The solid-state hierarchy and iodination potential of [bis(3-acetaminopyridine)iodine(i)]PF₆

Abstract

The first iodine(I) complex bearing hydrogen-bond donor and acceptor groups, [bis(3-acetaminopyridine)iodine(I)]PF6 (3), was synthesised and demonstrated two temperature-dependent solid-state connectivities of the hydrogen bonding. Upon reaction of 3 with tBuOMe,...

Chiral carbonyl hypoiodites

“…Interestingly, this is contrary to the general trend observed for [N-I-N] + complexes where the I + complexes experience a downfield shift of their 1 H NMR peaks compared to their respective free ligands and linear [N-Ag-N] + precursor complexes. 8,33 The 1 H- 15 N HMBC studies in CD 2 Cl 2 were used to determine the 15 N NMR chemical shifts of the pyridinic nitrogen atoms, with those being aptly positioned to reflect the characteristic iodine(I) to nitrogen interaction upon complexation. The 15 21 Whilst the phthalimido 15 N NMR chemical shifts were observed in high concentration samples of 1 (À219.4 ppm) and 2 (À212.9 ppm), the phthalimido 15 N NMR peaks were not observed for 3a-3c, which not surprising given that the HMBC parameters were optimised for the more informative pyridinebased ligands, and with the possibility of the much weaker Scheme 1 The reaction protocols used to synthesis the hypoiodite compounds (3a-3c) in three steps starting from commercially available (S)-valine.…”

“…Interestingly, this is contrary to the general trend observed for [N–I–N] + complexes where the I + complexes experience a downfield shift of their 1 H NMR peaks compared to their respective free ligands and linear [N–Ag–N] + precursor complexes. 8,33…”

Solid‐state NMR Spectroscopy of Iodine(I) Complexes

“…In recent years, the field of halogen(I) chemistry has seen a myriad of advancements, with the observation of the first structurally chiral, [18] unrestrained heteroleptic, [38] hierarchical, [39] and nucleophilic iodine(I) interaction complexes being reported in the solid state. [40][41][42] This progress had led to a recent infusion of liquid state 1 H and 15 N NMR data, however, it has also revealed dynamic behavior, such as ligand scrambling, especially for unrestrained heteroleptic halogen(I) complexes.…”

Halogen-Bonded [N–I–N]− Complexes with Symmetric or Asymmetric Three-Center–Four-Electron Bonds

“…26 Erdeĺyi 27−32 has demonstrated with very precise and comprehensive studies in solution, supplemented with computational calculations, that the [N−I−N] + halogen bond has a very strong interaction ratio R XB < 0.65 (R XB defined as the sum of the vdW radii of the interacting atoms divided by their contact distance), as well as being linear and symmetric with the iodine atom located in the center between the N atoms with a very small N−I distance variation. Over the last 5 years the field of halogen(I) chemistry has expanded greatly, with recent developments including the first iodine(I)based capsules, 33−36 helicates, 37 asymmetric complexes, 38,39 halogen-bonded organic frameworks (XOF), 40 halogenbonded hierarchical materials, 41 and solid-state nucleophilic I + •••Ag + interactions. 42−44 In addition to the aforementioned positively charged XB complexes, the almost nearly as strong (R XB = 0.65−0.67) but neutral N−I•••N and N−I•••O−N XB complexes, which are easily prepared from suitable haloimides and halosulfonimides as the XB donors and pyridine derivatives or pyridine N-oxides as the XB acceptors, have been extensively studied by Fourmigué4 5,46 and us.…”

“…Erdélyi − has demonstrated with very precise and comprehensive studies in solution, supplemented with computational calculations, that the [N–I–N] + halogen bond has a very strong interaction ratio R XB < 0.65 ( R XB defined as the sum of the vdW radii of the interacting atoms divided by their contact distance), as well as being linear and symmetric with the iodine atom located in the center between the N atoms with a very small N–I distance variation. Over the last 5 years the field of halogen­(I) chemistry has expanded greatly, with recent developments including the first iodine­(I)-based capsules, − helicates, asymmetric complexes, , halogen-bonded organic frameworks (XOF), halogen-bonded hierarchical materials, and solid-state nucleophilic I + ···Ag + interactions. − …”