Zusammenfassung
Two polymorphs of the borosulfate Cu[B-2(SO4)(4)] can be selectively prepared by solvothermal syntheses. The crystal structures of inosilicate-analogous alpha-Cu[B-2(SO4)(4)] (P1, no. 2, a = 5.2636(2), b = 7.1449(2), c = 7.9352(2) angstrom, alpha = 73.698(2)degrees, beta = 70.737(2)degrees, gamma = 86.677(2)degrees, 65 parameters, R-Bragg = 0.0052) and the new phyllosilicate-analogous polymorph ...
Zusammenfassung
Two polymorphs of the borosulfate Cu[B-2(SO4)(4)] can be selectively prepared by solvothermal syntheses. The crystal structures of inosilicate-analogous alpha-Cu[B-2(SO4)(4)] (P1, no. 2, a = 5.2636(2), b = 7.1449(2), c = 7.9352(2) angstrom, alpha = 73.698(2)degrees, beta = 70.737(2)degrees, gamma = 86.677(2)degrees, 65 parameters, R-Bragg = 0.0052) and the new phyllosilicate-analogous polymorph beta-Cu[B-2(SO4)(4)] (P2(1)/n, no. 14, a = 7.712(3), b = 8.149(3), c = 9.092(3) angstrom, beta = 111.22(1)degrees, 3829 independent reflections, 106 parameters, wR(2) = 0.054) are discussed. Further, the optical, magnetic and thermal properties of both polymorphs are investigated with focus on the role of the Cu2+ cation and its Jahn-Teller effect. The findings are confirmed by DFT calculations yielding insights in the stability of the synthesised polymorphs as well as a predicted gamma-modification. Additionally, the crystal structures of two polymorphs of copper hydrogensulfate Cu(HSO4)(2)-I (P2(1)/n, no. 14, a = 4.7530(2), b = 8.5325(4), c = 7.3719(3) angstrom, beta = 100.063(1)degrees, 1063 independent reflections, 55 parameters, wR(2) = 0.052) and Cu(HSO4)(2)-II (P1, no. 2, a = 4.79.88(8), b = 7.857(1), c = 8.057(1) angstrom, alpha = 77.86(1)degrees, beta = 87.02(1)degrees, gamma = 89.82(1)degrees, 1044 independent reflections, 109 parameters, wR(2) = 0.132) as well as that of Cu[S2O7] (C2/c, no. 15, a = 6.6341(4), b = 8.7302(5), c = 9.0555(8) angstrom, beta = 104.763(3)degrees, 1117 independent reflections, 48 parameters, wR(2) = 0.049) are presented and the cyclosilicate-analogous borosulfate Cu[B(SO4)(2)(HSO4)] is fully characterised with respect to its optical and thermal properties.