207Pb NMR of minium, Pb3O4: evidence for the [Pb2]4+ ion and possible relativistic effects in the Pb-Pb bond.
Solid Pb3O4 has been studied with 207Pb nuclear magnetic resonance (NMR) spectroscopy. The 207Pb NMR chemical-shift tensor of the Pb2+ site has principal values of delta11 = 1980 +/- 5 ppm, delta22 = 1540 +/- 5 ppm, and delta33 = -1108 +/- 10 ppm; delta(iso) = 804 +/- 10 ppm. The chemical-shift tensor of the Pb4+ site is axial, with principal values delta(parallel) = -1009 +/- 3 ppm and delta(perpendicular) = 1132 +/- 3 ppm; delta(iso) = -1091 +/- 3 ppm. The Pb4+-Pb2+ scalar coupling constant J(Pb-Pb) = 2.3 +/- 0.1 kHz. The main contribution to the Pb2- chemical-shift anisotropy is proposed to arise from an exchange interaction in the Pb2+-Pb2+ pairs, conventionally regarded as molecular [Pb2]4+ ions.
Gabuda
S P
SP
Institute of Inorganic Chemistry, Novosibirsk, Russian Federation.
Kozlova
S G
SG
Terskikh
V V
VV
Dybowski
C
C
Neue
G
G
Perry
D L
DL
D002412:Cations / Q000737:chemistry; D007854:Lead / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy
D002412:Cations; D007854:Lead; C028356:lead tetroxide