Rapid Identification of Halogen Bonds in Co-Crystalline Powders via 127 I Nuclear Quadrupole Resonance Spectroscopy

摘要: 127 I nuclear quadrupole resonance (NQR) spectroscopy is established as a rapid and robust method to indicate the formation of iodine-nitrogen halogen bonds in co-crystalline powders. Once relevant spectral frequency range has been established, diagnostic NQR spectra can be acquired seconds. The demonstrated for series co-crystals 1,4-diiodobenzene. Changes quadrupolar coupling constant (CQ ) by up 74.4 MHz correlate with length C-I donor covalent bond inversely I⋅⋅⋅N halogen-bond length. predictive power this technique validated on two previously unknown powders prepared mechanochemically. Single-crystal growth via co-sublimation structure determination single-crystal X-ray diffraction cross-validates findings. Natural localized molecular-orbital analyses provide insight into origins constants.