Coordination Studies of a New K4-PNN′N′′-Tetradentate Ligand
Preparation of 2-{Ph2PC6H4C(H)dN}C6H4{N(H)COCH2N-
(H)CO2Bz} (2‚HH). A suspension of 1 (1.001 g, 3.344 mmol),
2-Ph2PC6H4(CHO) (1.001 g, 3.448 mmol), and a catalytic quantity
of 4-CH3C6H4SO3H (0.055 g, 0.289 mmol) in absolute EtOH (50
mL) was refluxed, under a nitrogen atmosphere, for 2 h. After the
yellow solution was cooled to room temperature, a yellow solid
deposited and was collected by suction filtration. The solid 2‚HH
was washed with a small portion of EtOH and dried in vacuo.
Yield: 1.164 g (61%). Selected data: 31P (CDCl3): -10.0 ppm.
(CO), 1681 (Amide I), 1508 (Amide II), 273 (PdCl) cm-1. ES-
MS: m/z 676 [M - 2Cl]. Anal. Calcd for C35H30Cl2N3O3PPd‚
0.25OEt2: C, 52.53; H, 3.99; N, 5.11. Found: C, 52.78; H, 4.20;
N, 4.70. Compound 4c was similarly prepared from 2‚HH and Pd-
(CH3)Cl(cod) in 92% yield. Selected data for 4c: 31P (CDCl3): 36.9
ppm. 1H (CDCl3): 8.90 (s, 1H, CHdN), 8.07 (s, 1H, NH), 7.58-
3
7.01 (m, 22H, arom. H), 6.14 (d, J(HH) 7.5, 1H, arom. H), 5.44
(s, 1H, NH), 4.89 (s, 2H, OCH2), 3.85 (d, 3J(HH) 5.6, 2H, NCH2),
3
0.60 (d, J(HP) 3.1, 3H, PdCH3) ppm. FT-IR (KBr): 3346, 3330
1H (CDCl3): 9.57 (s, 1H, NH), 8.97 (d, J(HP) 3.6, 1H, CHdN),
(NH), 1722 (CO), 1682 (Amide I), 1508 (Amide II) cm-1. ES-
MS: m/z 714 [M - CΗ3]. Anal. Calcd for C36H33ClN3O3PPd: C,
59.35; H, 4.57; N, 5.77. Found: C, 59.13; H, 4.46; N, 5.58.
Preparation of MCH3(2‚H) (M ) Pt, 5a; M ) Pd, 5b). Pt-
(CH3)2(cod) (0.019 g, 0.057 mmol) and 2‚HH (0.032 g, 0.056
mmol) were dissolved in toluene (1 mL) to afford an orange
solution. After ca. 2 h, a yellow solid formed and this mixture was
left to stand for a further 2 days. The solid was collected by suction
filtration and dried in vacuo. Yield: 0.036 g (81%). Selected data
for 5a: 31P (CDCl3): 15.9 ppm, 1J(PPt) 3865 Hz. 1H (CDCl3): 8.65
(m, 3J(HPt) 39.7, 1H, CHdN), 8.14 (d, 3J(HH) 8.3, 1H, arom. H),
7.52-6.84 (m, 22 H, arom. H), 5.90 (s, 1H, NH), 5.09 (s, 2H,
OCH2), 4.29 (d, 3J(HH) 4.3, 2H, NCH2), 0.69 (m, 2J(HPt) 85.8 Hz,
3H, PtCH3) ppm. FT-IR (KBr): 3302 (NH), 1712 (CO), 1616
(Amide I) cm-1. ES-MS: m/z 781 [M+]. Anal. Calcd for C36H32N3O3-
PPt: C, 55.45; H, 4.02; N, 5.39. Found: C, 55.60; H, 4.05; N,
4
3
8.48 (d, J(HH) 8, 1H, arom. H), 8.06 (m, 1H, arom. H), 7.45-
6.91 (m, 21H, arom. H), 5.61 (br, 1H, NH), 5.15 (s, 2H, OCH2),
3
4.20 (d, J(HH) 5.6, 2H, NCH2) ppm. FT-IR (KBr): 3332 (NH),
1721 (CO), 1668 (Amide I), 1538, 1522 (Amide II) cm-1. EI-MS:
m/z 571 [M+]. Anal. Calcd for C35H30N3O3P: C, 73.54; H, 5.30;
N, 7.35. Found: C, 73.38; H, 5.09; N, 7.34.
