화학공학소재연구정보센터
Inorganic Chemistry, Vol.48, No.9, 4021-4030, 2009
Long-Range Through-Bond Heteronuclear Communication in Platinum Complexes
Four analogous platinum stilbene- and stilbazole-based complexes exhibit unusual long-range heteronuclear spin-spin coupling in solution. Single crystal analysis and NMR experiments show that the F-19, P-31, and Pt-195 nuclei communicate over large distances (0.9-1.3 nm) through bond rather than through space. Spin-spin couplings between Pt-195 and F-19 over seven bonds and between P-31 and F-19 over eight bonds are observed with (7)J(PtF) = 2.9 Hz and (8)J(PF) = 11.8 Hz. Remarkably, a very large spin coupling between Pt-195 and F-19 over six bonds ((6)J(PtF) = 40.1 Hz) is also observed in a structurally related pyridinium complex. Experimental and gNMR (version 5.0) simulated F-19(H-1), P-31{H-1}, and Pt-195{H-1} spectra of the complexes reveal a three-spin AMY system (A = P-31, M = P-31, Y = F-19) or a five-spin AMY(3) flanked by a four-spin AMXY or a six-spin AMXY(3) system (X = Pt-195), respectively. Density functional theory calculations at the PBE0/SDD level of theory show a pi-conjugated metal-ligand network, which may contribute to the experimentally observed spin-spin interactions.