3706
R. Gao et al. / Journal of Organometallic Chemistry 694 (2009) 3701–3707
4.2.4. (E)-2,6-diisopropyl-N-(1-(6-(benzoxazol-2-yl)pyridin-2-yl)-
ethylidene)benzenamine CrCl3 (Cr3)
filtered, washed with ethanol, and dried under vacuum at 60 °C to
constant weight.
Obtained as green powder in 96.6% yield. FT-IR (KBr; cmÀ1):
1618(mC@N) (m), 1560 (w), 1535 (m), 1446 (m), 1384 (vs), 1281
Acknowledgment
(m), 1180 (w), 1040 (w), 850 (w), 787 (s), 758 (s). Anal. Calc. for
C26H27Cl3CrN3O (555.87): C, 56.18; H, 4.90; N, 7.56. Found: C,
56.42; H, 5.11; N, 7.48%.
This work was supported by NSFC No. 20674089. We are grate-
ful to Mr. Amir Badshah (Department of Chemistry, Quaid-i-Azam
University, Pakistan) for the English improvement.
4.2.5. (E)-2,6-dichoro-N-(1-(6-(benzoxazol-2-yl)pyridin-2-yl)-
ethylidene)benzenamine CrCl3 (Cr4)
Appendix A. Supplementary material
Obtained as green powder in 90.8% yield. FT-IR (KBr; cmÀ1):
1619(mC@N) (m), 1564 (w), 1536 (m), 1434 (s), 1386 (s), 1284
CCDC 733233 contains the supplementary crystallographic data
for Cr3. These data can be obtained free of charge from The Cam-
(m), 1088 (w), 1036 (w), 861 (w), 788 (s). Anal. Calc. for
C20H13Cl4CrN3O (540.6): C, 44.43; H, 2.42; N, 7.77. Found: C,
44.57; H, 2.64; N, 7.62%.
4.2.6. (E)-2,4,6-trimethyl-N-(1-(6-(benzoxazol-2-yl)pyridin-2-yl)-
ethylidene)benzenamine CrCl3 (Cr5)
Obtained as green powder in 91.2% yield. FT-IR (KBr; cmÀ1):
References
1619(mC@N) (m), 1566 (w), 1536 (m), 1444 (m), 1386 (vs), 1282
(m), 1219 (m), 1036 (m), 856 (w), 759 (s). Anal. Calc. for
C23H21Cl3CrN3O (513.79): C, 53.77; H, 4.12; N, 8.18. Found: C,
53.46; H, 4.41; N, 8.22%.
[1] T.J. Pullukat, R.E. Hoff, Catal. Rev. Sci. Eng. 41 (1999) 389.
[2] B. Liu, H. Nakatani, M. Terano, J. Mol. Catal. A: Chem. 201 (2003) 189–197.
[3] P.S.B. Liu, M. Terano, J. Mol. Catal. A: Chem. 238 (2005) 142–150.
[4] B. Liu, H. Nakatani, M. Terano, J. Mol. Catal. A: Chem. 184 (2002) 387–398.
[5] P. Pino, R. Mülhaupt, Angew. Chem., Int. Ed. Engl. 19 (1980) 857–875.
[6] G.G. Hlatky, Chem. Rev. 100 (2000) 1347–1376.
[7] G. Fink, B. Steinmetz, J. Zechlin, B. Tesche, Chem. Rev. 100 (2000) 1377–1390.
[8] B.L. Small, M. Brookhart, A.M.A. Bennett, J. Am. Chem. Soc. 120 (1998) 4049–
4050.
4.2.7. (E)-4-bromo-2,6-dimethyl-N-(1-(6-(benzoxazol-2-yl)pyridin-2-
yl)ethylidene)benzenamine CrCl3 (Cr6)
Obtained as green powder in 88.0% yield. FT-IR (KBr; cmÀ1):
[9] G.J.P. Britovsek, V.C. Gibson, B.S. Kimberley, P.J. Maddox, S.J. McTavish, G.A.
Solan, A.J.P. White, D.J. Williams, Chem. Commun. (1998) 849–850.
[10] G.J.P. Britovsek, S. Mastroianni, G.A. Solan, S.P.D. Baugh, C. Redshaw, V.C.
Gibson, A.J.P. White, D.J. Williams, M.R.J. Elsegood, Chem. Eur. J. 6 (2000)
2221–2231.
[11] R.D. Kohn, G. Kociak-Kohn, Angew. Chem., Int. Ed. Engl. 33 (1994) 1877–1878.
[12] R.D. Köhn, M. Haufe, G. Kociak-Köhn, S. Grimm, P. Wasserscheid, W. Keim,
Angew. Chem., Int. Ed. Engl. 39 (2000) 4337–4339.
1619(mC@N) (m), 1563 (w), 1535 (m), 1445 (s), 1386 (s), 1282
(m), 1180 (w), 1036 (w), 851 (w), 788 (s). Anal. Calc. for
C22H18BrCl3CrN3O (578.66): C, 45.66; H, 3.14; N, 7.26. Found: C,
45.78; H, 3.22; N, 7.37%.
4.3. Crystal structure determination
[13] R.D. Köhn, M. Haufe, S. Mihan, D. Lilge, Chem. Commun. (2000) 1927–1928.
[14] W.K. Reagen, Chem. Soc. Symp., Div. Petrol. Chem. 34 (1989) 583–588.
[15] W.K. Reagen (to Phillips Petroleum Company), EP 0417477, 1991.
