Synthesis, crystal structure and optical properties of a new lead fluoride borate with isolated [B9O21]15− unit

Borates: A Rich Source for Optical Materials

“… The FBBs with eight B atoms, such as, the 3D network of 3 [B 8 O 13 ] ∞ 8:∞ 3 [(5:4 Δ + T ) + (3:2 Δ + T )] built up by [B 8 O 16 ] FBBs in K 2 BaB 16 O 26 , the 3D framework of 3 [B 8 O 14 ] ∞ 8:∞ 3 [(5:3 Δ + 2 T ) + (3:2 Δ + T )] constructed by [B 8 O 17 ] FBBs in Na 2 B 4 O 7 , the 3D network of 3 [B 8 O 14 ] ∞ 8:∞ 3 [(4:5 Δ + 2 T ) + (3: Δ + 2 T ) + (1: Δ )] constructed by [B 8 O 17 ] FBBs in K 2 B 4 O 7 and Rb 2 B 4 O 7 , as well as the 3D network of 3 [B 8 O 14 ] ∞ 8:∞ 3 [(5:4 Δ + T )+(3: Δ + 2 T )] constructed by [B 8 O 17 ] FBBs in LiKB 4 O 7 and LiRbB 4 O 7 The FBBs with nine B atoms, such as, 0D [B 9 O 21 ] 9:[(3:3 T ) + 6­(1: Δ )] in Pb 8 (B 9 O 21 )­F, the 2D infinite layer of 2 [B 9 O 15 ] ∞ 9:∞ 2 [(5:4 Δ + T ) + (3:2 Δ + T ) + (1: T )] constructed by [B 9 O 19 ] FBBs in β-Na 2 B 6 O 10 , the 3D framework of 3 [B 9 O 15 ] ∞ 9:∞ 3 3­[(3:2 Δ + T )] built up by [B 9 O 19 ] FBBs in Na 2 Cs 2 BaB 18 O 30 and NaBaB 9 O 15 , as well as the 3D framework of 3 [B 9 O 15 ] ∞ 9:∞ 3 [(5:4 Δ + T ) + (4:2 Δ + 2 T )] built up by [B 9 O 19 ] FBBs in α-Na 2 B 6 O 10 The FBBs with ten B atoms, such as, 0D [B 10 O 21 ] 10:2­[(4:2 Δ + 2 T ) + (1: Δ )] in Pb 6 (B 10 O 21 ), the 2D infinite layer of 2 [B 10 O 21 ] ∞ 10:∞ 2 2­[(3: Δ + 2 T ) + (1: Δ ) + (1: T )] constructed by [B 10 O 24 ] FBBs in Pb 4 Zn 2 B 10 O 21 , the 2D infinite layer of 2 [B 10 O 17 ] ∞ 10:∞ 2 2­[(5:3 Δ + 2 T )] constructed by [B 10 O 21 ] FBBs in Cs 2 K 2 B 10 O 17 , as well as the 3D network of 3 [B 10 O 16 ] ∞ 10:∞ 3 2­[(5:4 Δ + T )] built up by [B 10 O 17 ] FBBs in δ-CsB 5 O 8 …”

“…The FBBs with nine B atoms, such as, 0D [B 9 O 21 ] 9:[(3:3 T ) + 6­(1: Δ )] in Pb 8 (B 9 O 21 )­F, the 2D infinite layer of 2 [B 9 O 15 ] ∞ 9:∞ 2 [(5:4 Δ + T ) + (3:2 Δ + T ) + (1: T )] constructed by [B 9 O 19 ] FBBs in β-Na 2 B 6 O 10 , the 3D framework of 3 [B 9 O 15 ] ∞ 9:∞ 3 3­[(3:2 Δ + T )] built up by [B 9 O 19 ] FBBs in Na 2 Cs 2 BaB 18 O 30 and NaBaB 9 O 15 , as well as the 3D framework of 3 [B 9 O 15 ] ∞ 9:∞ 3 [(5:4 Δ + T ) + (4:2 Δ + 2 T )] built up by [B 9 O 19 ] FBBs in α-Na 2 B 6 O 10 …”

“…Several highly polymerized B–O/F clusters are formed by the condensation of mono -, di -, tri -, tetra -, and penta -groups consisting of different numbers of B–O/F polyhedra, but the high polymerized B–O/F clusters are seldom observed experimentally and less than 3.0% borates are found to possess such units. Several B–O clusters, however, have been found in isolated form with the high polymerization degree ( n > 6), such as, [B 6 O 12 ], [B 6 O 16 ], [B 7 O 14 ], [B 9 O 21 ], [B 10 O 21 ], [B 11 O 22 ], [B 12 O 24 ], and [B 18 O 36 ] units (Figure and Table S1 in the SI). − ,,,− …”

“…To date, the isolated [B 7 O 14 ] unit constructed by three continuous linked rings is rare in borates and only found in ABa 7 Mg 2 B 14 O 28 F 5 (A = Na, K) , with atomic disorder and disorder-free Li 4 Cs 3 B 7 O 14 . The three compounds, Pb 8 (B 9 O 21 )­F, Pb 6 B 10 O 21 , and Li 6 Rb 5 (B 11 O 22 ), are the sole examples of the [B 9 O 21 ], [B 10 O 21 ], and [B 11 O 22 ] clusters, respectively. The [B 9 O 21 ] cluster is composed of a central [B 3 O 9 ] unit and six [BO 3 ] triangles interlined by sharing terminal O atoms.…”

Identical in Formula but Not Isotypic in Configuration: Discovery of a New Highly Polymerized [B12O24] Cluster in Cs3AlB6O12

“…), in which the cations with a higher valence state can form rigid chemical bonds (M–O/F) and break the anionic framework into a 0D configuration because of their stronger coordination ability. , Among them, the low polymerization degree of isolated B m –O/F ( m < 6) groups, like [BO 2 ], [BO 3 ], [BO 4 ], [B 2 O 5 ], [B 3 O 6 ], and [B 5 O 10 ] units, is much more than that of the highly polymerized ones (∼97 vs 3%). ,− To date, the [B 18 O 36 ] cluster is the largest one in the anhydrous borates and is found in Sr 8 MB 18 O 36 (M = Mg, Zn, Cd) , and NaSr 7 AlB 18 O 36 series . Other highly polymerized 0D clusters B m -O/F ( m ≥ 6), like [B 6 O n ] ( n = 12, 14), [B 7 O 14 ], [B 9 O 21 ], [B 11 O 22 ], [B 12 O 24 ] units, etc., are also very limited and have only been discovered in few borates. − Studies have shown that the highly polymerized B–O clusters tend to form the same and certain configurations, like [B 12 O 24 ] and [B 18 O 36 ] units, in related compounds and are all in a cyclic formation constructed by [B 3 O 7 ] and [B 3 O 8 ] branches with an end-to-end model, and both types show identical formulas and structures. − ,, Of course, the discovery of such borates greatly enriched the structural chemistry of the borate system.…”