tani

I have read about extremely high solubility of SbCl3 in water several times, but I am having a hard time preparing a 2 millimolar solution of SbCl3 in water! I have tried heating it to 80C, stirring at room temperature for several days and also played around with pH a little bit, but the stubborn powder just does not seem to go into the solution. What am I doing wrong? Can someone help me out?