Hexachloro-metallates: infrared, nuclear quadrupole resonance spectra, and X-ray structural studies

Author(s):  
P. J. Cresswell ◽  
J. E. Fergusson ◽  
B. R. Penfold ◽  
D. E. Scaife
1972 ◽  
Vol 25 (12) ◽  
pp. 2521 ◽  
Author(s):  
LPSPW Podmore

Preparative and structural studies on several series of vanadium(111) aqua chloro complexes and related compounds are reported. Results indicate that all compounds contain vanadium(111) in pseudo-octahedral coordination. Evidence is presented from electronic, infrared, and nuclear quadrupole resonance spectra, X-ray powder diffraction, and magnetic data. The compounds of empirical formulae VX3,6H2O (X = Cl, Br), RbVCl4,6H2O, and Cs2VX5,nH2O (X = Cl, n = 4; X = Br,n = 5) are all shown to contain the green trans-[V(OH2)4X2]+ ion. For compounds of formula AI2VCl5,H2O (A = Cs, Rb, K, NH4) prior methods of preparation are reexamined and a new method of preparation is given. Physical studies confirm that these compounds contain the red complex ion [V(OH2)Cl5I2-. The salts comprise structures of two types, one for A = Cs, the other for A = K, NH4, Rb; the latter salts are isostructural with K2FeCl5,H2O. The anhydrous compounds A12VCl5 (A = Cs, Rb) are also examined and the preparation of the rubidium salt is reported for the first time. For these compounds the magnetic results are interpreted in terms of a weak antiferromagnetic interaction in a proposed polymeric structure and this is supported by other evidence. Some data are reported for VBr3 and VI3.


1972 ◽  
Vol 25 (11) ◽  
pp. 2301 ◽  
Author(s):  
WJ Asker ◽  
DE Scaife ◽  
JA Watts

X-ray diffraction and halogen nuclear quadrupole resonance (n.q.r.) methods show that Rb3ZnBr5, (NH4)3ZnBr5, and CsZnI5 are isostructural with orthorhombic (NH4)3ZnCl5, and that Rb3ZnCl5 has the tetragonal Cs3CoCl5 structure. ZnI2,2NH3 is isomorphous with the corresponding chloride and bromide diammines. Rb2ZnBr4 and (NH4)2ZnBr4 have structures of Cs2ZnBr4 type, although the rubidium salt shows some stacking faults. In the complex chlorides 35Cl n.q.r. frequencies are grouped about 9 MHz, while the bromides have 81Br frequencies grouped around 60 MHz. The � → 3/2 transitions of 127I in the iodides are in the region of 76 MHz. The diammine compounds ZnBr2,2NH3 and ZnI2,2NH3 have frequencies close to the mean values for the ZnBr42- and ZnI42- ions respectively, but in the hydrates ZnCl2,l⅓H2O,ZnBr2,2H2O, β-KZnBr3,2H2O, and KZnI3,2H2O the halogen frequencies are increased. N.q.r. and X-ray data are also reported for the compound Cs3CuCl5, formed by quenching the melt. This compound slowly disproportionates at room temperature into Cs2CuCl4 and CsCl.


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