Crystalline system Orthorhombic

White crystalline solid orthorhombic crystal density 1.769 g/cm at 20°C melts between 511 to 515°C (in a closed system) however, in an open system, it melts with decomposition at 280°C readily dissolves in water (solubility, 70.6 g and 104 g per 100 g water at 0°C and 100° C, respectively) insoluble in acetone, alcohol and ether. 

The PVC crystaUites are smaU, average 0.7 nm (3 monomer units), in the PVC chain direction, and are packed lateraUy to a somewhat greater extent (4.1 nm) (21,33). A model of the crystaUite is shown in Figure 6. The crystalline stmcture of PVC is found to be an orthorhombic system, made of syndiotactic stmctures, having two monomer units per unit cell and 1.44—1.53 specific gravity (34—37). 

Sulfates. Sulfate ions strongly complex zirconium, removing hydroxyl groups and forming anionic complexes. With increasing acidity, all hydroxyl groups are replaced zirconium sulfate [7446-31-3] Zr(S04)2-4H20, with an orthorhombic stmcture (206), can be crystallized from a 45% sulfuric acid solution. Zirconium sulfate forms various hydrates, and 13 different crystalline Zr(S0 2 5 2 [14644-61-2] systems are described in Reference 207. 

In the temperature range 193-278 K, the atoms in the BaTi03 crystal undergo further shifts, and the lattice symmetry is reduced to the orthorhombic system and C2v point group, as shown in Fig. 10.4.2(c). This crystalline modification has spontaneous polarization with ferroelectric properties. 

Porter, M. W. and Spiller, R. C. (1951). Crystals of the tetragonal, hexagonal, trigonal and orthorhombic systems. In The Barker index of crystals. A method for the identification of crystalline substances, Vol. 1, W. Heffer Sons, Cambridge. [14, 95] Porter, M. W. and Spiller, R. C. (1956). Crystals of monoclinic system. In The Barker index of crystals. A method for the identification of crystalline substances, Vol. 2, W. Heffer Sons, Cambridge. [14]... 

Only the hydrated oxides of cobalt(III) and nickel(IIl) are precipitated by alkali hypochlorites from cobalt(II) and nickel(II) solutions. Iron(III) hydroxide has two crystalline forms in the orthorhombic system, a-FeO(OH), dark brown needles, and y-FeO(OH), thin red plates. All other hydrates of Feg03 are mixtures of these with either FcgOg or absorbed water. 

Most organic compounds crystallize in the monoclinic or orthorhombic crystal systems, which contain substantial macroscopic anisotropies, and thus the singlecrystal CD technique cannot be applied, although our method of measurement may be useful if the macroscopic anisotropies are not very large. An alternative way to obtain crystalline-specific information is to examine the microcrystalline state. Measurements can be usually made either in nujol mull or KBr disc form, where microcrystals are dispersed randomly either in nujol or in a KBr microcrystalline matrix. The method was developed and applied to inorganic complexes by Mason [34], Bosnich [35], and Kuroda [9,10], and since then its application to metal complexes has been carried out sporadically [36,37]. Recently, the technique has become popular in the field of organic chemistry as well, probably stimulated by our work [38]. An alternative technique recently developed by us is diffuse reflectance CD (DRCD) which will be briefly described in V.B.2. 

In the crystalline state, the site symmetry is in general lower than the symmetry of the free molecule. The preferred lattice structures of sulfur homocycles are of the orthorhombic and monoclinic crystal systems. The molecular packing arrangements of the soKd allotropes are quite different In orthorhombic Si2, for example, the asymmetric unit is given by one quarter... 

Lithium hydroperoxide 1-hydrate is a white, crystalline compound, which belongs to the orthorhombic system (o = 7.92 A., b = 9.52 A., c — 3.20 A.).4 The calculated density with four molecules to the unit cell is 1.60.4 The measured density is 1.69. Additional water may be trapped mechanically to give compositions slightly above the 1-hydrate.4 The compound reacts spontaneously with atmospheric carbon dioxide to form lithium carbonate and release oxygen. It decomposes gradually on standing in a closed system at room temperature to lithium hydroxide 1-hydrate. 

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