Organometallics 1983,2, 1577-1582 Tetra-l(E)-propenyldistibine (18). Compound 18 was prepared by method b from 4.0 g (16 mmol) of tri-l(E)propenylstibine and 0.74 g (32 mmol) of sodium in 100 mL of liquid ammonia. A 77% yield (2.5 g) of pure 18 was obtained as a yellow, air-sensitive liquid which freezes, mp -4 to -3 "C, to a yellow solid: lH NMR (C&) 6 1.80 (apparent d, 12 H), 6.15 (m, 8 H); IR (CC14)2990 (m), 2962 (m), 2942 (m), 2915 (s), 2870 (w), 2850 (m), 1609 (s), 1443 (s), 1375 (w), 1320 (w), 1200 (w) cm-';
