Hydrothermal Synthesis and Characterization of an Ethylenediamine-Templated Mixed-Valence Titanium Phosphate

Abstract

The mixed-valence compound Ti III Ti IV (HPO 4 ) 4 ‚C 2 N 2 H 9 ‚H 2 O (1) is synthesized hydrothermally from titanium powder, phosphoric and boric acids, and ethylenediamine. The compound is structurally stable up to 650 °C. It loses the template and the water molecule above 250 °C, all titanium becomes Ti IV at 600 °C, and the result is the new compound Ti IV Ti IV (HPO 4 ) 4 (2). The structures of the two compounds were determined ab initio from powder diffraction data. Crystal data: Ti III Ti IV (HPO 4 ) 4 ‚C 2 N 2 H 9 ‚H 2 O, I4 1 , a ) 6.371(2), c ) 16.571(1) Å, V ) 672.5(1) Å 3 , Z ) 2; Ti IV Ti IV (HPO 4 ) 4, I4 1 /a, a ) 6.335(2), c ) 16.389(1) Å, V ) 657.7(1) Å 3 , Z ) 2. Both structures are of the open type, and the frameworks are nearly identical. Compound 2, τ-Ti(HPO 4 ) 2 , is the first three-dimensional titanium hydrogen phosphate. Results of magnetization, TGA, BET, X-ray thermodiffractometry, and density measurements are also presented.

Hydrothermal Synthesis and Crystal Structure of Na2In2[PO3(OH)]4·H2O with a New Structure Type

“…Ti'4Ti'4(HPO ) (23). In these structures, eight-membered rings can also be identi"ed and the condensations are similar to those of the indium compound, except that in the titanium phosphate structures, there are disorders in the phosphate groups that make the structure lack channels.…”

Bismuth oxychloride modified titanium phosphate nanoplates: A new p-n type heterostructured photocatalyst with high activity for the degradation of different kinds of organic pollutants

“…Recently, phosphate based composite materials become one of research hotspots because of their special open framework structure [4]. Especially, the n-type titanium phosphate has received extensive attentions because of its high photooxidation and photoreduction capability, non-toxicity, good chemical stability, and low fabrication cost [5][6][7][8][9][10][11][12][13]. However, easy recombination of photoinduced electron-hole pairs still existing in the photocatalysis process of titanium phosphate, which leads to its low quantum yields [14].…”

Offene Gerüststrukturen von Übergangsmetallen

“…In [C 2 N 2 H 10 ] 0.5 [Sc(HPO 4 ) 2 ] sind streng abwechselnde ScO 6 ‐ und HPO 4 ‐Polyedereinheiten zu einer dreidimensionalen Struktur verknüpft 73a. Das gemischtvalente [C 2 N 2 H 9 ][Ti III Ti IV (HPO 4 ) 4 ]⋅H 2 O enthält eindimensionale Ketten, die durch die Verknüpfung von (Ti III /Ti IV )O 6 ‐Oktaedern mit HPO 4 ‐Tetraedern gebildet werden 74b. Diese Ketten sind durch weitere HPO 4 ‐Tetraeder zu Schichten verbunden, die wiederum zu einer dreidimensionalen Struktur verknüpft sind.…”