Organometallics
Article
Complex (3b) [C38H54FeN8Zr]. Proligand 1b (100 mg, 0.2 mmol)
was dissolved in hexanes (0.25 mL), supplemented with Zr(NMe2)4
(54 mg, 0.2 mmol), and gently shaken until homogeneous. After 1
day, crystalline residue deposited in the bottom of the vial. The
supernatant was removed, and the orange colored crystals were
washed with hexanes (3 × 0.1 mL) and dried under vacuum to obtain
3b. Yield (56 mg, 37%). 1H NMR (400 MHz, Toluene-d8) δ 6.73 (s,
4H, Aryl-H), 4.34 (t, J = 1.9 Hz, 4H, Cp-H), 3.91−3.84 (t, J = 1.9 Hz,
4H, Cp-H), 2.85 (s, 12H, Zr−N(CH3)2), 2.33 (s, 12H, Aryl-CH3),
2.17 (br, 12H, guanidinate-N(CH3)2), 2.14 (br, 6H, Aryl-CH3). 13C
NMR (101 MHz, Toluene-d8) δ 168.8 (guanidinate-C), 144.6 (Cq),
137.5 (Cq), 132.5 (Cq), 131.6 (Cq), 129.2 (Aryl-CH), 109.5 (Cp-C-
N), 64.0 (Cp-CH), 64.0 (Cp-CH), 44.3 (Zr−N(CH3)2), 38.3
(guanidinate-N(CH3)2), 20.9 (Aryl-CH3), 19.2 (Aryl-CH3). FT-IR
(ATR, cm−1) 3088, 2912, 2855, 1621, 1600, 1532, 1472, 1393, 1372,
1273, 1198, 1144, 1159, 1022, 1003, 941, 880, 855, 814, 798, 762,
737, 683, 629, 582, 517, 490. Melting Point: 274 °C. Elemental
Analysis Anal. Found: C, 59.49; H, 7.01; N, 14.41. Calcd
[C38H54FeN8Zr]: C, 59.28; H, 7.07; N, 14.55.
Complex (3c) [C44H66FeN8Zr]. In a vial, proligand 1c (100 mg,
0.17 mmol) was dissolved in hexanes (0.2 mL). Solid Zr(NMe2)4 (46
mg, 0.17 mmol) was added, and the mixture was left to stand
overnight upon which a crystalline residue was obtained. The
supernatant was removed, and the crystals were washed with hexanes
(3 × 0.1 mL) and dried under vacuum to obtain 3c. Yield (76 mg,
47%). 1H NMR (600 MHz, Toluene-d8, 90 °C) δ 4.24−4.18 (m, 4H,
Cp-H), 3.92−3.87 (m, 4H, Cp-H), 3.65 (hept, J = 1.8 Hz, 4H, Aryl-
CH(CH3)2), 2.81−2.80 (m, 12H, Zr−N(CH3)2), 2.35 (br, 12H,
guanidinate-N(CH3)2), 1.33 (m, 24H, Aryl-CH(CH3)2). 13C NMR
(151 MHz, Toluene-d8, 90 °C) δ 168.2 (guanidinate-C), 143.9 (Cq),
143.5 (Cq), 125.2 (Aryl-CH), 123.8 (Aryl-CH), 111.4 (Cp-C-N), 64.3
(Cp-CH), 62.7 (Cp-CH), 44.4 (Zr−N(CH3)2), 39.7 (guanidinate-
N(CH3)2), 28.0 (Aryl-CH(CH3)2), 24.9 (Aryl−CH(CH3)2), 24.9
(Aryl−CH(CH3)2). FT-IR (ATR, cm−1) 3056, 2956, 2864, 2763,
1622, 1584, 1530, 1459, 1434, 1377, 1358, 1339, 1296, 1238, 1200,
1181, 1157, 1130, 1109, 1055, 1013, 933, 891, 816, 786, 768, 758,
700, 661, 631, 592, 524, 487, 438, 420. Melting Point: 260−261 °C
Elemental Analysis Anal. Found: C, 62.07; H, 8.00; N, 13.12. Calcd
[C44H66FeN8Zr]: C, 61.87; H, 7.79; N, 13.12.
supernatant was removed, and the residue was washed with additional
toluene (0.15 mL) and dried under vacuum to obtain 4a. Yield (115
1
mg, 63%). H NMR (400 MHz, Toluene-d8) δ 4.35 (br, 2H, Cp-H),
3.93 (br, 4H, Cp-H), 3.85 (br, 2H, Cp-H), 3.53 (br, 6H, Hf−
N(CH3)2), 3.21 (br, 6H, Hf−N(CH3)2), 2.48 (s, 12H, guanidinate-
N(CH3)2), 1.42 (s, 18H, −C(CH3)3). 13C NMR (101 MHz, Toluene-
d8) δ 170.7 (br, guanidinate-C), 106.0 (br, Cp-C-N), 65.6 (Cp-CH),
63.8 (Cp-CH), 53.8 (br, −C(CH3)3), 46.5 (Hf−N(CH3)2), 46.2
(Hf−N(CH3)2), 41.1 (br, guanidinate-N(CH3)2), 32.2 (−C(CH3)3).
