Macromolecules
Article
2
22.1 Hz), 13.41 (d, J = 1.5 Hz), 3.71 (d, 3JCP = 12.7 Hz), 18.80 (s),
4
=
(
1
132.9 Hz, −P−C−), 7.28 (d, J = 7.1 Hz, −C). 31P{H} NMR
CP
CP
−1
31
CDCl , ppm): δ 52.51. FTIR (cm ): 2979, 2944, 2919, 2886 (P−C),
13.70 (s). P{H} NMR (CDCl , ppm): δ 51.56.
2-n-Butyl-2-oxo-1,3,2-dioxaphospholane ( BuPPn, 3). A flame-
3
3
n
476, 1265 (PO), 1241, 1027, 924, 806, 713.
i
Isopropylphosphonic Acid Dichloride (PrPCl). The dichloride was
dried three-necked round-bottom flask, equipped with a magnetic
stirring bar and two dropping funnels, was charged with 250 mL of dry
THF and cooled to −21 °C. n-Butylphosphonic acid dichloride (15.9
g, 0.09 mol) was dissolved in dry THF (250 mL) and transferred into
one dropping funnel via a flame-dried stainless steel capillary. A
solution of dry ethylene glycol (5.6 g, 0.09 mol) and dry pyridine (14.4
g, 0.18 mol) in THF (250 mL) was transferred into the second
dropping funnel via a flame-dried stainless steel capillary. Dropping
speed was adjusted to be approximately equal for both mixtures. After
complete addition the solution was stirred for 5 h and kept overnight
at −28 °C to facilitate the precipitation of the pyridinium
hydrochloride byproduct. The precipitate was removed by filtration
via a flame-dried Schlenk funnel, and the solvent was removed at
reduced pressure. Fractionated distillation yielded the desired product
28
synthesized according to the literature. A flame-dried 1 L three-
necked round-bottom flask was equipped with a dropping funnel and a
mechanical stirrer. Freshly ground aluminum trichloride (137.3 g, 1
mol) was provided, and phosphorus trichloride (135.1 g, 1 mol) was
added. The suspension was cooled to 5 °C and stirred vigorously.
Isopropyl bromide (122.9 g, 1.2 mol) was added dropwise so that the
temperature did not exceed 15 °C. During the addition the suspension
solidified and stirring had to be discontinued. The mixture was left to
stand at room temperature overnight. The solid was dissolved in
dichloromethane (500 mL); the solution was cooled to 0 °C by
addition of CO2(s) and poured onto a mixture of 1500 g of ice and 300
mL of concentrated hydrochloric acid. The phases were separated, and
the aqueous phase was extracted with dichloromethane. The combined
organic phases were dried with CaCl and evaporated to yield a black
liquid. Fractionated distillation yielded the desired product as a
colorless liquid (106.9 g, yield 66%, bp 86 °C/22 mbar). H NMR
CDCl , ppm): δ 2.76−2.61 (m, 1H), 1.42 (dd, J = 27.0 Hz, J
.0 Hz, 6H). C{H} NMR (CDCl , ppm): δ 41.83 (d, J = 94.6
Hz) 16.13 (d, J = 4.3 Hz). P{H} NMR (CDCl , ppm): δ 61.90.
−3
1
as colorless oil (5.6 g, yield 37%, bp 90 °C/1 × 10 mbar). H NMR
2
(
CDCl , ppm): δ 4.47−4.33 (m, 2H, −P−O−CH −), 4.27−4.14 (m,
3
2
1
2H, −P−O−CH −), 1.94−1.80 (m, 2H), 1.63−1.47 (m, 2H), 1.36 (h,
2
3 3 13
3
3
J
= 7.3 Hz, 2H), 0.85 (t, J = 7.3 Hz, 3H, −CH ). C{H} NMR
HH
HH
3
1
(
6
=
3
HP
HH
1
3
1
(CDCl , ppm): δ 66.16 (s, −P−O−C−), 25.40 (d, J = 117.0 Hz,
3
CP
3
CP
2
3
2
31
−P−C−), 24.5 (d, J = 8.2 Hz), 23.47 (d, J = 16.7 Hz), 13.44 (s,
CP
CP
CP
3
3
1
−
1
i
−C). P{H} NMR (CDCl , ppm): δ 51.64. FTIR (cm ): 2958,
2
-Isopropyl-2-oxo-1,3,2-dioxaphospholane (PrPPn, 2). A flame-
3
2
1
933, 2873 (P−C), 1467, 1407, 1380, 1365, 1259 (PO), 1219,
dried three-necked round-bottom flask, equipped with a magnetic
stirring bar and two dropping funnels, was charged with 250 mL of dry
THF and cooled to −21 °C. Isopropylphosphonic acid dichloride
025, 925, 846, 807, 749, 704.
