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M.A. Torzilli et al. / Polyhedron 21 (2002) 697ꢁ704
/
8.23 (1H, s, NCH), 7.20 (1H, t, H5), 7.14 (1H, d, H6),
6.87 (1H, d, H3), 6.77 (1H, t, H4), 3.46 (2H, t, NCH2),
1.63 (2H, m, NCH2CH2), 0.89 (3H, t, CH3) ppm.
light yellow powder (55%). This compound could be
recrystallized from acetone and water to obtain a
colorless microcrystalline product. Anal. Found: C,
61.59; H, 6.08; N, 7.05. Calc. for C20H24N2O2Zn: C,
61.62; H, 6.21; N, 7.19%. Electronic spectrum (CHCl3, o
Mꢀ1 cmꢀ1): 316 (6200), 369 (3100) nm FTIR (KBr):
3083(w), 3048(w), 3025(w), 2974(w), 2956(w), 2933(m),
2908(m, br), 2864(m), 1626(vs), 1600(m), 1535(s),
1470(s), 1447(s), 1407(m), 1348(m), 1329(m), 1240(w),
1189(m), 1148(m), 1125(w), 1052(m), 1031(w), 1017(w),
982(w), 922(w), 887(m), 850(w), 795(w), 752(m), 741(m),
654(w), 600(w), 562(w), 512(w), 464(m) cmꢀ1. 1H NMR
(CDCl3) d 8.17 (1H, s, NCH), 7.29 (1H, t, H5), 7.11
(1H, d, H6), 6.85 (1H, d, H3), 6.60 (1H, t, H4), 3.51 (2H,
t, NCH2), 1.64 (2H, m, NCH2CH2), 0.88 (3H, t, CH3)
ppm.
2.3.2. (LprH)(CF3SO3)
In a 100 ml Schlenk tube, 0.429 g (2.63 mmol) of N-n-
propylsalicylaldimine was added to 20 ml of anhydrous
diethyl ether under argon. To this solution, 0.760 ml
(0.448 g, 2.99 mmol) of trifluoromethanesulfonic acid
was added in drops with vigorous stirring. The resulting
cloudy, slightly pink suspension was stirred for 5 min,
then filtered and washed with anhydrous diethyl ether to
yield 0.780 g of a white solid after drying under vacuum
(95% yield). The compound could be recrystallized from
hot chloroform. Anal. Found: C, 42.16; H, 4.46; N,
4.45; F, 18.31. Calc. for C11H14F3NOS: C, 42.17; H,
4.50; N, 4.47; F, 18.19%. IR (KBr): 3214(s), 3140(m, br),
3006(m), 2973(m), 2885(w), 1674(m), 1611(m), 1502(w),
1459(w), 1381(w), 1360(w), 1280(vs), 1245(vs), 1223(s),
1151(m), 1061(w), 1031(s), 1000(w), 903(w), 882(w),
2.3.5. Zn(Lpr)2 prepared from Zn(LprH)2Cl2
758(m), 645(m), 574(w), 517(w), 447(w) cmꢀ1
.
In a 125 ml Erlenmeyer flask, 0.179 g (0.387 mmol) of
Zn(LprH)2Cl2 was added followed by 16.8 ml (0.769
mmol) of aqueous 0.0458 M NaOH with stirring. The
solution initially became a light yellow suspension
followed by the formation of a white precipitate. After
2 h the product was filtered and dried under vacuum to
yield 0.136 g of an off-white solid (90%). Alternatively,
solid Zn(LprH)2Cl2 (0.110 g, 0.238 mmol) was dissolved
in 15 ml of chloroform with stirring in a 25 ml round
bottom flask. The slightly cloudy yellow solution
became clear and pale yellow after 0.0485 g (0.479
mmol) of Et3N was added by syringe. The chloroform
solution was evaporated on a rotoevaporator and the
resulting solid was triturated with deionized water until
chloride free (by testing with AgNO3(aq)). The solid was
then dried under vacuum to yield 0.083 g of off-white
product (89%). This material was judged to be pure
based on 1H NMR and IR spectroscopic measurements.
2.3.3. Zn(LprH)2Cl2
In a 100 ml Schlenk tube, 1.10 g (6.74 mmol) of N-n-
propylsalicylaldimine was dissolved in 12 ml of dry
benzene (distilled over LiAlH4) under Ar. A 3.3 ml
solution of 1.0 M ZnCl2 (3.3 mmol) in diethyl ether
(Aldrich) was then added via syringe in drops forming a
thick orange oil. With vigorous manual agitation the oil
slowly changed to a yellow solid after approximately 0.5
h. The reaction mixture was allowed to stir for an
additional 1.5 h. The solid was filtered and washed in air
with 5 ml of benzene and diethyl ether (3ꢄ5 ml) to yield
/
1.493 g of a yellow powder after drying under vacuum
(98% yield). Anal. Found: C, 51.57; H, 5.58; N, 6.00; Cl,
14.93. Calc. for C20H26Cl2N2O2Zn: C, 51.91; H, 5.66; N,
6.05; Cl, 15.32%. m.p. 151ꢁ154 8C. Electronic spectrum
/
(CHCl3, o Mꢀ1 cmꢀ1): 316 (7300), 390 (2300) nm.
FTIR (KBr): 3060(m, br), 2977(sh), 2957(m), 2935(m),
2877(w), 1658 (vs), 1607(s), 1542(s), 1490(s), 1459(w),
1344(w), 1302(m), 1288(m), 1232(m), 1202(m), 1141(m),
1027(m), 989(w), 911(w), 894(w), 8649w), 787(w), 759(s),
7349(w), 583(m), 514(w), 490(w), 450(w) 434(w),
2.3.6. Zn(LprH)2Cl2 prepared from Zn(Lpr)2
A 2.1 ml (2.1 mmol) aliquot of a 1.0 M solution of
HCl in diethyl ether (Aldrich) was added via syringe in
drops to a rapidly stirring solution of 0.391 g (1 mmol)
of Zn(Lpr)2 in 20 ml of benzene in a Schlenk tube under
argon. The reaction mixture immediately became cloudy
and yellow. After several minutes of stirring, a thick
orange oil formed. Continued stirring yielded a yellow
solid after 1 h. The solvent was decanted and the
remaining solid was washed with 5 ml of benzene
4169(w) cmꢀ1 1H NMR (CDCl3) d 13.6 (1H, s br,
.
OH), 8.16 (1H, s, NCH), 7.37 (1H, t, H5), 7.23 (1H, d,
H6), 7.11 (1H, d, H3), 6.74 (1H, t, H4), 3.61 (2H, t,
NCH2), 1.79 (2H, m, NCH2CH2), 0.99 (3H, t, CH3)
ppm.
2.3.4. Zn(Lpr)2
To a solution of 1.50 g (9.19 mmol) of N-n-
propylsalicylaldimine in 20 ml of ethanol, 1.01 g (4.60
mmol) of Zn(O2CCH3)2×
A pale yellow precipitate formed after several minutes
and was stirred for an additional 45 min. The precipitate
was filtered and dried under vacuum to yield 0.98 g of a
followed by 3ꢄ10 ml of diethyl ether and dried to
/
/
2H2O was added with stirring.
yield 0.428 g of product (92%). Both preparations
1
yielded material that was pure based on H NMR and
IR spectroscopic measurements.
Torzilli, Michele A.
