Polyiodide amide complexes of transition metals: Structures and raman spectra

Assembling Polyiodides and Iodobismuthates Using a Template Effect of a Cyclic Diammonium Cation and Formation of a Low-Gap Hybrid Iodobismuthate with High Thermal Stability

“…The former is observed at 115 cm –1 and is supplemented by scarcely visible overtone satellites at about 230 and 340 cm –1 . It has a slightly higher Raman shift than normally observed for the triiodide anion (110 cm –1 ), [ 48 , 49 ] but that can be explained by a slightly shorter average I–I interatomic distance (2.92 Å) compared to what is typical for the I 3 – anion (2.94 Å) [ 50 ]. The band at 132 cm –1 should be attributed to the asymmetric stretch mode, which is typically observed in the range of 130–140 cm –1 .…”

Pattern of covalent and non‐covalent interactions within the pentaiodide anion in the structure of (3‐HOC5H9NH2)I5

“…The I1−I3 distance of 3.05 Å resembles a longer distance in various asymmetric triiodide anions, whereas the I3−I5 contact of 2.83 Å is typical for the shorter bond in a triiodide anion. The average I−I distance in the I1−I3−I5 unit is comparable with the expected range of 2.92–2.94 Å for I 3 − anions irrespective of their actual symmetry [15,31–33] . Analysis of the interatomic distances within the cis ‐chain makes it difficult to classify this pentaiodide as V‐shaped or L‐shaped.…”

“…À anions irrespective of their actual symmetry. [15,[31][32][33] Analysis of the interatomic distances within the cis-chain makes it difficult to classify this pentaiodide as V-shaped or L-shaped. Indeed, a V-shaped pentaiodide implies the (I À )(I 2 ) 2 formulation; however, the I1À I3 distance is too short to be considered as a separation between I À and I 2 , whereas the I3À I5 is too long to rationalize this pair of atoms as an I 2 molecule.…”

Hexakis(urea-O)iron Complex Salts as a Versatile Material Family: Overview of Their Properties and Applications

“…1,13−18,29−31,40−44 Deuteration resulted in an excellent tool to distinguish these bands from other vibrational modes due to the shifting of ND 2 modes to lower wavenumber, with ν(NH)/ν(ND) about 1.35. 17 The Raman spectra of the hexakis(urea)iron(III) tris-(diiodoiodate) salt (compound 12) 43 showed two intense (ν 2 and ν 3 ) and one weak (ν 1 ) Raman modes of the I 3 − ion at 147, 113, and 93 cm −1 . Since these anion bands are located in the far-IR range, the cation modes can be assigned easily without overlapping with anion modes.…”

“…Accordingly, the peak of the CO stretching mode gets shifted to a lower wavenumber, while the peak of the C–N mode is moved to a higher wavenumber compared to pure solid urea (Figure . ). ,− Most of the research reports used the ν(CO) and ν(C–N) modes to confirm the formation of hexakis(urea)iron complexes, since these modes have characteristic band positions for the complexes. − ,− In the case of hexakis(urea)iron(II/III) complexes, the ν(CO) symmetric stretching mode is expected between 1580 and 1500 cm –1 in the form of an intense peak (Figure ). ,− The ν(C–N) antisymmetric and symmetric stretching modes are expected between 1500 and 1450 cm –1 and 1050 and 1010 cm –1 , respectively.…”