Representative Procedure for the ROP of 1 and 3. The respective
monomer was placed in a flame-dried Schlenk tube, dissolved in dry
benzene, and dried by repeated lyophilization. The monomer was
dissolved in dry dichloromethane at a concentration of 4 mol L . A
(
47.8 g, 0.3 mol) was dissolved in dry THF (250 mL) and transferred
into one dropping funnel via a flame-dried stainless steel capillary. A
solution of dry ethylene glycol (18.5 g, 0.3 mol) and dry pyridine (47.9
g, 0.6 mol) in THF (250 mL) was transferred into the second
dropping funnel via a flame-dried stainless steel capillary. Dropping
speed was adjusted to be approximately equal for both mixtures. After
complete addition the solution was stirred for 5 h and kept overnight
at −28 °C to facilitate the precipitation of the pyridinium
hydrochloride byproduct. The precipitate was removed by filtration
via a flame-dried Schlenk funnel, and the solvent was removed at
reduced pressure. Fractionated distillation yielded the desired product
as colorless oil (18.3 g, yield 42%, bp 85 °C/1 × 10−3 mbar). H NMR
−1
stock solution of initiator 2-(benzyloxy)ethanol in dry dichloro-
−1
methane was prepared with a concentration 0.2 mol L , and the
calculated amount was added to the monomer solution via gastight
syringe (Hamilton). A stock solution of DBU in dry dichloromethane
was prepared with a concentration of 0.2 mol L . The monomer
solution and the catalyst solution were adjusted to 25 °C. The
polymerization was initiated by the addition of the calculated volume
of catalyst solution containing 3.0 equiv of DBU with respect to the
initiator. Polymerization was terminated after 16 h by the rapid
addition of an excess of formic acid dissolved in dichloromethane with
a concentration of 20 mg mL . The colorless, amorphous polymers
were purified by precipitation in cold diethyl ether for P(1) or hot
water for P(3) and dried under reduced pressure.
Representative NMR Data of P(1). H NMR (DMSO-d ppm): δ
−1
1
(
2
CDCl , ppm): δ 4.49−4.32 (m, 2H, −P−O−CH −), 4.29−4.12 (m,
−1
3
2
2
3
H, −P−O−CH −), 2.11 (dp, J = 18.1 Hz, J = 7.2 Hz, 1H,
2
HP
HH
3
3
−
P−CH−), 1.18 (dd, J = 19.3 Hz, J = 7.2 Hz, 6H, −CH ).
HP
HH
3
1
3
2
C{H} NMR (CDCl , ppm): δ 66.43 (d, J
= 0.9 Hz, −P−O−
1
3
COP
6
1
2
C−), 26.14 (d, J = 131.9 Hz, −P−C−), 16.22 (d, J = 4.6 Hz,
CP
CP
7.37−7.29 (m, aromatic protons), 4.85 (t, terminal −O−H), 4.53 (s,
−1
−
2
C). 31P{H} NMR (CDCl , ppm): δ 55.01. FTIR (cm ): 2970,
3
aryl−CH −), 4.22−4.01 (m, backbone −CH −CH −), 3.63 (t,
2
2
2
912, 2877 (P−C), 1466, 1388, 1367, 1244 (PO), 1026, 925, 890,
backbone terminal −CH −), 1.87−1.70 (m, side-chain −P−CH −),
2
2
13
865, 804, 689.
