Trihalides structures

The lanthanide trihalides structures are known to exhibit a high frequency of nine-coordinate-cation geometries (Karraker, 1970) but only recently has an... 

Several of the structure types found for the halides are observed for other important monovalent anion systems such as the trihydroxides and trihydrides and derivatives of these structures are observed for a variety of ternary phases (Haschke, 1975c and 1976b). Other monovalent anions, Y, are accommodated in PuBt3- and UCh-type RX3 phases by replacement of the X layers. The resulting RX2Y compositions are structural derivatives of the parent trihalide structures. These observations and the phase equilibria and crystal growth habits of the ternary derivatives support the conclusion that several of the trihalide structures are accurately described by alternation of RXj and X layers, but additional work is clearly necessary. 

The tetrafluorides have monoclinic (C2/c) UF4 (or Thp4)-type structures (Zachariasen, 1949 Larson et al., 1964), with twelve formula units per cell. The metals are eight coordinate and occupy slightly distorted antiprismatic sites. The structure may be described by alternation of RF " and R2F11 layers parallel to (100), but unlike the trihalide structures it does not appear to be a derivative of... 

Discrete molecules are apparent in the crystal structure of the higher trihalides of Sb, and,... 

All the trihalides are known to have 6-coordinate iridium (except the unknown structure of Irl3). IrF3 has the PdF3 structure a-IrCl3 and IrBr3 have structures of the A1C13 type (Ir—Cl 2.30-2.39 A in the former). 

The hydrolysis of 106 was studied in some detail and led to the isolation and structural characterization of a rare example of a titanoxane derivative with a planar Ti2(p-G)2 core 108 [111]. The formation of complex 108 can be contrasted with the hydrolysis reaction of the trihalides in the Cp and Cp series giving rise... 

Molybdenum hexafluoride. 3,1412 Molybdenum-iron-sulfur complexes, 4,241 Molybdenum oxide amino acid formation prebiotic systems, 6, 872 Molybdenum storage protein microorganisms, 6, 681 Molybdenum telluride, 3, 1431 Molybdenum tetraalkoxides physical properties, 2, 347 Molybdenum tribromide, 3,1330 Molybdenum trichloride, 3,1330 Molybdenum trifluoride, 3, 1330 Molybdenum trihalides, 3, 1330 bond lengths, 3, 1330 magnetic moments, 3,1330 preparation, 3,1330 properties, 3, 1330 structure, 3,1330 Molybdenum triiodide, 3,1330 Molybdenum trioxide complexes, 3, 1379 Molybdenum triselenide, 3, 143)... 

Wells et al. characterized group 13-stibine adducts by single crystal X-ray structure analyses first in 1997 [35]. The solid state structures of three borane-stibine adducts of the type X3B—Sb(Tms)3 (X = Cl 6, Br 7, I 8), obtained by reaction of boron trihalides BX3 and Sb(Tms)3 in n-pentane, were determined. 

Only some Lewis acid-base adducts of group 13 trialkyls R3M or trihalides CI3M and transition metal complexes of the type LnFe—E=CR2, (E = P, As) Weber L, Scheffer MH, Stammler HG, Stammler A (1999) Eur J Inorg Chem 1607 (LnW=P) Scheer M, Muller J, Baum G, Haser M (1998) J Chem Soc Chem Commun 1051, have been synthesized and structurally characterized... 

Although 1,3,2-diazaphospholenium cations are usually prepared from neutral NHPs or 1,3,2-diazaphospholes via Lewis-acid induced substituent abstraction or A-alkylation, respectively (cf. Sect. 3.1.2), the group of Cowley was the first to describe a direct conversion of a-diimines into cationic heterocycles by means of a reaction that can be described as capture of a P(I) cation by diazabutadiene via [4+1] cycloaddition [31] (Scheme 4). The P(I) moiety is either generated by reduction of phosphorus trihalides with tin dichloride in the presence of the diimine [31] or, even more simply, by spontaneous disproportionation of phosphorus triiodide in the presence of the diimine [32], The reaction is of particular value as it provides a straightforward access to annulated heterocyclic ring systems. Thus, the tricyclic structure of 11 is readily assembled by addition of a P(I) moiety to an acenaphthene-diimine [31], and the pyrido-annulated cationic NHP 12 is generated by action of appropriate... 

All these extended spoke adducts structurally resemble Z -shaped X82-polyhalides (X = I, Br) in which two asymmetric X3 trihalides are bridged by an X2 molecule.15 This further supports the above-mentioned similarity in the chemical nature of asymmetric X3 trihalides and linear E-X-Y systems in C.-T. adducts. 

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