No, but if the Trump team decided to sell the country in order to give favorable terms to a hostile state, by say, removing trade sanctions, releasing assets and capital, and/or sabotaging the possibility of an administration less willing to bend to said will, it could be treason.
"Treason against the United States shall consist only in levying war against them, or in adhering to their enemies, giving them aid and comfort. No person shall be convicted of treason unless on the testimony of two witnesses to the same overt act, or on confession in open Court. The Congress shall have power to declare the punishment of treason."
They could also get them on the Federal Election Campaign Act which prohibits taking contributions from foreign entities; this is generally monetary, but dirty laundry about the opponent has similar influencing effect.
Not to mention the whole Foreign Corrupt Practices Act, and the Racketeer Influenced and Corrupt Organizations Act, if the Trumps were taking dirty money or conducting business w/shady characters and w/prior knowledge before the election even started.
