Reaction of the di-Grignard compound 1,3-(CIMgCH2)(2)C6H4 with HgCl2 yields 1,3-(ClHgCH2)(2)C6H4 (1), which crystallizes in the orthorhombic space group P2(1)2(1)2(1) with a = 8.494(1), b = 10.859(1), and c = 10.906(1) Angstrom, V = 1005.9(2) Angstrom(3), and Z = 4 (R values: R1 = 0.0354, wR2 = 0.0942). Treatment of 1 with InCl results in a transmetalation reaction and affords the tetrakis(tetrahydrofuran) adduct of 1,3-(Cl2InCH2)(2)C6H4 (2), which crystallizes in the monoclinic space group I2/a with a = 15.230(1), b = 13.125(1), and c = 15.299(1) Angstrom, beta = 92.14(1)degrees, V = 3056.0(4) Angstrom(3), and Z = 4 (R values: R1 = 0.0411, wR2 = 0.1003). As indicated by Hg-199 NMR spectroscopy, compound 1 does not form any stable anionic complexes in the presence of chlorides. In contrast, compound 2 readily complexes chloride anions. According to a VT H-1 NMR investigation, the species present in an equimolar mixture of 2 and Ph4PCI is the monoanionic complex [1-(Cl3InCH2)-3-((THF)(2)Cl2InCH2)C6H4](-) (3), whose structure is fluxional at room temperature. From this mixture, the salt [1,3-(Cl3InCH2)(2)C6H4](2-)[Ph4P+](2) (4) can been isolated by precipitation. Compound 4 crystallizes in the orthorhombic space group P2(1)2(1)2(1) with a = 14.632(1), b = 17.080(1), and c = 21.384(1) Angstrom, V = 5344.2(5) V-3, and Z = 4 (R values: R1 = 0.0346, wR2 = 0.0649).