摘要
While the synthetic utility and reactivity of the so-called 鈥淕aI鈥?species is reasonably well established, its exact composition remains unknown. Using primarily multinuclear magnetic resonance techniques (and supported with powder X-ray diffraction measurements), we offer some new insights into the composition of 鈥淕aI鈥? Using p>127p>I nuclear quadrupole resonance (NQR) experiments, it is clearly demonstrated that gallium diiodide (GaI2) is a significant component of this material, while GaI3 is not. This finding is in contrast with a prior literature account, which noted that Ga2I3 (i.e., one equivalent of GaI3 per equivalent of Ga metal) was present in significant amounts. Additional solid-state nuclear magnetic resonance (SSNMR) experiments using the p>69/71p>Ga probe nuclei in multiple magnetic fields clearly establish, via its diagnostic Knight-shifted resonance, the presence of Gap>0p> metal, which is in agreement with prior literature. Taken together, a composition may be tentatively offered: that 鈥淕aI鈥?is, to a large extent, two equivalents of Gap>0p> metal with two equivalents of GaI2, where the latter is composed of Gap>+p> and ions. This composition may be represented as [Gap>0p>]2[Ga]p>+p>[GaI4]p>鈭?/sup>.