Identification of a new family of phosphate compounds, A(I)B(6)(II)(P2O7)(2)P3O10: structures of KMn6(P2O7)(2)P3O10 and AgMn6(P2O7)(2)P3O10

Two members of a new family of inorganic phosphates of general formula A(I) B(II)(P2O7)(2)P3O10; KMn6(P2O7)(2)P3O10 (a = 5.405 (2), b = 26.918(l 1), c = 6.660(5), 107.31(3)', V = 925.1(9) A3, space group P21 Im, Z 2, Dc,lc = 3 A81 Mg M-3, R = 0.0377 for 2235 observed reflections) and AgMn6(P2O7)(2)P3O 10 (a = 5.424(7), b = 26.97(4), c = 6.627(9), beta = 106.81(7)degrees, V = 928(2) Angstrom (3), space group P2(1)/m, Z = 2, D-calc = 3.716 Mgm(-3), R = 0.0594 for 1577 observed reflections) have been synthesized and identifie d by single crystal X-ray diffraction. The isostructural complexes present an interesting comparison of silver and potassium bonding. (C) 2001 Edition s scientifiques et medicales Elsevier SAS. All rights reserved.