Recent Advances(tmp)
Tutton's salts(all are ratio of saturated solution mass, not solid mass or molar ratio) Zn:Co=9:1 is a nice pale red, different from the pink color of Mn2+, and extremely clear and well-formed. Ni:Co 9:1 Co3+-like cyan 8:2 dark green 7:3 nearly black. Such crystals show strong dichroism and also have different color in different directions. Diluting with Zn to Zn:Ni:Co=30:7:3 gives excellent crystals. Crystals containing Ni2+ are opaque, which depends on the concentration of Ni2+. At 50% still serious, 25% relatively acceptable and at 17.5%(see above) nearly negligible. Reason unknown. Ni2+ is symmetric(d8) but much smaller than Zn2+. Huge crystals of (NH4)3[VO2(C2O4)2].2H2O was grown, which is in fact very easy as long as saturated solution and seeds are obtained. Under protection Cr powder dissolves in H2SO4, yet no solid product was isolated. Addition of EtOH gives much powder of CrSO4.5H2O, light blue, yet oxidized very quickly into green stuff soluble in EtOH. Washing with EtO...