Beiträge zur Kristallchemie und zum thermischen Verhalten von wasserfreien Phosphaten. XXXIII [1] In2P2O7, ein Indium(I)‐diphosphato‐indat(III) und In4(P2O7)3 — Darstellung,Kristallisation und Kristallstrukturen |
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Authors: | H Thauern Robert Glaum |
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Abstract: | Contributions on Crystal Chemistry and Thermal Behaviour of Anhydrous Phosphates. XXXIII 1] In2P2O7 an Indium(I)‐diphosphatoindate(III), and In4(P2O7)3 — Synthesis, Crystallization, and Crystal Structure Solid state reactions via the gas phase lead to the new mixed‐valence indium(I, III)‐diphosphate In2P2O7. Colourless single crystals of In2P2O7 have been grown by isothermal heating of stoichiometric amounts of InPO4 and InP (800 °C; 7d) using iodine as mineralizer. The structure of In2P2O7 P21/c, a = 7.550(1) Å, b = 10.412(1) Å, c = 8.461(2) Å, b = 105.82(1)°, 2813 independent reflections, 101 parameter, R1 = 0.031, wR2 = 0.078] is the first example for an In+ cation in pure oxygen coordination. Observed distances d(InI‐O) are exceptionally long (dmin(InI‐O) = 2.82 Å) and support assumption of mainly s‐character for the lone‐pair at the In+ ion. Single crystals of In4(P2O7)3 were grown by chemical vapour transport experiments in a temperature gradient (1000 → 900 °C) using P/I mixtures as transport agent. In contrast to the isostructural diphosphates M4(P2O7)3 (M = V, Cr, Fe) monoclinic instead of orthorhombic symmetry has been found for In4(P2O7)3 P21/a, a = 13.248(3) Å, b = 9.758(1) Å, c = 13.442(2) Å, b = 108.94(1)°, 7221 independent reflexes, 281 parameter, R1 = 0.027, wR2 = 0.067]. |
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Keywords: | Indium Phosphates Crystal structure Lone‐pair effect |
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