CHM 124 Lecture 13: 13
Document Summary
Using curly arrows to show the movement of electron pairs. Curly arrows (and that"s exactly what they are called!) are used in mechanisms to show the various electron pairs moving around. You mustn"t use them for any other purpose. The arrow tail is where the electron pair starts from. That"s always fairly obvious, but you must show the electron pair either as a bond or, if it is a lone pair, as a pair of dots. Remember that a lone pair is a pair of electrons at the bonding level which isn"t currently being used to join on to anything else. The arrow head is where you want the electron pair to end up. For example, in the reaction between ethene and hydrogen bromide, one of the two bonds between the two carbon atoms breaks. That bond is simply a pair of electrons. Those electrons move to form a new bond with the hydrogen from the hbr.
