J. Am. Chem. SOC.1981,103, 5758-5767
5758
C H z = C H - C H = C H 2 ) ,4.600(m, 1, CH2==CH-CH=CH2), 1.380(d, 9,zJHp= 7.3 Hz, PMe,), 0.957(d, 9,zJHps 6.7Hz, PMe,'), 2.23,1.44, 1.15, 1.00,0.842,-0.161,-0.807, -0.919 (m, 1, olefinic resonances). The 4.826-and 4.600-ppm resonances coalesce at 75 f 10 OC [Av = 62 f 5 Hz, AG' = 17 i 1 kcal mol-']. I3C NMR (toluene-d,, 67.89 MHz, -30 "C): 94.87(d, ' J C H = 160 Hz, CHzjCH-CH=CH2), 92.57(d, 'JCH= 163 Hz, CH2=CH--CH=CH2), 51.79 (tt, ' J c p = 5.6 Hz, ' J C H = 147 Hz, CH2=CH2), 43.40 (ddd, 2Jcp= 5.7 Hz, ' J c H = 155 and 148 Hz, CHz=CHz), 34.75 (ddd, 2Jcp = 7.8 Hz,' J C H = 141 and 149 Hz, 30.19 (tt, 2Jcp 8.2 Hz, 'JCH ii: 150 Hz, CH2=CH-CH=CH2), CHz=CH-CH=CHz), 14.92 (qd, ' J c p 21.6 Hz, ' J c H = 130 Hz, PMe3), 13.54(qd, ' J c p = 23.3 Hz, ' J c H = 130 Hz, PMe,'). I3C NMR (15.0Hz, 60 "C): ethylene carbon atom resonances coalesce [T, = 60 f 10 OC, Av = 129 & 5 Hz, AG* = 16 f 1 kcal mol-']. 13CNMR (15.0 MHz, 100 "C): 93.95 (s, CHz=CH-CH=CH2), 47.8 (br s, CHz= CHI),33.1 (s, CHz=CH-CH=CHz), 14.9 ppm (d, lJcp ii: 12 Hz, PMe3). IIP NMR (CDCI,, 109.3 MHz, -30 "C): 6 2.0(s) and -8.3 (s) (major isomer), 2.5 (9) and -7.8 (s) (minor isomer). The ratio of the major to minor isomer was 2:l at -30 OC for this sample in this solvent. (14) Ta(1,Ibutadieae) (C2H4)(Et) (PMe3)2. Ta(C4H6)(C2H4) (CI)(PMe3)2(1.25 g, 2.77 mmol) was dissolved in ether (25 mL), and the sample of a 1.18 M LiCzHS solution was cooled to -78 OC. A 4.7" (excess) in benzene solution was added slowly by syringe. The reaction mixture was warmed to 25 OC, stirred for 30 min, and filtered. The solvent was removed in vacuo, and the residue was recrystallized from minimal pentane; yield 0.6 g (49%). Anal. Calcd for TaC14H33Pz:C, 37.84;H, 7.48. Found: C, 37.23; H, 7.32. 'H NMR (toluene-& 270 MHz, -40 "C): 6 4.92 (m, CH2=
3.46 (m, CHz=CH-CH=CH2), 1.30(d, 2JHp= 6 Hz,PMe3),0.87(d,2J~pii:6H~,PMe~),1.55,1.16,0.76,-0.16,and -0.37 (m, olefinic and CHz resonances), -0.05 (t. 'JHH= 7.7 Hz, CHzCH3). "C NMR (toluene-d,, 67.89 MHz, -40 OC): major isomer, 102.3 (d, 'JCH= 157 Hz, CHz=CH-CH=CHz), 89.0(d, ' J C H 163 Hz, CHZ=CH-CH=CH2), 48.6 ppm (tt, ' J C p = 5.7 Hz, ' J C H = 146 Hz, CH2=CHz), 42.1 (td, 2 J c p = 4.8 Hz, ' J C H = 149 Hz, C H y C H z ) , 33.9 (td, 2 J c p = 5.8 Hz, ' J c H = 150 Hz, CHZ-CH--CH=CH2), 33.6 (t, 'JCH= 116 Hz, CHZCH,), 25.1 (td, 2 J c p = 9.0 Hz, ' J c H 149 Hz, 15.0 (qd, ' J c p = 17.7 Hz,' J C H 130 Hz, CHz=CH-CH=CHz), PMe,), 13.5 (qd, ' J c p = 19.4 Hz, 'JCHEZ 130 Hz, PMe,'), 5.8 ppm (q, 'JCH 123 Hz, CHZCH,); minor isomer, 94.4(CHz=CH-CH=CHz), 92.3 (CHz=CH=CH
