Cadmium iodide

Titanium Dibromide. Titanium dibromide [13873-04-5] a black crystalline soHd, density 4310 kg/m, mp 1025°C, has a cadmium iodide-type stmcture and is readily oxidized to trivalent titanium by water. Spontaneously flammable in air (142), it can be prepared by direct synthesis from the elements, by reaction of the tetrabromide with titanium, or by thermal decomposition of titanium tribromide. This last reaction must be carried out either at or below 400°C, because at higher temperatures the dibromide itself disproportionates. 

Titanium Dhodide. Titanium diiodide is a black soHd p = 499(0) kg/m ) that has the cadmium iodide stmcture. Titaniums occupy octahedral sites in hexagonaHy close-packed iodine layers, where a = 411 pm and c = 682 pm (144). Magnetic studies indicate extensive Ti—Ti bonding. Til2 reacts rapidly with water to form a solution of titanous iodide, Til. ... 

Cadmium Iodide. Two crystal morphologies exist for Cdl2 [7790-80-9] the white a-form (see Table 1) and the brown p-form. The latter... 

Figure 15.18 Comparison of the nickel arsenide structure (a) adopted by many monosulfides MS with the cadmium iodide structure (b) adopted by some disulfides MS2. The structures are related simply by removing alternate layers of M from MS to give MS2.

Kadmium-jodid. n. cadmium iodide, -legie-rung. /. cadniium alloy, -oxydhydrat, n. cadmium hydroxide. 

Prepared in situ by treatment of methylmagnesium bromide (4equiv) with cadmium iodide (2equiv). d 5% unrcactcd ketone recovered. 

The addition reaction requires the presence of 4 equivalents of HMPA, thus partial racemization of optically active aldehydes under these basic conditions is anticipated. Unfortunately, the addition of magnesium bromide, zinc chloride or cadmium iodide reverses the regioselectivity11 ... 

The addition of anhydrous cadmium iodide or chloride on allylic lithium carbanions causes changes in the regioselectivity, but information on the stereochemical results is scarce31-42-43. 

In other crystals an octahedral metal atom is attached to six non-metal atoms, each of which forms one, two, or three, rather than four, bonds with other atoms. The interatomic distance in such a crystal should be equal to the sum of the octahedral radius of the metal atom and the normal-valence radius (Table VI) of the non-metal atom. This is found to be true for many crystals with the potassium chlorostannate (H 61) and cadmium iodide (C 6) structures (Table XIB). Data are included in Table XIC for crystals in which a tetrahedral atom is bonded to a non-metal atom with two or three covalent bonds. The values of dcalc are obtained by adding the tetrahedral radius for the former to the normal-valence radius for the latter atom. 

Molybdenite was the first substance found to contain a trigonal prism as ligation polyhedron for ligancy 6, instead of the more common octahedron (Dickinson and Pauling, 1923). An acceptable explanation of the stability of the molybdenite structure, rather than the cadmium iodide... 

Cdli Cadmium iodide InClj POCIa VOCI3 Pda RhCla... 

The nickel arsenide type (NiAs) is the result of linking layers of the kind as in cadmium iodide. Continuous strands of face-sharing octahedra perpendicular to the layers... 

Schnepfe [83] has described yet another procedure for the determination of iodate and total iodine in seawater. To determine total iodine 1 ml of 1% aqueous sulfamic acid is added to 10 ml seawater which, if necessary, is filtered and then adjusted to a pH of less than 2.0. After 15 min, 1 ml sodium hydroxide (0.1 M) and 0.5 ml potassium permanganate (0.1M) are added and the mixture heated on a steam bath for one hour. The cooled solution is filtered and the residue washed. The filtrate and washings are diluted to 16 ml and 1ml of a phosphate solution (0.25 M) added (containing 0.3 xg iodine as iodate per ml) at 0 °C. Then 0.7 ml ferrous chloride (0.1 M) in 0.2% v/v sulfuric acid, 5 ml aqueous sulfuric acid (10%) - phosphoric acid (1 1) are added at 0 °C followed by 2 ml starch-cadmium iodide reagent. The solution is diluted to 25 ml and after 10-15 min the extinction of the starch-iodine complex is measured in a -5 cm cell. To determine iodate the same procedure is followed as is described previously except that the oxidation stage with sodium hydroxide - potassium permanganate is omitted and only 0.2 ml ferrous chloride solution is added. A potassium iodate standard was used in both methods. 

Diethylcadmium is prepared in turn by the reaction of cadmium iodide with triethylaluminum. 

Figure 3.18 Cadmium iodide, Cdl2, structure (a) perspective view of the structure as layers of Cdlg octahedra (b) one layer of the structure, with the lower I- anion (A) layer and the middle Cd2+ (c) layer shown complete and just three anions of the upper (B) layer indicated. The vector b represents the Burgers vector of one of three unit dislocations and bl and b2 represent the Burgers vectors of the two equivalent partial dislocations. The unit cell dimensions are a, b, and c.

Cadmium Iodide (ideal), Cdl2, Cadmium Hydroxide, Cd(0H)2... 

Procedure Shake 10 ml of chloroform with 20 ml of freshly boiled and cooled DW for 3 minutes and allow to separate. To the aqueous layer add 1 ml cadmium iodide soln. and 0.1 ml of 10 ml of starch mucilage. Prescribed Limit No blue colour is produced. 

CdI2 CADMIUM IODIDE -899.5410 3.5567E+04 3.3430E+02 -1.6865E-01 3.2257E... 

---