The standard application of VSEPR theory to Chlorine trifluoride is as follows: In chlorine trifluoride, central atom is chlorine and valence electrons on central atom is 7. Also, contribution of three fluorine atoms is 1 electron each. Therefore, there are total 10 electrons or five electron pairs. As we know that the highest repulsion is between any two “lone electron pairs”, resulting in these moving apart as far as possible. The next highest repulsion is between one lone pair and a bond pair and the lowest is between two bond pairs.
As applied to chlorine trifluoride, it results in a trigonal bipyramidal geometry for the shape-determining five electron pairs. Three of these are bond pairs and two are lone pairs. These keep as far apart as possible, minimising repulsion between each of the negatively charged clouds by adopting a trigonal bipyramidal arrangement. The two lone pairs occupy equatorial position at an angle of 120° to each other, this gives the lowest energy arrangement of electron pairs in the molecule. Because repulsion involving lone pairs are stronger than bond pairs. Thus, F-Cl-F angle is a little less than 180°. Therefore, molecule has a T-shape geometry.
