Phenylantimony dichloride reacts with ionic chlorides such as Me 4NCl or HpyCl to give salts of both the [PhSbCl 3] − and [PhSbCl 4] 2− anions, whereas the related diphenylantimony chloride will accept only one chloride ion to give [Ph 2SbCl 2] − salts. Under similar conditions, no anionic products are formed from Ph 3Sb. These results can be rationalised if chloride ion addition takes place trans to antimonychlorine bonds in the starting material and the negative charge is delocalised via three-centre bonding in the resulting ClSb⋯Cl − system. Structures have been determined by single crystal X-ray diffraction for Me 4N[PhSbCl 3] ( a 9.214(5), b 11.499(5), c 16.179(6) Å, β 121.65(5)°, space group P2 1/ c), [Hpy] 2[PhSbCl 4] ( a 8.549(5), b 8.899(5), c 14.509(6) Å, α 100.16(5), β 90.09(4), γ 114.69(5)°, space group P 1 ) and Me 4N[Ph 2SbCl 2] ( a 12.255(5), b 11.078(5), c 14.200(6) Å, β 112.28(5)°, space group P2 1/ n). Me 4N[PhSbCl 3] contains a centrosymmetric, double chlorine-bridged dimeric anion, while the anions in both the [PhSbCl 4] − and [Ph 2SbCl 2] − salts are monomeric. Antimonychlorine bond distances are discussed in terms of the delocalisation picture mentioned above.