How to calculate number of electrons pair in NO2 by AVSEPR theory?
How to calculate number of electrons pair in NO2 by AVSEPR theory?
The premise of VSEPR is that the valence electron pairs surrounding an atom tend to repel each other and will, therefore, adopt an arrangement that minimizes this repulsion, thus determining the molecule's geometry. Gillespie has emphasized that the electron-electron repulsion due to the Pauli exclusion principle is more important in determining molecular geometry than the electrostatic repulsion.
VSEPR theory mainly concentrate on the geometry of molecule.the electronic configuration will the same according to Pauli's exclusion principal.
But an exceptional case in NO2 is given below
Another complication crops up when there are unpaired electrons. This is well illustrated for nitrogen dioxide. So, for NO2 there is an integral number of electrons but a non-integral number of electron pairs. Since any orbital can accommodate 0, 1, or 2 electrons, 21/2 electron pairs must be placed into three orbitals. Therefore the geometry is based upon a trigonal-planar arrangement of electron pairs. Since the lone-pair orbital is only half filled, it demands less space, and the O-N-O angle opens out a little (to 134.1°) from the ideal trigonal angle of 120°.
Addition of one electron to NO2 gives the nitrite anion NO2-. This last electron completes the half-occupied lone-pair orbital and this filling of the orbital causes it to fill out, and so close the O-N-O bond angle to 115°.
The premise of VSEPR is that the valence electron pairs surrounding an atom tend to repel each other and will, therefore, adopt an arrangement that minimizes this repulsion, thus determining the molecule's geometry. Gillespie has emphasized that the electron-electron repulsion due to the Pauli exclusion principle is more important in determining molecular geometry than the electrostatic repulsion.
VSEPR theory mainly concentrate on the geometry of molecule.the electronic configuration will the same according to Pauli's exclusion principal.
But an exceptional case in NO2 is given below
Another complication crops up when there are unpaired electrons. This is well illustrated for nitrogen dioxide. So, for NO2 there is an integral number of electrons but a non-integral number of electron pairs. Since any orbital can accommodate 0, 1, or 2 electrons, 21/2 electron pairs must be placed into three orbitals. Therefore the geometry is based upon a trigonal-planar arrangement of electron pairs. Since the lone-pair orbital is only half filled, it demands less space, and the O-N-O angle opens out a little (to 134.1°) from the ideal trigonal angle of 120°.
Addition of one electron to NO2 gives the nitrite anion NO2-. This last electron completes the half-occupied lone-pair orbital and this filling of the orbital causes it to fill out, and so close the O-N-O bond angle to 115°.
