No, that is not true. You should have been given the option to surrender you Praxair shares for Linde shares in what would have been a (mostly) non-taxable transaction. Form more information, see Material U.S. Federal Income Tax Considerations —Tax Consequences of the Merger to Holders of Praxair Shares” at https://www.sec.gov/Archives/edgar/data/1707925/000119312517254868/d283276ds4a.htm.
