Nuclear quadrupole resonance of ²D and ¹⁷O in ices V, VI, VIII, and IX

Using double nuclear resonance with spin mixing by level crossing (DRLC) and by continuous coupling (DRCC) the nuclear quadrupole resonance of ¹⁷O and ²D has been measured as a function of isotopic enrichment in the high-pressure ice forms Ice V, Ice VI, Ice VIII, and Ice IX. The deuteron quadrupole coupling constant is a sensitive probe of slight structure changes. In Ice VIII there is only one site, in Ice IX three unique sites are detected, and in Ice V and Ice VI an unresolved complicated spectrum is obtained. Quadrupole coupling constants that span all the deuterons in the various ice forms are V e²qQ h = 223 + 4 kHz, η = 0.11 ± 0.02, VI e²qQ h = 227 ± 10 kHz, η < 0.20, VIII e²qQ h = 236.2 ± 0.3 kHz, η = 0.102 ± 0.005, IX e²qQ h = 220 ± 3 kHz, η = 0.12 ± 0.03, There is a good linear correlation between ( e²qQ h) and the square of the OD stretching frequency ν_OD (HDO) and with the O-D bond length. The ¹⁷O quadrupole coupling constants are much less sensitive to structure changes. The values obtained were V e²qQ h = 6983 ± 10 kHz, η = 0.865 ± 0.007, VI e²qQ h = 6970 ± 80 kHz, η = 0.90 ± 0.02, VIII e²qQ h = 7140 ± 100 kHz, η = 0.97 ± 0.03, IX e²1Q h = 6766 ± 10 kHz, η= 0.896 ± 0.007.