[16] W.K. Reagen, B.K. Conroy (to Phillips Petroleum Company), US 5, 288, 823,
1994.
[17] W.K. Reagen, T.M. Pettijohn, J.W. Freeman (to Phillips Petroleum Company), US
Patent 5523507, 1996.
[18] D.F. Wass, Dalton Trans. (2007) 816–819.
Single-crystal of Cr3 suitable for X-ray diffraction studies were
obtained by slow evaporation of diethyl ether to its methanol solu-
tion. Single-crystal X-ray diffraction studies for Cr3 were carried
out on a Rigaku RAXIS Rapid IP diffractometer with graphite mono-
chromated Mo Ka radiation (k = 0.71073 Å). Cell parameters were
obtained by global refinement of the positions of all collected
reflections. Intensities were corrected for Lorentz and polarization
effects and empirical absorption. The structures were solved by di-
rect methods and refined by full-matrix least squares on F2. All
non-hydrogen atoms were refined anisotropically. All hydrogen
atoms were placed in calculated positions. Structure solution and
refinement were performed by using the SHELXL-97 package [69].
Crystal data and processing parameters for Cr3 are summarized
in Table 6.
[19] J.T. Dixon, M.J. Green, F.M. Hess, D.H. Morgan, J. Organomet. Chem. 689 (2004)
3641–3668.
[20] V.C. Gibson, P.J. Maddox, C. Newton, C. Redshaw, G.A. Solan, A.J.P. White, D.J.
Williams, Chem. Commun. (1998) 1651–1652.
[21] V.C. Gibson, C. Newton, C. Redshaw, G.A. Solan, A.J.P. White, D.J. Williams, J.
Chem. Soc., Dalton Trans. (2002) 4017–4023.
[22] V.C. Gibson, C. Newton, C. Redshaw, G.A. Solan, A.J.P. White, D.J. Williams, Eur.
J. Inorg. Chem. (2001) 1895–1903.
[23] W.K. Kim, M.J. Fevola, L.M. Liable-Sands, A.L. Rheingold, K.H. Theopold,
Organometallics 17 (1998) 4541–4543.
[24] L.A. McAdams, W.-K. Kim, L.M. Liable-Sands, I.A. Guzei, A.L. Rheingold, K.H.
Theopold, Organometallics 21 (2002) 952–960.
[25] L.A. MacAdams, G.P. Buffone, C.D. Incarvito, A.L. Rheingold, K.H. Theopold, J.
Am. Chem. Soc. 127 (2005) 1082–1083.
[26] P. Wei, D.W. Stephan, Organometallics 21 (2002) 1308–1310.
[27] T. Ruther, K.J. Cavell, N.C. Braussaud, B.W. Skelton, A.H. White, J. Chem. Soc.,
Dalton Trans. (2002) 4684–4693.
[28] T. Ruther, N. Braussaud, K.J. Cavell, Organometallics 20 (2001) 1247–1250.
[29] V.C. Gibson, S. Mastroianni, C. Newton, J. Chem. Soc., Dalton Trans. (2000)
1969–1971.
[30] D.J. Jones, V.C. Gibson, S.M. Green, P.J. Maddox, Chem. Commun. (2002) 1038–
1039.
[31] V.C. Gibson, C. Newton, C. Redshaw, J. Chem. Soc., Dalton Trans. (1999) 827–
830.
[32] D.S. McGuinness, P. Wasserscheid, W. Keim, C. Hu, U. Englert, J.T. Dixon, C.
Grove, Chem. Commun. (2003) 334–335.
[33] A. Carter, S.A. Cohen, N.A. Cooley, A. Murphy, J. Scutt, D.F. Wass, Chem.
Commun. (2002) 858–859.
[34] M.E. Bluhm, O. Walter, M. Döring, J. Organomet. Chem. 690 (2005) 713–721.
[35] D.S. McGuinness, P. Wasserscheid, D.H. Morgan, J.T. Dixon, Organometallics 24
(2005) 552–556.
4.4. General procedure for ethylene activation
Ethylene oligomerization at 10 atm ethylene pressure was car-
ried out in a 500 ml autoclave stainless steel reactor equipped with
a mechanical stirrer and a temperature controller. Briefly, toluene,
the desired amount of cocatalyst, and a toluene solution of the cat-
alytic precursor (the total volume was 100 mL) were added to the
reactor in this order under an ethylene atmosphere. When the de-
sired reaction temperature was reached, ethylene at 10 atm pres-
sure was introduced to start the reaction, and the ethylene
pressure was maintained by constant feeding of ethylene. After
30 min, the reaction was stopped. A small amount of the reaction
solution was collected, the reaction was terminated by the addition
of 5% aqueous hydrogen chloride, and then this mixture was ana-
lyzed by gas chromatography (GC) to determine the distribution
of oligomers obtained. The remaining solution was quenched with
HCl–acidified ethanol (5%), and the precipitated polyethylene was
[36] K. Blann, A. Bollmann, J.T. Dixon, F.M. Hess, E. Killian, H. Maumela, D.H.
Morgan, A. Neveling, S. Otto, M.J. Overett, Chem. Commun. (2005) 620–621.
[37] M.J. Overett, K. Blann, A. Bollmann, J.T. Dixon, F. Hess, E. Killian, H. Maumela,
D.H. Morgan, A. Neveling, S. Otto, Chem. Commun. (2005) 622–624.