In aqueous solution Sn(H2O)64+ is the principal ionic species amongst a range of 6 coordinate ions with from 0-6 bromide ligands (e.g. Sn(H2O)64+, SnBr(H2O)53+) In basic solution the Sn(OH)62− ion is present.
SnBr4 forms 1:1 and 1:2 complexes with ligands, e.g. with trimethylphosphine the following can be produced, SnBr4.P(CH3)3 and SnBr4.2P(CH3)3.
SnBr4 crystallises in a monoclinic form with molecular SnBr4 units that have distorted tetrahedral geometry.
^Preparation, Infrared and Raman Spectra, and Stereochemistries of Pentacoordinate Trimethylphosphine Complexes, MX4•P(CH3)3 and MX4•P(CD3)3 where M = Ge or Sn and X = Cl or Br, Frieson D. K., Ozin G. A., Can. J. Chem. 51(16): 2697–2709 (1973) doi:10.1139/v73-406