A new Cl-Cl···O-N halogen-bonded paradigm has been demonstrated, using dichlorine as a halogen bond (XB) donor and -oxide as an XB acceptor. Their crystalline complexes were formed during the warm-up process from -196 °C to -80 °C for X-ray diffraction analysis. They exhibit high instability in the crystalline state, even at these low temperatures, leading to rapid decomposition and the formation of Cl⋯H-O-N hydrogen-bonded complexes.
View Article and Find Full Text PDFThe N─Oxide oxygen in the 111 C─I···⁻O─N halogen bond (XB) complexes, formed by five perfluoroiodobenzene XB donors and 32 pyridine N-oxides (PyNO) XB acceptors, exhibits three XB modes: bidentate, tridentate, and monodentate. Their C─I···O XB angles range from 148° to 180°, reflecting the iodine σ-hole's structure-guiding influence. The I···⁻O─N angles range from 87° to 152°.
View Article and Find Full Text PDFThe nature of (imide)N-X⋯N(pyridine) halogen-bonded complexes formed by six N-haloimides and sixteen 2-substituted pyridines are studied using X-ray crystallography (68 crystal structures), Density Functional Theory (DFT) (86 complexation energies), and NMR spectroscopy (90 association constants). Strong halogen bond (XB) donors such as N-iodosuccinimide form only 1:1 haloimide:pyridine crystalline complexes, but even stronger N-iodosaccharin forms 1:1 haloimide:pyridine and three other distinct complexes. In 1:1 haloimide:pyridine crystalline complexes, the haloimide's N─X bond exhibits an unusual bond bending feature that is larger for stronger N-haloimides.
View Article and Find Full Text PDFThe coordination nature of 2-mono- and 2,6-disubstituted pyridines with electron-withdrawing halogen and electron-donating methyl groups for [N-X-N] (X=I, Br) complexations have been studied using N NMR, X-ray crystallography, and Density Functional Theory (DFT) calculations. The N NMR chemical shifts reveal iodine(I) and bromine(I) prefer to form complexes with 2-substituted pyridines and only 2,6-dimethylpyridine. The crystalline halogen(I) complexes of 2-substituted pyridines were characterized by using X-ray diffraction analysis, but 2,6-dihalopyridines were unable to form stable crystalline halogen(I) complexes due to the lower nucleophilicity of the pyridinic nitrogen.
View Article and Find Full Text PDF[PtCl{Te(CH)}] () was synthesized from the cyclic telluroether Te(CH) and -[PtCl(NCPh)] in dichloromethane at room temperature under the exclusion of light. The crystal structure determination showed that in the solid state, crystallizes as yellow plate-like crystals of the -isomer and the orange-red interwoven needles of . The crystals could be separated under the microscope.
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