‘ of this atom, front to a magnetic field, in way that, how much lesser it will be the electronic density, less ‘ ‘ blindado’ ‘ it will be the hydrogen atom in study. An increase in the shield implies, also, in the increase of the necessary energy for the vibration, meaning increase in the frequency and the field. Comparing hydrogen atoms of molecules of iodometano and methanol, bigger shield in the first composition is verified.

This can be explained on the basis of the eletronegatividade difference enters iodine and oxygen atoms: in methanol, it has a lesser electronic density on hydrogen atoms, therefore ‘ ‘ eltrons’ ‘ strong they are attracted by the oxygen and, therefore, these hidrognios possess minor shield. As the iodine atom is less eletronegativo of what of oxygen, the electrons of hydrogen atoms of the iodometano are more weakly attracted (if compared with the ones of methanol), favoring a bigger electronic density in the hidrognios of the iodometano, that, for in such a way, can be said ‘ ‘ more blindados’ ‘ in relation to the ones of methanol. One notices, that the eletronegatividade also is a factor of influence in this study. The hydrogen atom (h) is eletronegativo of what of silicon (Itself), for in such a way, in the tetrametilsilano composition (TMS), with formula (CH3) 4Si, the hidrognios are ‘ ‘ well blindados’ ‘ (with raised electronic density).