Structures of lead chlorite, magnesium chlorite hexahydrate and silver chlorite

Abstract

Pb(C102)2 (I), Mr = 340"9, orthorhombic, Ccca, a = 6.004 (1), b = 12.504 (2), c = 6.010 (1) A, V =451.2(1)A 3, z=4, Dx=5"O2Mgm -3, MoKal, h 0108-2701/90/101755-05503.00 = 0-70930 A, /z = 38-76 mm-~, F(000) = 592, T = 300 (1)K, final R = 0.030 for 502 observed unique reflections.Mg(C102)2.6H20 (II), Mr = 267"3,

Calcium chlorite, Ca(ClO2)2, from X-ray powder diffraction data

“…Satisfactory geometric parameters of the ClO 2 À anion (i.e. corresponding to those in other chlorites) were obtained through a weak restraint of the Cl-O distance to 1.57 (2) Å , which is the average value of the most accurate distances reported by Tarimci & Schempp (1975), Tarimci et al (1976), Pakkanen (1979), Castellani Bisi (1984), Okuda et al (1990), Marsh (1991), and Smolentsev & Naumov (2005a,b,c). At the same time, the O-Cl-O angle of 115.3 (3) is comparable to the average of 110 (2) found in the literature.…”

“…Ca(ClO 2 ) 2 is isostructural with Sr(ClO 2 ) 2 (Smolentsev & Naumov, 2005d) and Pb(ClO 2 ) 2 (Okuda et al, 1990). The experimental and calculated powder profiles, as well as the difference plot, are shown in Fig.…”

“…odd, hk0 with h or k odd, h0l with h or l odd, and 0kl with k or l odd, showed that the space group is Ccca (Ccce). Proceeding from this information, the Pb(ClO 2 ) 2 structure [Ccca (Ccce), Z = 4, a = 6.004 (1) Å , b = 12.504 (2) Å , c = 6.010 (1) Å ; Okuda et al, 1990] was chosen as a trial model for the full-profile Rietveld refinement. The Rietveld refinement was performed in two general steps.…”

Ammonium chlorite, NH4ClO2, at 150 K

“…3): 111.88 (12) versus 110.5 . Comparison can be made with other O-Cl-O angles in the literature: 110.0 (3) in LiClO 2 and 108.18 (18) in KClO 2 (Smolentsev & Naumov, 2005), 107.0 (1) in AgClO 2 (Okuda et al, 1990), 111.4 (1) in Zn(ClO 2 ) 2 Á2H 2 O (Pakkanen, 1979) and 112.5 (5) in Pb(ClO 2 ) 2 (Okuda et al, 1990). The present Cl-O bond distance [1.5759 (14) Å ] is close to the earlier value [1.57 (3) Å ] and compares well with the following literature values, in the same order as above: 1.578 (4), 1.565 (2), 1.575 (2), 1.580 (3) and 1.577 (9) Å .…”

Structure of magnesium chlorite hexahydrate. Corrigendum

“…Recently, Okuda, Ishihara, Yamanaka, Ohba & Saito (1990; hereafter OIYOS) carried out crystal structure determinations of Pb(ClO:)2 and Mg(CIOE)2.6H20 and an improved refinement of AgC1OE. For the magnesium compound they reported systematic absences (hkO with h + k odd, hhl with l odd) characteristic of space group P4Jnmc; however, they could not find a satisfactory solution in that space group (R = 0.066), and presumed that the first set of absences was only 'pseudo-systematic'.…”