Correlation of structure and triboluminescence for tetrahedral manganese(II) compounds

To investigate the structural basis of triboluminescence, several known tetrahedrally coordinated Mn(II) complexes have been synthesized according to literature methods and their crystal structures have been determined by X-ray diffraction. Among them, (MePh(3)P)(2)[MnCl(4)] (2), a = 15.4804(4) A, cubic, space group P2(1)3, Z = 4; (Et(4)N)(2)[MnBr(4)] (4), a = 13.362(1) A, c = 14.411(1) A, tetragonal, space group P42(1)m, Z = 4; MnBr(2)(OPPh(3))(2) (7), a = 9.974(1) A, b = 10.191(3) A, c = 10.538(2) A, alpha = 65.32(1) degrees, beta = 63.49(1) degrees, gamma = 89.44(2) degrees, triclinic, space group P1, Z = 1; and MnBr(2)(OAsPh(3))(2) (10), a = 17.816(3) A, b = 10.164(1) A, c = 18.807(3) A, orthorhombic, space group Pca2(1), Z = 4 were reported to be triboluminescent and (Me(4)N)(2)[MnCl(4)] (3), a = 9.016(3) A, b = 36.90(2) A, c = 15.495(3) A, beta = 90.72(3) degrees, monoclinic, space group P2(1)/n, Z = 12, and MnI(2)(OAsPh(3))(2) (11), a = 10.094(4) A, b = 10.439(2) A, c = 34.852(2) A, alpha = 83.17(4) degrees, beta = 86.09(2) degrees, gamma = 75.16(3) degrees, triclinic, space group P1, Z = 4, were reported to be not triboluminescent. The result supports the correlation between space group acentricity and triboluminescence activity.