Iodine chloride Crystal structure

Since the Braggs first determination, thousands of structures, most of them far more complicated than that of sodium chloride, have been determined by x-ray diffraction. For covalently bonded low molecular weight species (such as benzene, iodine, or stannic chloride), it is often of interest to see just how the discrete molecules are packed together in the crystalline state, but the crystal structures affect the chemistry of such substances only to a minor degree. However, for most predominantly ionic compounds, for metals, and for a large number of substances in which atoms are covalently bound into chains, sheets, or three dimensional networks, their chemistry is very largely determined by the structure of the solid. 

An -ray crystal structure of the diarsine complex (8), prepared by the reaction of iodine in methylene chloride with the corresponding complex (L-L)W(CX> 4, shows the seven-co-ordinate tungsten as a distorted capped octahedron , one of the CO ligands forming the cap, and the CsAssW ring being puckered. 

The mixed halide structure, for which the composition was refined to [(Zr6B)Clii.47(2)ll,, 53], crystallizes in the tetragonal space group P42/mnm, contrary to the only-chloride parent-type, which crystallizes orthorhombically [17]. This increase of symmetry is achieved through a random iodine substitution of 19.1(3)% of the Cl4 -site. Thereby the Zr3CF -units become planar, as can be seen from Fig. 5.5. 

Copper (I) iodide is a dense, pure white solid, crystallizing with a zinc-blende structure below 300°. It is less sensitive to light than either the chloride or bromide, although passage of air over the solid at room temperature in daylight for 3 hours results in the liberation of a small amount of iodine. It melts at 588°, boils at 1,293°, and unlike the other copper halides, is not associated in the vapor state. Being extremely insoluble (0.00042 g./l. at 25°), it is not perceptibly decomposed by water. It is insoluble in dilute acids, but dissolves in aqueous solutions of ammonia, potassium iodide, potassium cyanide, and sodium thiosulfate. It is decomposed by concentrated sulfuric and nitric acids. 

Das and Rout claim to have prepared the imino forms (143) of several 2-toluidino-l,3,4-thiadiazoles (145) by oxidation of the corresponding 4-tolylthiose micarbazones (144) with iodine or potassium ferricyanide in alkaline solution. Later, Ramachander and Srinivasan repeated this synthesis in similar systems, but they also prepared the tautomers (145) by oxidation of 144 with ferric chloride. It is highly unlikely that individual tautomers like 143 and 145 should exist as separate compounds, particularly as they have crystallized from the same solvent, ethanol. The only proofs for the structure 143 are sulfur analyses, but it is evident from the melting points that 143 is identical neither with 145 nor with the isomeric triazolinethiones. Menin et al. tried to repeat the preparation of 143, though without success. 

The dimeric mono(cyclooctatetraenyl)lanthanide chlorides [(COT)Ln(/r-Cl)(THF)2]2 are long known and still represent the most useful precursors in (COT)Ln chemistry. A recently reported alternative preparation of the Sm derivative involves the reaction of samarium metal with COT in THF in the presence of a small amount of I IgCL. The molecular structure of [(COT)Sm(/i-CI)(TT 11 )2]2 has been determined.805,806 Iodo-(cyclooctatetraenyl)lanthanide iodides of the type (COT)Lnl(TIIF) (Ln = La, Ce, Pr, n = 3 Ln = Nd, n = 2 Ln = Sm, n l) are readily accessible in a one-pot reaction of metallic lanthanides with COT in the presence of an equimolar amount of iodine. Bromo- and chloro-bridged binuclear complexes of samarium, [(COT)Sm(/.t-X)(THF )2]2 (X = Br, Cl), were also prepared by the reaction of samarium metal with COT in the presence of 1,2-dibromoethane or Ph3PCl2, respectively.807 Alternatively, the iodo complexes (COT)LnI(THF)3 (Ln = Nd, Sm) can be synthesized directly from the lanthanide triiodides and K2COT. The molecular structure of (COT)Ndl(THF)3 has been determined by X-ray diffraction.808 A clean preparation of the monomeric half-sandwich complex (GOT)TmI(THF)2 involves treatment of Tml2 with equimolar amounts of COT in THF at room temperature (Scheme 227). The product was isolated as red crystals in 75% yield.628... 

Halobenziodoxoles l-Chloro-l,2-benziodoxol-3-(l//)-one (88, 2X = O, Y = Cl) can be easily prepared by direct chlorination of 2-iodobenzoic acid [233], or by the oxidation of 2-iodobenzoic acid with sodium chlorite (NaC102) in aqueous hydrochloric acid media [267]. The original X-ray single-crystal analysis of l-chloro-l,2-benziodoxol-3-(l//)-one reported in 1976 was relatively imprecise [268]. More recently, Koser and coworkers reported the single-crystal X-ray structure of a 1 1 complex of l-chloro-1,2-benziodoxol-3-(l/7)-one and tetra-n-butylammonium chloride [262], The primary bond distances at iodine in this compound are consistent with expectations for a X -iodane. In particular, the I—Cl and I—O bond distances of 2.454 and 2.145 A, respectively, are greater than the sums of the appropriate covalent radii and reflect the... 

Single-crystal X-ray structures have been reported for the following aryl- and heteroaryliodo-nium salts diphenyliodonium triiodide [412], (2-methylphenyl)(2-methoxyphenyl)iodonium chloride [413], (2-methoxy-5-methylphenyl)(4-methoxy-2-methylphenyl)iodonium trifluoroacetate [414], (2-methoxy-5-methylphenyl)(4-methoxyphenyl)iodonium trifluoroacetate [415], a complex of diphenyliodonium tetrafluoroborate with pyridine [416], a complex of diphenyliodonium tetrafluoroborate with 1,10-phenanthroline [417], a complex of diphenyliodonium tetrafluoroborate with 18-crown-6 [418], 1-naphthylphenyliodonium tetrafluoroborate [419], 3,10-dimethyl-10//-dibenzo[, e]iodinium tetrafluoroborate [420], aryl(pentafluorophenyl)iodonium tetrafluoroborates [421], 4,4 -[bis(phenyliodonium)]-diphenylmethane ditriflate [422], [bis(4-methoxyphenyl)](diethylaminocarbodithioato)iodine(in) [423], di(p-tolyl)iodonium bromide [424], diphenyliodonium chloride, bromide and iodide [425,426], diphenyliodonium nitrate [427], diphenyliodonium tetrafluoroborate [428], thienyl(phenyl)iodonium salts [401], (anft-dimethanoanthracenyl)phenyliodonium tosylate and hexafluorophosphate [429] and 3-mesityl-5-phenylisoxazol-4-yl(phenyl)iodonium p-toluenesulfonate [409]. 

X-Ray structural analysis of the co-crystal of p-34 with tri(dimethylamino) cyclopropenium chloride showed several halogen bonds to the halide. Most importantly, a bidentate coordination to chloride is observed for (me side of the halogen-bond donor. As this induces a slight distortion of the central aiyl backbone, the distance between the iodine atoms on the other side of the XB donor is elcmgated, and two monodentate halogen-bonds to chloride are found on this side (Fig. 13). 

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