Preparation of 2-{Ph2P(O)C6H4C(H)dN}C6H4{N(H)COCH2N-
(H)CO2Bz} (2b). Compound 2‚HH (0.103 g, 0.180 mmol) was
dissolved in acetone (10 mL), and aqueous H2O2 (27.5%, 0.1 mL)
was added. The yellow solution was stirred for 80 min and
evaporated to dryness under reduced pressure. The solid was
redissolved in CH2Cl2 (1 mL), and 2b precipitated by addition of
diethyl ether (20 mL) and hexanes (20 mL). The solid was collected
by suction filtration and dried in vacuo. Yield: 0.084 g, 79%.
Selected data: 31P (CDCl3): 32.3 ppm. 1H (CDCl3): 10.55 (s, 1H,
NH), 8.60 (s, 1H, CHdN), 8.46 (d, 3J(HH) 8, 1H, arom. H), 7.97-
t
5.22. Compound 5b was prepared in 96% from 4c and BuOK in
3
6.64 (m, 23H, arom. H and NH), 5.09 (s, 2H, OCH2), 4.33 (d, J-
CH3OH. Selected data for 5b: 31P (CDCl3): 39.8 ppm. 1H
(CDCl3): 8.33 (s, 1H, CHdN), 8.02 (d, 3J(HH) 8.3, 1H, arom. H),
7.59-6.72 (m, 22 H, arom. H), 5.92 (s, 1H, NH), 5.05 (s, 2H,
(HH) 6, 2H, NCH2) ppm. FT-IR (KBr): 3345, 3230 (NH), 1725
(CO), 1684 (Amide I), 1518 (Amide II), 1176 (PO) cm-1. ES-MS:
m/z 588 [M+]. Anal. Calcd for C35H30N3O4P‚0.5H2O: C, 70.45;
H, 5.25; N, 7.04. Found: C, 70.57; H, 5.23; N, 6.70.
3
3
OCH2), 4.15 (d, J(HH) 4.2, 2H, NCH2), 0.39 (d, J(HP) 3.7 Hz,
3H, PdCH3) ppm. FT-IR (KBr): 3287 (NH), 1724 (sh), 1710 (both
CO), 1592 (Amide I) cm-1. ES-MS: m/z 692 [M+]. Anal. Calcd
for C36H32N3O3PPd: C, 62.47; H, 4.67; N, 6.07. Found: C, 62.32;
H, 4.58; N, 6.11.
Preparation of AuCl(2‚HH) (3). AuCl(tht) (0.0086 g, 0.0268
mmol) and 2‚HH (0.0154 g, 0.0269 mmol) were dissolved in CH2-
Cl2 (0.5 mL) to afford a yellow solution. Diethyl ether was allowed
to vapor diffuse into this solution over ca. 14 d to give yellow
crystals which were collected by suction filtration and dried in
vacuo. Yield: 0.020 g (93%). Selected data: 31P (CD2Cl2): 28.8
Preparation of M(2) (M ) Pt, anti-6a\syn-6a′; M ) Pd, anti-
6b\syn-6b′). Method 1. A CH3OH (15 mL) solution of 4a (0.052
t
g, 0.062 mmol) and BuOK (0.029 g, 0.258 mmol) were refluxed
1
ppm. H (CD2Cl2): 8.97 (s, 1H, CHdN), 8.62 (s, 1H, NH), 8.22
for 3 h. The orange solution was cooled and evaporated to dryness.
The residue was extracted into CH2Cl2 (25 mL) and passed through
a small Celite plug, and the volume concentrated under reduced
pressure to ca. 1-2 mL. Addition of diethyl ether (10 mL) and
petroleum ether (bp 60-80 °C, 10 mL) gave anti-6a\syn-6a′.
Yield: 0.047 g (97%). Compound anti-6b\syn-6b′ was similarly
prepared from 4b (75%). Selected data for anti-6a\syn-6a′: 31P
3
(d, J(HH) 8.4, 1H, arom. H), 8.16 (s, 1H, arom. H), 7.58-6.86
3
(m, 21H, arom. H), 6.32 (d, J(HH) 8.8, 1H, arom. H), 5.67 (br,
1H, NH), 4.89 (s, 2H, OCH2), 3.88 (d, 3J(HH) 6, 2H, NCH2) ppm.
