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[15]: m.p. = 133–135 ◦C). 1H NMR (400 MHz, CDCl3): 7.05 (4H,
d, J = 8.34, 2-H (Ar)), 7.25 (4H, d, J = 8.59, 3-H (Ar)). 31P NMR
(161 MHz, CDCl3): ı = −11.52.
Neodymium tris[bis(4-tert-butylphenyl) phosphate] (25) was
obtained from ester 12 (2.25 g, 6.2 mmol). Yield 2.41 g (98%). Anal.
C60H78NdO12P3 calcd. C 58.66, H 6.40; found C 58.73, H 6.39.
Neodymium tris[bis(4-chlorophenyl) phosphate] (26) was
obtained from ester 13 1.98 g (6.2 mmol). Yield 1.87 g (85%). Anal.
Bis(4-bromophenyl)-phosphoric acid (14) was obtained
from 4-bromophenol (18.2 g, 105 mmol). Yield 9.4 g (46%,
method B, hydrolysis in acetone), m.p. = 165–167 ◦C (lit. [16]:
m.p. = 165–167 ◦C). 1H NMR (400 MHz, CDCl3): 6.94 (4H, d, J = 8.84,
2-H (Ar)), 7.25 (4H, d, J = 8.84, 3-H (Ar)). 31P NMR (161 MHz, CDCl3):
ı = −11.85.
C36H24Cl6NdO12P3 calcd. C 39.36, H 2.20; found C 39.47, H 2.20.
Neodymium tris[bis(4-bromophenyl) phosphate] (27) was
obtained from ester 14 (2.53 g, 6.2 mmol). Yield 2.62 g (96%). Anal.
C36H24Br6NdO12P3 calcd. C 31.67, H 1.77; found C 31.78, H 1.76.
Neodymium tris[bis(4-fluorophenyl) phosphate] (28) was
Bis(4-fluorophenyl)-phosphoric acid (15) was obtained from
4-fluorophenol (11.8 g, 105 mmol). Yield 9.7 g (68%, method B,
hydrolysis in acetone), m.p. = 93–96 ◦C (lit. [17]: decomposes). 1H
NMR (400 MHz, CDCl3): 6.95 (4H, t, J = 8.80, 2-H (Ar)), 7.08 (4H, m,
J = 4.40, 3-H (Ar)). 31P NMR (161 MHz, CDCl3): ı = −10.62. 13C NMR
(MHz, CDCl3): ı = 116.38 (d, J = 23.42, 2,6-C), 121.54 (m, 4-C), 146,02
(d, J = 4.39, 3,5-C), 159.96 (d, J = 245.17, 1-C). Anal. C12H9F2O4P
calcd. C 50.36, H 3.17; found C 50.21, H 3.26.
obtained from ester 15 (1.77 g, 6.2 mmol). Yield 1.92 g (96%).
Anal. C36H24F6NdO12P3 calcd. C 43.25, H 2.42; found C 43.16, H
2.41.
2.3. Neodymium tris[bis(2,6-diisopropylphenyl) phosphate] (29)
Lithium metal (0.042 g, 6 mmol) was dissolved in methanol
(20 mL), and ester 2 (2.51 g, 6 mmol) was added. A solution of
neodymium chloride (0.72 g, 2 mmol) in methanol (10 mL) was
added to the resulting solution. The mixture was refluxed for 8 h,
and then the precipitated pink needle crystals (29ꢀ) were filtered
off and washed with methanol. 1H NMR (400 MHz, C6D6): ı = 0.12
(18H, br.s, 6CH3OH), 1.50 (72H, br.s, CH(CH3)2), 6.14 (12H, br.s,
CH(CH3)2), 7.14 (6H, m, p-H (Ar)) 7.32 (12H, d, J = 7.83, m-H (Ar)).
31P NMR (161 MHz, C6D6): ı = −0.80. 13C NMR (100 MHz, CDCl3):
ı = 23.97 (s, CH(CH3)2), 27.73 (s, CH(CH3)2), 38.84 (s, CH3OH),
124.31 (s, 3,5-C), 125.26 (s, 4-C), 142.58 (s, 2,6-C), 148.15 (s, 1-
C). 1H NMR (400 MHz, DMSO-d6 with CF3CO2H): ı = 1.14 (24H, d,
CH(CH3)2), ı = 3.20 (6H, s, CH3OH), 3.58 (4H, m, CH(CH3)2), 7.15
2.2. General procedure for the synthesis of neodymium tris-diaryl
phosphates 16–28
A solution of KOH (0.35 g, 6.2 mmol) in water (5 mL) was added
to a suspension of finely ground phosphoric acid ester (6.2 mmol)
in water (20 mL). Water (40 mL) and neodymium nitrate (0.88 g,
2 mmol) in water (30 mL) were added to the resulting solution with
stirring. After 4 h of stirring, the mixture was filtered and washed
with 4 mL × 40 mL of water. The white precipitate was dried in a
vacuum desiccator twice over CaCl2 and once over P2O5 to a con-
stant mass (the precipitate turned light blue).
Neodymium tris[bis(2,6-dimethylphenyl) phosphate] (16) was
obtained from ester 3 (9.65 g, 31.5 mmol) and neodymium nitrate
(4.38 g, 10 mmol). Yield 10.21 g (96%). Anal. C48H54NdO12P3 calcd.
C 54.38, H 5.13; found C 54.24, H 5.21.
Neodymium tris[bis(2,4,6-trimethylphenyl) phosphate] (17) was
obtained from ester 4 (2.07 g, 6.2 mmol). Yield 2.27 g (99%). Anal.
