“…Zhu, Hor, and Otzschi also detailed different quinary oxysulfide families: (i) the Sr 2 Cu 2 MO 2 S 2 [M = Mn (Zhu and Hor, 1997a), Co (Zhu et al, 1997;Smura et al, 2011), Zn (Zhu and Hor, 1997a), Ni (Otzschi et al, 1999)] and Ba 2 Cu 2 CoO 2 S 2 (Zhu et al, 1997;Smura et al, 2011) family that displays an unusual square planar MO 2 layer and the two perovskite-based families (ii) Sr 3 Cu 2 M 2 O 5 S 2 [M = Sc (Otzschi et al, 1999), Fe (Zhu and Hor, 1997b)] and (iii) Sr 2 CuMO 3 S [M = Sc (Ogino et al, 2012), Cr (Zhu and Hor, 1997b), Fe (Zhu and Hor, 1997b), Ga (Zhu and Hor, 1997c), In (Zhu and Hor, 1997b)] with the work of Ogino on scandium. Later, Blandy transformed Sr 2 Cu 2 MnO 2 S 2 in Sr 2 Cu 1.5 MnO 2 S 2 by oxidative deintercalation of copper to obtain a mixed-valent perovskite (Blandy et al, 2015).…”