Halogen bonds with coordinative nature: halogen bonding in a S–I⁺–S iodonium complex

Abstract

A thorough characterization of unusually strong I+–S halogen bonds indicates that halogen bonding is not merely an electrostatic contact but also has a strong coordinative nature, thus expanding the scope of halogen bonding.

Solvent Effects on Nitrogen Chemical Shifts

“…12) of up to 10-25 ppm, which is slightly lower than that observed for the "pyridine-type" nitrogens of diazoles 58-59 and triazoles 60-63 [56]. (70), and thiadiazoles, e.g., 1,2,5-thiadiazole (71), 1,3,4-thiadiazol (72), 1,2,4-thiadiazole (73), and 1,2,3-thiadiazole (74, Fig. 13) undergo larger solvent induced δ 14N variation, 11-30 ppm, than the corresponding diazoles 58-59 and triazoles 60-63 (Table 3) [57].…”

“…Here, it should be noted that δ 15N lig itself is also negative, when external nitromethane is used as reference. Coordination shifts of comparable magnitude have been reported for halogen(I) complexes [67][68][69], which show notable geometrical similarities to analogous bidentate Ag(I) and Au(I) complexes [70,71]. For smooth comparison of various species, Δ 15N coord is often reported as its absolute value, jΔ 15N coord j.…”

“…We discuss examples including the complexes of nitrogenous ligands with metals that belong to groups 8-12 of the periodic table, and with halogen(I) that were demonstrated to possess high similarities ( Fig. 14) [70,71]. …”

Halogen Bonding in Solution

“…Accordingly, the mass (HRMS) of the chlorine-centered complex corresponded to that of the hydrochloric acid adduct of the ligand. Koskinen et al has recently described analogous [S-I-S] + complexes in the solid state [126]. Three-center halogen bonds were reviewed [127].…”

Role of Weak Hydrogen Bonds and Halogen Bonds in 5-Halo-1,3-dimethyluracils and Their Cocrystals—A Combined Experimental and Computational Study

“…6 Despite the work already performed, there remains a need to investigate small biomolecular systems where XBs and non-conventional HBs, such as C-H … O, are simultaneously present, as the latter interactions are ubiquitous in many small molecule crystal structures 24,25 and advantageously used for enhancing the efficiency of weak base pairing in DNA. [26][27][28][29][30][31][32][33] Due to our continuing interest in the potential of pyrimidine nucleobases for crystal engineering strategies underpinned by multiple HBs [34][35][36][37][38][39][40][41][42][43][44][45] and our involvement in studies of systems exhibiting halogen bonding via alternative donors (halogen atom not polarized by fluorine) and acceptors (such as anions), [46][47][48][49][50][51][52][53][54][55][56][57][58][59] we were interested in search for systems that could be used to investigate the role of concurrent XBs and non-conventional HBs in the control of sequence, structure and flexibility of DNA halogenated within the natural tract. For this purpose, 5-halogenated derivatives (DMXU; X=F, Cl, Br, I) of N,N-1,3-dimethyluracil (DMHU) and their mixed cocrystals are ideal candidates because of several advantageous properties.…”