FT-IR (KBr): 3331, 3290 (NH), 1722 (CO), 1664 (Amide I), 1536
(sh), 1522 (both Amide II), 330 (AuCl) cm-1. ES-MS: m/z 768
[M-Cl]. Anal. Calcd. for C35H30AuClN3O3P: C, 52.28; H, 3.77;
N, 5.23. Found: C, 52.39; H, 3.66; N, 5.09.
1
(CDCl3, 295 K): 12.3, 12.0 ppm, J(PPt) 3492, 3508 Hz (ca. 1:1
1
ratio). H (CDCl3, 295 K): 8.95-8.53 (m, arom. H), 7.96-6.90
Preparation of ML2(2‚HH) (M ) Pt, L2 ) Cl2, 4a; M ) Pd,
L2 ) Cl2, 4b; M ) Pd, L ) Cl, CH3, 4c). PtCl2(cod) (0.064 g,
0.171 mmol) was dissolved in CH2Cl2 (20 mL). To this solution
2‚HH (0.099 g, 0.173 mmol) was added to give an immediate
orange solution. After the mixture was stirred for 30 min, the
volume was reduced under vacuum to ca. 1-2 mL and addition of
diethyl ether (30 mL) afforded an orange solid. This was collected
by suction filtration and dried in vacuo. Yield: 0.119 g (80%).
Compound 4b was similarly prepared from PdCl2(cod) (98%).
Selected data for 4a: 31P (CDCl3/CH3OH): 4.2 ppm, 1J(PPt) 3737
(m, arom. H), 4.80 (s), 4.70 (s), 4.66 (s), 3.90 (s) (all CH2) ppm.
1H (CDCl3, 333 K): 8.87 (d, 3J(HH) 8.4, 1H, arom. H), 8.82 (m,3-
(HPt) 80, 1H, CHdN), 8.14-6.89 (m, 22H, arom. H), 4.70 (m,
3J(HPt) 27.2, 2H, NCH2), 4.52 (br, 2H, OCH2). FT-IR (KBr): 1656
(CO), 1624 (Amide I) cm-1. ES-MS: m/z 765 [M+]. Anal. Calcd
for C35H28N3O3PPt‚H2O: C, 53.71; H, 3.87; N, 5.37. Found: C,
53.30; H, 3.71; N, 5.32. Selected data for anti-6b\syn-6b′: 31P
1
(CDCl3, 295 K): 26.5, 26.3 ppm (ca. 1:1 ratio). H (CDCl3, 295
K): 8.60-8.43 (m, arom. H), 7.86-6.79 (m, arom. H), 4.61 (s),
1
3
1
4.55 (s), 3.85 (s) (all CH2) ppm. H (CDCl3, 333 K): 8.67 (d, J-
(HH) 7.6, 1H, arom. H), 8.53 (s, 1H, CHdN), 7.84-6.81 (m, 22H,
arom. H), 4.55 (s, 2H, NCH2), 4.38 (br, 2H, OCH2). FT-IR (KBr):
1640 (CO), 1614 (Amide I) cm-1. ES-MS: m/z 676 [M+]. Anal.
Calcd for C35H28N3O3PPd: C, 62.18; H, 4.18; N, 6.22. Found: C,
61.75; H, 3.96; N, 6.18.
Hz. H (CD3SOCD3): 9.23 (s), 9.19 (s), 8.83 (s), 8.24-6.83 (m,
arom. H), 4.99 (s), 4.94 (s), 4.22 (s) ppm. FT-IR (KBr): 3366,
3348 (NH), 1721 (CO), 1685 (Amide I), 1506 (Amide II), 290,
280 (PtCl) cm-1. ES-MS: m/z 766 [M - 2Cl]. Anal. Calcd for
C35H30Cl2N3O3PPt: C, 50.18; H, 3.62; N, 5.02. Found: C, 49.91;
H, 3.63; N, 4.97. Selected data for 4b (CDCl3/CH3OH): 31P: 30.6
ppm. 1H (CD3SOCD3): 9.23 (s), 8.59 (s), 8.13 (s), 7.91-6.63 (m,
arom. H), 4.97 (s), 3.67 (s) ppm. FT-IR (KBr): 3328 (NH), 1717
Method 2. To an orange CH2Cl2 (7 mL) solution of Pd(OAc)2
(0.043 g, 0.192 mmol) was added 2‚HH (0.110 g, 0.192 mmol).
Inorganic Chemistry, Vol. 46, No. 7, 2007 2757