FT-IR (ATR, cm−1) 3097, 3078, 2965, 2851, 2801, 2753, 1605, 1525,
1477, 1446, 1425, 1388, 1355, 1282, 1238, 1213, 1198, 1185, 1137,
1121, 1069, 1056, 1010, 959, 946, 923, 909, 836, 821, 799, 786, 764,
726, 685, 636, 617, 510, 487, 436. Melting Point: 222−223 °C.
Elemental Analysis Anal. Found: C, 45.46; H, 6.59; N, 15.00. Calcd
[C28H50FeN8Hf]: C, 45.87; H, 6.87; N, 15.29.
Complex (4b) [C38H54FeN8Hf]. Identical procedure for 3b using
Hf(NMe2)4 as the metal source. Yield of orange crystals (45 mg,
1
27%). H NMR (400 MHz, Toluene-d8) δ 6.73 (s, 4H), 4.31 (t, J =
2.0 Hz, 4H, Cp-H), 3.88 (t, J = 2.0 Hz, 4H, Cp-H), 2.89 (s, 12H, Hf−
N(CH3)2), 2.35 (s, 12H, (Aryl−CH3), 2.17 (br, 12H, guanidinate-
N(CH3)2)), 2.15 (s, 6H, Aryl−CH3). 13C NMR (101 MHz, Toluene-
d8) δ 168.1 (guanidinate-C). 143.9 (Cq), 132.9 (Cq), 131.9 (Cq),
129.1 (Aryl-CH), 108.6 (Cp-C-N), 64.2 (Cp-CH), 64.1 (Cp-CH),
44.2 (Hf−N(CH3)2), 38.3 (guanidinate-N(CH3)2), 20.8 (Aryl-CH3),
19.1 (Aryl-CH3). FT-IR (ATR, cm−1) 3090, 2913, 2856, 2810, 2760,
1624, 1603, 1534, 1474, 1438, 1402, 1222, 1200, 1022, 1152, 1063,
1011, 946, 882, 851, 837, 813, 799, 764, 734, 683, 632, 615, 584, 554,
518, 499, 450, 433, 413. Melting Point: 268 °C. Elemental Analysis
Anal. Found: C, 52.32; H, 6.41; N, 12.54. Calcd [C38H54FeN8Hf]: C,
53.24; H, 6.35; N, 13.07.
Complex (4c) [C44H66FeN8Hf]. Same procedure as that for 1c
using Hf(NMe2)4 as the metal source. The title compound
crystallized as large orange crystalline chunks. Yield (111 mg, 69%).
1H NMR (600 MHz, Toluene-d8, 90 °C) δ 4.19 (t, J = 1.9 Hz, 4H,
Cp-H), 3.89 (t, J = 1.8 Hz, 4H, Cp-H), 3.70 (hept, J = 6.9 Hz, 4H,
Aryl-CH(CH3)2), 2.85 (s, 12H, Hf−N(CH3)2), 2.36 (s, 12H,
guanidinate-N(CH3)2), 1.35 (d, J = 6.8 Hz, 12H, Aryl-CH(CH3)2),
1.33 (d, J = 6.8 Hz, 12H, Aryl-CH(CH3)2). 13C NMR (151 MHz,
Toluene-d8) δ 167.7 (guanidinate-C), 143.8 (Cq), 143.3 (Cq), 125.5
(Aryl-CH), 123.8 (Aryl-CH), 110.6 (Cp-C-N), 64.3 (Cp-CH), 62.7
(Cp-CH), 44.5 (Zr−N(CH3)2), 28.0 (guanidinate-N(CH3)2), 25.0
(Aryl-CH(CH3)2), 24.9 (Aryl-CH(CH3)2). FT-IR (ATR, cm−1) 3058,
2956, 2866, 1620, 1584, 1529, 1458, 1434, 1376, 1326, 1273, 1252,
1234, 1199, 1142, 1107, 1057, 1021, 1000, 935, 792, 751, 701, 627,
484. Melting Point: 275−276 °C. Elemental Analysis Anal. Found: C,
56.31; H, 7.30; N, 11.90. Calcd [C44H66FeN8Hf]: C, 56.14; H, 7.07;
N, 11.90.
Complex 4d [C40H62FeN8Hf]. Proligand 1d (60 mg, 0.11 mmol)
was dissolved in tetrahydrofuran (0.3 mL), solid Hf(NMe2)4 (40 mg,
0.11 mmol) was added, and the vial was shaken until homogeneous.
