Alkali metal bismuth(III) chloride double salts

Evaporative co-crystallization of MCl (M = Na, K, Rb, Cs) with BiOCl in aqueous HCl produces double salts: MxBiyCl(x+3y)center dot zH(2)O. The sodium salt, Na2BiCl5 center dot 5H(2)O (monoclinic P2(1)/c, a = 8.6983(7) angstrom, b = 21.7779(17) angstrom, c = 7.1831(6) angstrom, beta = 103.0540(10)degrees, V = 1325.54(19) angstrom(3), Z = 4) is composed of zigzag chains of mu(2)-Cl-cis-linked (BiCl5)(n)(2n-) chains. Edge-sharing chains of NaCln(OH2)(6-n) octahedra (n = 0, 2, 3) are linked through mu(3)-Cl to Bi. The potassium salt, K7Bi3Cl16 (trigonal R-3c, a = 12.7053(9) angstrom, b = 12.7053(9) angstrom, c = 99.794(7) angstrom, V = 13,951(2) angstrom(3), Z = 18) contains (Bi2Cl10)(4-) edge-sharing dimers of octahedra and simple (BiCl6)(3-) octahedra. The K+ ions are 5- to 8-coordinate and the chlorides are 3-, 4-, or 5-coordinate. The rubidium salt, Rb3BiCl6 center dot 0.5H(2)O (orthorhombic Pnma, a = 12.6778(10) angstrom, b = 25.326(2) angstrom, c = 8.1498(7) angstrom, V = 2616.8(4) angstrom(3), Z = 8) contains (BiCl6)(3-) octahedra. The Rb+ ions are 6-, 8-, and 9-coordinate, and the chlorides are 4- or 5-coordinate. Two cesium salts were formed: Cs3BiCl6 (orthorhombic Pbcm, a = 8.2463(9) angstrom, b = 12.9980(15) angstrom, c = 26.481(3) angstrom, V = 2838.4(6) angstrom(3), Z = 8) being comprised of (BiCl6)(3-) octahedra, 8-coordinate Cs+, and 3-, 4-, and 5-coordinate Cl-. In Cs3Bi2Cl9 (orthorhombic Pnma, a = 18.4615(15) angstrom, b = 7.5752(6) angstrom, c = 13.0807(11) angstrom, V = 1818.87(11) angstrom(3), Z = 4) Bi octahedra are linked by mu(2)-bridged Cl into edge-sharing Bi-4 squares which form zigzag (Bi2Cl9)(n)(3n-) ladders. The 12-coordinate Cs+ ions bridge the ladders, and the Cl- ions are 5- and 6-coordinate. Four of the double salts are weakly photoluminescent at 78 K, each showing a series of three excitation peaks near 295, 340, and 380 nm and a broad emission near 440 nm. (C) 2016 Elsevier B.V. All rights reserved.