1
1
.14−0.98 (m, side-chain −CH ). C{H} NMR (DMSO-d , ppm): δ
3
6
n
O,O-Di-n-butyl-n-butylphosphonic Acid Diester ( BuPPn). Tri-n-
33.78, 128.80, 127.97 (aromatic carbons), 64.56 (s, broad, backbone
1
butylphosphite (138.6 g, 0.5 mol) and 1-iodobutane (51.7 g, 0.25 mol)
were refluxed in a 500 mL round-bottom flask equipped with a reflux
condenser at 160 °C for 1.5 h. Fractionated distillation yielded the
−
CP
CH −), 18.31 (d, J = 139.5 Hz, side-chain −P−CH −), 6.71 (d,
2
CP
2
2
31
J
= 6.75 Hz, side-chain −CH3). P{H} NMR (DMSO-d , ppm): δ
6
3
4.63 (backbone), 34.38 (terminal).
desired product as a colorless liquid (124.4 g, yield 99%, bp 133 °C/20
1
Representative NMR Data of P(3). H NMR (DMSO-d ,ppm): δ
6
1
mbar). H NMR (CDCl , ppm): δ 4.07−3.91 (m, 4H), 1.77−1.69 (m,
3
7.37−7.29 (m, aromatic protons), 4.85 (t, terminal −O−H), 4.53 (s,
3
2
9
(
1
H), 1.66−1.65 (m, 6H), 1.46−1.30 (m, 6H), 0.91 (t, J = 7.2 Hz,
HH
aryl−CH −), 4.22−4.01 (m, backbone −CH −CH −), 3.63 (t,
2
2
2
H). 13C{H} NMR (CDCl , ppm): δ 65.15 (d, J
2
= 5.3 Hz), 31.61
3
COP
backbone terminal −CH −), 1.86−1.70 (m, side-chain −P−CH −),
2
2
1
2
3
s), 25.23 (d, J = 105 Hz), 24.48 (d, J = 3.7 Hz), 3.71 (d, J
2.7 Hz), 18.80 (s), 13.70 (s). P{H} NMR (CDCl , ppm): δ 32.72.
n-Butylphosphonic Acid Dichloride ( BuPCl). A 100 mL two-
headed round-bottom flask was equipped with a reflux condenser, and
O,O-di-n-butyl-n-butylphosphonic acid diester (9.2 g, 0.04 mol) was
provided. The flask was heated to 150 °C, and phosphorus
pentachloride (15.4 g, 0.08 mol) was added carefully in small portions.
A vigorous gas and heat evolution indicated the progress of the
reaction. After complete addition the reaction was heated for another 1
h. Fractionated distillation yielded the desired product as a colorless
liquid (2.8 g, yield 40%, bp 103 °C/14 mbar). H NMR (CDCl ,
ppm): δ 2.68−2.49 (m, 2H), 1.90−1.72 (m, 2H), 1.51 (h, J = 7.3
Hz, 2H), 0.96 (t, J = 7.3 Hz, 3H). C{H} NMR (CDCl , ppm): δ
=
1.65−1.24 (m, side-chain −CH −CH −), 0.88 (t, side-chain −CH ).
CP
CP
CP
2
2
3
31
13
3
C{H} NMR (DMSO-d , ppm): δ 133.78, 128.80, 127.97 (aromatic
6
n
1
carbons), 64.56 (s, broad, backbone −CH −), 25.10 (d, J = 86.3
2
CP
2
Hz, side-chain −P−CH −), 24.40 (d,
J
= 52.5 Hz, side-chain
2
CP
3
−
CH −), 23.40 (d, J = 15.8 Hz, side-chain −CH −), 13.89 (s, side-
2
CP
2
31
chain CH ). P{H} NMR (DMSO-d , ppm): δ 33.39 (backbone),
3
6
33.15 (terminal).
Representative Procedure for the ROP of 2. 2 was placed in a
flame-dried Schlenk tube, dissolved in of dry benzene, and dried by
repeated lyophilization. The monomer was dissolved in dry dichloro-
methane at a concentration of 4 mol L . A stock solution of initiator
2-(benzyloxy)ethanol in dry dichloromethane was prepared with a
concentration of 0.2 mol L , and the calculated volume was added to
the monomer solution via gastight syringe (Hamilton). A stock
1
−1
3
3
HH
3
13
−1
HH
3
1
2
3
4
2.69 (d, J = 96.7 Hz), 24.87 (d, J = 6.6 Hz), 22.81 (d, J =
CP
CP
CP
I
Macromolecules XXXX, XXX, XXX−XXX