A rational synthesis of new anion [HgBr4Cl]3−: Synthesis, characterization and single crystal X-ray structure determination of [Co(NH3)6][HgBr4Cl]

“Caging” Anions through Crystal Engineering to Avoid Polymerization: Structural, Conformational and Theoretical Investigations of New Halocadmate [Cd2X7]3– Anions (X = Cl/Br)

“…However, when the calculations were carried out in a simulated aqueous environment, the calculated conformations become comparable to those found in the crystals, as shown in Figure 6 where the optimized geometry of [Cd 2 Cl 7 ] 3-is reported together with the bond lengths and angles obtained for [Cd 2 Br 7 ] 3-(bottom values). By using the same level of theory, geometry optimization calculations were repeated on the Hg 2 Cl 7 3-anion and similar results were obtained: in vacuo the Hg-Cl-Hg angle is close to 180°(174.6°), while in an aqueous environment the angle becomes 102.9°. At first sight, it seems that in a polar environment the "angular" geometry is preferred to the "linear" one mainly for two reasons: (i) there is a gain in solvation energy due to the exposure of the central chloride to the solvent and (ii) the volume of the cavity, which is formed to accommodate the solute molecule, is smaller.…”

“…Moreover, Table 2 data reveals that halodicadmate fragments are present in polymeric structures. The tendency to form a polymeric structure is present in analogous complexes with Hg as the central atom, although there are few structures with isolated Hg 2 X 7 3-(X = halogen, six structures). [13] Besides these compounds, only two other struc- [a] The list of the CSD ref codes is available in the Supporting Information (see Table S1).…”

“…Recently, the role of topology and the hydrogen bonding capabilities of a large counterion, [Co(NH 3 ) 6 ] 3+ , have been shown in the isolation of new anionic species such as [Hg 2 (SCN) 7 ] 3-and [HgBr 5 ] 3-by our group [2] and the isolation of [Cu 4 (OH)(CO 3 ) 8 ] 9-by Robson and coworkers. [3] These studies indicate that the compatibility in size and topology of counteranions is important in the lattice stabilization along with complementarity in the second sphere interactions.…”

Synthesis, characterization and X-ray structural studies of three hybrid inorganic–organic compounds: Silver(I)-, lead(II)- and tris(phenanthroline)copper(II)- 2,6-naphthalenedisulfonate (2,6-nds)

“…By using ion exchange strategy, we have successfully isolated and structurally characterized hitherto unknown anions: [Hg 2 (SCN) 7 ] 3- [13], [HgBr 5 ] 3- [14], [HgBr 4 Cl] 3- [15], [CdBr 4 Cl 2 ] 4- [16], [CdBr 4 benzoate] 3- [17] and [Cd 2 X 7 ] 3- [18] with appropriate large cation i.e. cationic metal complex.…”