... Inorganic Chemistry Communications. ... tubes): Bruker ARX 250: 1 H (250.1 MHz), 13 C (62.9 MHz), and 29 Si NMR (49.7 MHz; refocused INEPT based on 2 J( 29 Si, 1 H)=7 Hz); chemical shifts are ... E Buncel, JR Jones (Eds.), Isotopes in the Physical and Biomedical Sciences, vol. ...