Ternary and tetrahedral symmetry in hybrid fluorides, fluoride carbonates and carbonates

Two tantalum fluorides templated with tren: [H4tren](TaF7)2·H2O and [H4tren](TaF7)2

“…The ''scorpion'' conformation of [H 4 tren] 4+ cations leads to characteristic N p -N t distances between primary and tertiary amine groups (Table 1): 0, 1 or 2 short distances plus 3, 2 or 1 long distances; N p -N t distances vary between 3.18 and 3.83 Å . These geometrical features were recently observed in several fluoroaluminates [7][8][9] and fluorozirconates [5].…”

Hydrogen bonded H3O+, H2O, HF, F− in fluoride metalates (Al, Cr, Fe, Zr, Ta) templated with tren (tris-(2-aminoethyl)amine)

“…3): a ''spider'' shape with N p -N t -N p angles smaller than %958 or larger than %1008 and a ''scorpion'' shape with two (or three) N p -N t distances shorter than %3.2 Å or longer than %3. 3 5 ] species [13]; none of two possible cagelike forms is octahedral. …”

“…Numerous fluorides crystallise when tren amine (tris-(2-aminoethyl)amine) reacts with metal oxides, hydroxides or fluorides and aqueous HF in solvothermal conditions at low temperature [1][2][3][4][5][6][7][8]. According to the HF aqÁ content, the amine is tri-or tetra-protonated and the corresponding [H 3 associated entities is discussed in the article, together with the thermal stability of the solids.…”

The first crystallographic example of a face-sharing fluoroaluminate anion Al2F93−

“…15 The simplest form of a fluoroaluminate anion based on the octahedral AlF 6 unit is AlF 6 3− and larger isolated species. [16][17][18][19][20][21][22][23][24][25][26] In a few rare cases, edge-sharing bioctahedral motifs were observed in dinuclear, 8,27,28 chain-like 7,29,30 and layered 31,32 structures. One of the cases missing from this series is the face-sharing structure of the bioctahedral Al 2 F 9 3− anion.…”