C54H66NdO12P3 calcd. C 56.68, H 5.81; found C 56.84, H 5.79.
Neodymium tris[bis(2,6-dimethyl-4-tert-butylphenyl) phosphate]
(18) was obtained from ester 5 (2.59 g, 6.2 mmol). Yield 2.49 g
(89%). 1H NMR (400 MHz, CDCl3): ı = 1.02 (54H, s, tert-Bu (Ar)),
2.31 (36H, s, Me (Ar)), 6.72 (12H, s, m-H (Ar)). 31P NMR (161 MHz,
CDCl3): ı = 57.95. 13C NMR (100 MHz, CDCl3): ı = 17.48 (s, 2,6-
Me (Ar)), 31.19 (s, C(CH3)3 (Ar)), 33.77 (s, C(CH3)3 (Ar)), 125.37
(s, 3,5-C), 130.65 (s, 2,6-C), 146.78 (s, 4-C), 147.63 (s, 1-C). Anal.
(6H, m, Н (Ar)). 31P NMR (161 MHz, CDCl3): ı = −11.76. FTIR (CCl4,
cm−1): 3644, 3586 (OH str. (MeOH)), 3068, 3029 ( CH str. (Ph)),
2969, 2932, 2870 ( CH str. (i-Pr)), 1470, 1442, 1386, 1362, 1334,
1257 ( HCH, CCH bend. (i-Pr)) 1095, 1072 (
P +
O, P O str. (PO4)−3
CO str. (MeOH)), 932 ( OPO bend. (PO4)−3). Yield 2.70 g (84%). Anal.
C
78H126NdO18P3 calcd. C 58.96, H 7.99; found C 59.10, H 7.95. The
product was dried in vacuo at 120 ◦C to a constant weight (the
precipitate acquired a blue colour). FTIR (CCl4, cm−1): 3068, 3029
(
CH str. (Ph)), 2969, 2932, 2870 ( CH str. (i-Pr)), 1470, 1442, 1386,
1362, 1334, 1257 ( HCH,CCH bend. (i-Pr)), 1095, 1072 ( O, P
str. (PO4)−3), 962 ( OPO bend. (PO4)−3). Yield 2.26 g (81%). Anal.
72H102NdO12P3 calcd. C 61.91, H 7.36; found C 61.73, H 7.45.
P
O
C
2.4. Preparation of the polymerisation catalyst
C72H102NdO12P3 calcd. C 61.91, H 7.36; found C 61.72, H 7.35.
Neodymium tris[bis(2,6-dimethyl-4-chlorophenyl) phosphate]
Isoprene, butadiene and piperylene were dried twice over gran-
ulated alumina and were recondensed into a tube with a metallic
tap containing granulated alumina.
(19) was obtained from ester 6 (2.33 g, 6.2 mmol). Yield 2.46 g
(97%). Anal. C48H48Cl6NdO12P3 calcd. C 45.51, H 3.82; found C
45.48, H 3.93.
Neodymium tris[bis(2,6-dimethyl-4-bromophenyl) phosphate]
(20) was obtained from ester 7 (2.88 g, 6.2 mmol). Yield 2.85 g
(93%). Anal. C48H48Br6NdO12P3 calcd. C 37.60, H 3.15; found C
37.49, H 3.37.
Neodymium tris[bis(2-methylphenyl) phosphate] (21) was
obtained from ester 8 (1.73 g, 6.2 mmol). Yield 1.78 g (91%). Anal.
C42H42NdO12P3 calcd. C 51.69, H 4.34; found C 51.58, H 4.53.
Neodymium tris[bis(2-methyl-4-tert-butylphenyl) phosphate]
(22) was obtained from of ester 9 (2.42 g, 6.2 mmol). Yield 2.44 g
(93%). Anal. C66H90NdO12P3 calcd. C 60.39, H 6.91; found C 60.18,
H 6.89.
2.4.1. Preparation with iBu3Al
A glass reactor was charged under argon with neodymium
derivative (0.1 mmol) and hexane (6.0 mL). 1,3-Diene (2 mmol) was
recondensed (−78 ◦C). The mixture was cooled to −78 ◦C, and a 1 M
solution of iBu3Al (3 mL) and/or iBu2AlH in hexane was added with
stirring. After 1 h, a 0.083 M solution of Et3Al2Cl3 (1 mL) in hexane
was added to the reaction mixture. The mixture was stirred for 24 h
at 20 ◦C and was then considered ready for use.
2.4.2. Preparation with iBu3Al + iBu2AlH
Neodymium tris(diphenyl phosphate) (23) was obtained from
ester 10 (1.55 g, 6.2 mmol). Yield 1.75 g (98%). Anal. C36H30NdO12P3
calcd. C 48.49, H 3.39; found C 48.56, H 3.47.
Neodymium tris[bis(4-methylphenyl) phosphate] (24) was
obtained from ester 11 (1.73 g, 6.2 mmol). Yield 1.87 g (96%). Anal.
C42H42NdO12P3 calcd. C 51.69, H 4.34; found C 51.80, H 4.42.
A glass reactor was charged under argon with neodymium
derivative (0.1 mmol) and hexane (6.75 mL). 1,3-Diene (2 mmol)
was recondensed (−78 ◦C). The mixture was cooled to −78 ◦C, and
a 1 M solution of iBu3Al (1.5 mL) in hexane and iBu2AlH (0.75 mL)
in hexane were added with stirring. After 1 h, a 0.083 M solution
of Et3Al2Cl3 (1 mL) in hexane was added to the reaction mixture.