Unexpected chemical bonding in quantum confined layers in TlZrF5

NMR203 and 205Tl spectra of TlZrF5 have been measured. The large 205Tl chemical shift anisotropy (Δσxx = 510 ± 10 ppm; Δσyy = 90 ± 10 ppm; Δσzz = −660 ± 10 ppm; 〈σ〉R = −70 ± 10 ppm) and indirect exchange exchange interaction of 203,205Tl nuclear spins in Tl layers (J = 14.4 kHz; B = 3.5 kHz) reveal the involvement of 6s6pσ hybrid orbitals in the TlTl bonding. The energy gap between the bonding hybrid 6s6pσ, and nonbonding 6s2 orbitals in ΔE = (3.65 ± 0.6) × 10−3 eV.