High Productive Ethylene Trimerization Catalyst
1193
d) Bis-(2-cyclohexylsulfanyl-ethyl)-amine ligand (4)
2.5 General Procedure for the Preparation of SNS/
CrCl3 Catalysts
Ligand was colourless oil with 57% yield. IR (KBr)
(tmax cm-1): 3272 (NH), 2917 (CHaliphatic), 2849, 1445,
1343, 1263, 1200, 1122, 997, 886, 817, 735. 1H NMR
(400 MHz, CDCl3): dH 1.06–1.92 (20H, m, Cy), 2.90 (1H,
broad, NH), 2.46–2.55 (2H, m, Cy), 2.55 (4H, t,
SCH2CH2NH), 2.66 (4H, t, NHCH2). 13C NMR (125 MHz,
CDCl3): d 26.65, 30.11, 34.31, 44.25 (ring carbons), 33.44
(SCH2CH2NH), 49.17 (SCH2CH2NH). Elemental analysis:
calculated for C16H31NS2 (found): C 63.73 (63.24), H
10.36 (9.85), N 4.64 (4.95) and S 21.27 (22.56).
All SNS/CrCl3 catalysts were prepared according to the
following general procedure. A solution of 0.235 mmol of
the synthesized ligands in 5 mL THF was added to a
solution of 0.215 mmol CrCl3(THF)3 in 5 mL THF at room
temperature. The solution turned blue-green immediately
and was stirred for 10 min after which all the solvent was
removed in vacuum. Dried diethylether (10 mL) was added
to the residue and the solution was cooled overnight in a
refrigerator. The solution was then centrifuged and the
solid was washed with dried diethyl ether (3 9 10 mL),
then the solid was dried under vacuum.
e) Bis-(2-benzylsulfanyl-ethyl)-amine ligand (5)
Ligand was colourless semisolid with 37% yield. IR
(KBr) (tmax cm-1): 3282 (NH), 3057(CHaromatic), 2908–
2933 (CHaliphatic), 1600, 1492, 1452, 1237, 1237, 1198,
a) Bis-(2-dodecylsulfanyl-ethyl)-amine/CrCl3 catalyst (6)
The catalyst was blue-green solid with 80% yield. IR
(KBr) (tmax cm-1): 3183 (NH), 2920 (CHaliphatic), 1622
(Cr–Cl), 1464 (Cr–Cl), 1380, 1079, 995, 723 (Cr–Cl), 470
(Cr–N). Elemental analysis: calculated for C28H59Cl3
CrNS2 (found): C 53.19 (52.85), H 9.41 (9.96), N 2.22
(2.35) and S 10.14 (9.96).
1
1120, 1070, 765, 697, 661. H NMR (400 MHz, CDCl3):
dH 2.35 (1H, broad, NH), 2.57 (4H, t, SCH2CH2NH), 2.71
(4H, t, NHCH2), 3.59 (4H, s, SCH2ph), 7.23–7.5 (10 H, m,
ph). 13C NMR (125 MHz, CDCl3): d 31.02 (SCH2
CH2NH), 37.12 (SCH2ph), 48.64 (SCH2CH2NH),
127.95–139.29 (ph). Elemental analysis: calculated for
C18H23NS2 (found): C 68.09 (67.95), H 7.30 (7.85), N 4.41
(4.30) and S 20.20 (19.90).
b) Bis-(2-pentylsulfanyl-ethyl)-amine/CrCl3 catalyst (7)
The catalyst was blue-green solid with 85% yield. Ele-
mental analysis: calculated for C14H31Cl3CrNS2 (found): C
38.58 (37.45), H 7.17 (7.02), N 3.21 (3.45) and S 14.71
(14.30).
2.4 Ligand Oxidation
During preparation of the ligands under vacuum when the
temperature descends due to ether evaporation, a white
powder (SNS–OH) starts to appear. The (bulky with low
density) was filtered out and analyzed.
c) Bis-(2-ethylsulfanyl-ethyl)-amine/CrCl3 catalyst (8)
The catalyst was blue-green solid with 80% yield. Ele-
mental analysis: calculated for C8H19Cl3CrNS2 (found): C
27.32 (27.50), H 5.44 (5.91), N 3.98 (4.05) and S 18.23
(18.97).
a) N,N-Bis-(2-ethylsulfanyl-ethyl)-hydroxylamine
The byproduct of Bis-(2-ethylsulfanyl-ethyl)-amine
ligand was SNS-OH with 20% yield. IR (KBr) (tmax
cm-1): 3200–3400 (OH), 2990(CHaliphatic), 1460, 1380,
d) Bis-(2-cyclohexylsulfanyl-ethyl)-amine/CrCl3 catalyst
(9)
1
1269, 1141, 1053, 916, 762. H NMR (400 MHz, CDCl3):
The catalyst was blue-green solid with 70% yield. Ele-
mental analysis: calculated for C16H31Cl3CrNS2 (found): C
41.78 (41.34), H 6.79 (6.97), N 3.05 (3.26) and S 13.94
(13.58).
dH 1.27 (6 H, t, CH3), 2.62 (4H, q, SCH2CH3), 3.02 (4H, t,
SCH2CH2NOH), 3.17 (4H, t, NOHCH2), 9.71 (1H, s,
NOH). 13C NMR (125 MHz, CDCl3): d 15.51 (CH3), 26.89
(CH2CH3), 27.87 (SCH2CH2NOH), 47.84 (SCH2CH2
NOH).
e) Bis-(2-benzylsulfanyl-ethyl)-amine/CrCl3 catalyst (10)
The catalyst was blue-green solid with 65% yield. Ele-
mental analysis: calculated for C18H23Cl3CrNS2 (found): C
45.43 (45.05), H 4.87 (4.56), N 2.94 (2.67) and S 13.48
(13.84).
b) N,N-Bis-(2-cyclohexylsulfanyl-ethyl)-hydroxylamine
It was SNS-OH with 10% yield. IR (KBr) (tmax cm-1):
3200-3400 (OH), 2917 (CHaliphatic), 1445, 1343, 1263,
1200, 1122, 997, 886, 817, 735. 1H NMR (400 MHz,
CDCl3): dH 1.06–1.94 (20H, m, Cy), 2.69 (2H, m, Cy),
3.01 (4H, t, SCH2CH2NOH), 3.15 (4H, t, NOHCH2), 9.70
(1H, s, NOH). 13C NMR (125 MHz, CDCl3): d 26.70,
30.11, 34.35, 44.25 (ring carbons), 44.6 (SCH2CH2NOH),
48.2 (SCH2CH2NOH).
2.6 Trimerization
A 1 L stainless pressure reactor (Buchiglasuster bmd300,
Switzerland), equipped with a mechanical over-head stirrer,
control units for temperature, pressure, and stirrer speed was
123