Yellow crystals deposit overnight. The supernatant was removed, and
the crystalline residue was washed with tetrahydrofuran (3 × 0.1 mL)
and dried under vacuum to obtain 4d. Yield (56%, 56 mg). 1H NMR
(400 MHz, Toluene-d8, 233 K) δ 4.45 (s, 1H, Cp-H), 4.40 (s, 1H,
Cp-H), 4.08 (s, 1H, Cp-H), 4.02 (s, 1H, Cp-H), 3.95 (s, 1H, Cp-H)
3.91 (s, 1H, Cp-H), 3.89 (s, 1H, Cp-H), 3.87 (s, 1H), 3.64 (m, 6H,
Hf−N(CH3)2), 3.32 (s, 6H, Hf−N(CH3)2), 2.61 (s, 3H, guanidinate-
N(CH3)2), 2.47 (s, 6H, guanidinate-N(CH3)2), 2.24−2.10 (m, 18H,
guanidinate-N(CH3)2 + −CH2− + −CH−), 1.96−1.93 (m, 3H,
−CH2−), 1.78−1.66 (m, 12H, −CH2−). 13C NMR (101 MHz,
Toluene-d8, 233 K) δ 171.7 (guanidinate-C), 169.1 (guanidinate-C),
106.8 (Cp-C-N), 105.0 (Cp-C-N), 68.2 (Cp-CH), 65.9 (Cp-CH),
65.5 (Cp-CH), 64.6 (Cp-CH), 63.6 (Cp-CH), 63.1 (Cp-CH), 59.5
(Cp-CH), 55.7 (N-C-Adamantyl), 53.7 (N-C-Adamantyl), 47.2 (Hf−
N(CH3)2), 46.8 (Hf−N(CH3)2), 46.3 (Hf−N(CH3)2), 45.1
(−CH2−), 44.5 (guanidinate-N(CH3)2), 42.9 (−CH2−), 41.7 (br,
guanidinate-N(CH3)2), 40.0 (guanidinate-N(CH3)2), 39.4 (br,
guanidinate-N(CH3)2), 37.1 (−CH2−), 36.9 (−CH2−), 30.7
(−CH−), 30.2 (−CH−). FT-IR (ATR, cm−1) 2902, 2848, 2804,
2757, 2742, 1601, 1533, 1516, 1477, 1462, 1446, 1425, 1407, 1390,
Complex 3d [C40H62FeN8Zr]. Proligand 1d (46 mg, 0.09 mmol)
was dissolved in tetrahydrofuran (0.2 mL), supplemented with solid
Zr(NMe2)4 (23 mg, 0.09 mmol), and gently shaken until
homogeneous. Upon standing overnight the product crystallized.
The supernatant was removed, and the crystals were washed with
tetrahydrofuran (3 × 0.1 mL) and dried under vacuum to obtain 3d.
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Yield (77%, 53 mg). H NMR (400 MHz, Toluene-d8, −80 °C) δ
4.52 (br, 1H, Cp-H), 4.45 (br, 1H, Cp-H), 4.17 (br, 1H, Cp-H), 4.05
(br, 1H, Cp-H), 4.02, (br, 1H, Cp-H), 3.97 (br, 1H, Cp-H), 3.93 (br,
2H, Cp-H), 3.68 (br, 3H, guanidinate-N(CH3)2), 3.61 (br, 3H,
guanidinate-N(CH3)2), 3.33 (br, 6H, guanidinate-N(CH3)2), 2.58
(br, 3H, Zr−N(CH3)2), 2.43 (br, 3H, Zr−N(CH3)2), 2.34 (br, 3H,
Zr−N(CH3)2), 2.24−1.65 (m, 47H). 13C NMR (101 MHz, Toluene-
d8, 193 K) δ 171.8 (guanidinate-C), 169.6 (guanidinate-C), 107.4
(Cp-C-N), 106.4 (Cp-C-N), 67.9 (br, Cp-CH), 67.7 (Cp-CH), 66.0
(br, Cp-CH), 65.8 (br, Cp-CH), 64.6 (br, Cp-CH), 64.2 (Cp-CH),
63.8 (Cp-CH), 63.1 (Cp-CH), 59.0 (Cp-CH), 56.0 (N-C-
Adamantyl), 53.7 (N-C-Adamantyl), 47.3 (Zr−N(CH3)2), 45.0
(−CH2−), 44.6 (Zr−N(CH3)2), 41.6 (guanidinate-N(CH3)2), 39.7
(guanidinate-N(CH3)2), 39.2 (guanidinate-N(CH3)2), 36.9
(−CH2−), 36.7 (−CH2−), 30.5 (−CH−), 30.0 (−CH−). FT-IR
(ATR, cm−1) 2972, 2901, 2844, 2801, 2753, 1605, 1526, 1462, 1429,
1408, 1378, 1352, 1342, 1304, 1274, 1260, 1235, 1219, 1192, 1181,
1119, 1095, 1056, 1007, 979, 957, 922, 840, 815, 794, 759, 714, 695,
640, 617, 580, 515, 477, 422, 407. Melting Point: 237−238 °C.
Elemental Analysis Anal. Found: C, 59.81; H, 7.64; N, 13.72. Calcd
[C40H62FeN8Zr]: C, 59.90; H, 7.79; N, 13.97.
Complex (4a) [C28H50FeN8Hf]. Proligand 1a (95 mg, 0.25 mmol)
was dissolved in toluene (0.5 mL), and Hf(NMe2)4 (89 mg, 0.25
mmol) was added. The vial was shaken until homogeneous and
allowed to stand for 4 h until crystalline material formed. The
H
Organometallics XXXX, XXX, XXX−XXX