TY - JOUR
T1 - Synthesis and structure of bismuth(III)-containing noncentrosymmetric phosphates, Cs 3KBi 2M 4(PO 4) 6Cl (M = Mn, Fe). Monoclinic (Cc) and tetragonal (P4 3) polymorphs templated by chlorine-centered Cl(Bi 2Cs) acentric units
AU - West, J. Palmer
AU - Sulejmanovic, Dino
AU - Hwu, Shiou Jyh
AU - He, Jian
AU - Vanderveer, Don
AU - Johnson, B. Keith
PY - 2012/9/17
Y1 - 2012/9/17
N2 - Single crystals of three new noncentrosymmetric (NCS) phosphates, α (1) and β (2) forms of Cs 3KBi 2Mn 4(PO 4) 6Cl and α-Cs 3KBi 2Fe 4(PO 4) 6Cl (3), were grown in a reactive CsCl/KCl molten-salt media. Their structures were determined by single-crystal X-ray diffraction methods showing that the α form crystallizes in the space group Cc (No. 9), which is in one of the 10 NCS polar crystal classes, m (2/m) while the β form crystallizes in P4 3 (No. 78) of another polar class, 4 (4/m). The unit cell parameters of the α form can be approximately correlated with that of the β form via the 3 × 3 orientation matrix [0.5, 0.5, 0; -0.5, 0.5, 0; 0, 0, 2 sin β]. The structures of these otherwise complicated phosphates exhibit two types of channels with circular and elliptical windows where the Cl-centered Cl(Bi 2Cs) acentric unit is located. The neighboring acentric units are arranged in a parallel fashion in the α form, resulting in the monoclinic (Cc) lattice, but "antiparallel" in the β form, thus giving the tetragonal (P4 3) unit cell. 1-3 feature the compatible M-O-P unit that contains four crystallographically independent MO x (x = 4, 5) polyhedra, which are connected to the Cl(Bi 2Cs) acentric unit through one short and one long M II⋯Cl bond. The compositions of 1 and 2 consist of three Mn 2+ (d 5) and one Mn 3+ (d 4) per formula unit and that of 3 has three Fe 2+ (d 6) and one Fe 3+ (d 5). Bond valence sums reveal that, in the α phase, the trivalent site adopts distorted tetrahedral M(1) 3+O 4 coordination and, in the β phase, distorted trigonal-bipyramidal M(4) 3+O 5. Thus far, the iron phase has only been isolated in the α form presumably because of little extra stabilization energy gain if the Fe 2+ d 6 ion were to occupy the M(1)O 4 site. The possible origins pertaining to the structural differences in the α and β forms are discussed.
AB - Single crystals of three new noncentrosymmetric (NCS) phosphates, α (1) and β (2) forms of Cs 3KBi 2Mn 4(PO 4) 6Cl and α-Cs 3KBi 2Fe 4(PO 4) 6Cl (3), were grown in a reactive CsCl/KCl molten-salt media. Their structures were determined by single-crystal X-ray diffraction methods showing that the α form crystallizes in the space group Cc (No. 9), which is in one of the 10 NCS polar crystal classes, m (2/m) while the β form crystallizes in P4 3 (No. 78) of another polar class, 4 (4/m). The unit cell parameters of the α form can be approximately correlated with that of the β form via the 3 × 3 orientation matrix [0.5, 0.5, 0; -0.5, 0.5, 0; 0, 0, 2 sin β]. The structures of these otherwise complicated phosphates exhibit two types of channels with circular and elliptical windows where the Cl-centered Cl(Bi 2Cs) acentric unit is located. The neighboring acentric units are arranged in a parallel fashion in the α form, resulting in the monoclinic (Cc) lattice, but "antiparallel" in the β form, thus giving the tetragonal (P4 3) unit cell. 1-3 feature the compatible M-O-P unit that contains four crystallographically independent MO x (x = 4, 5) polyhedra, which are connected to the Cl(Bi 2Cs) acentric unit through one short and one long M II⋯Cl bond. The compositions of 1 and 2 consist of three Mn 2+ (d 5) and one Mn 3+ (d 4) per formula unit and that of 3 has three Fe 2+ (d 6) and one Fe 3+ (d 5). Bond valence sums reveal that, in the α phase, the trivalent site adopts distorted tetrahedral M(1) 3+O 4 coordination and, in the β phase, distorted trigonal-bipyramidal M(4) 3+O 5. Thus far, the iron phase has only been isolated in the α form presumably because of little extra stabilization energy gain if the Fe 2+ d 6 ion were to occupy the M(1)O 4 site. The possible origins pertaining to the structural differences in the α and β forms are discussed.
UR - http://www.scopus.com/inward/record.url?scp=84866361079&partnerID=8YFLogxK
U2 - 10.1021/ic3010129
DO - 10.1021/ic3010129
M3 - Article
AN - SCOPUS:84866361079
SN - 0020-1669
VL - 51
SP - 9723
EP - 9729
JO - Inorganic Chemistry
JF - Inorganic Chemistry
IS - 18
ER -