As your wife is a basic rate taxpayer, it is tax-efficient to transfer your holdings to her. The special dividend has not yet been paid and the record date, when your total registered shareholding is used to calculate the special dividend, has not been confirmed.
But for shareholders to qualify for the special dividend, they must hold shares from the record date to the merger date. Therefore, you risk not receiving the special dividend if you transfer the shares after the record date. If you transfer your shareholding to your wife after payment of the special dividend, she will be taxed at the dividend rate of 20 per cent.