The condensation of trinuclear rhenium bromide with lead sulfide yields the (H9O4)2Re6S6Br8 octahedral cluster complex isolated from the HBr/EtOH mixture in the form of the acid. (H9O4)2[Re6S6Br8] crystallizes in the P21/c space group, a = 9.2010(2) Å, b = 9.1508(2) Å, c = 17.3759(3) Å, γ = 101.817(1)°. Thermal decomposition of the complex at a moderate temperature (350 °C) results in a metastable Re6S6Br6 compound, which is not formed in the ternary Re–S–Br system at high temperatures. This compound is X-ray amorphous; its structure is determined based on the X-ray photoelectron and Raman spectroscopy data. [ABSTRACT FROM AUTHOR]