2082 J. Am. Chem. Soc., Vol. 120, No. 9, 1998
Johnson et al.
mixture was stirred overnight, subsequent to which the OEt2 was
removed in vacuo. The residue was extracted with pentane, the extract
was filtered, and the crude material thereby obtained was recrystallized
from OEt2 (3 mL) at -35 °C (0.2865 g, 0.4245 mmol, 63%): mp 110-
112 °C (dec). 2H NMR (46 MHz, OEt2): δ ) 6.545 (∆ν1/2 ) 22.0
Hz). 1H NMR (300 MHz, C6D6): δ ) ≈6.0 (br s, 1), -1.1 (br s, 3).
IR (benzene/KBr): ν(MoS) ) 491 cm-1. EPR (toluene, 25 °C): g )
1.96, a(95Mo/97Mo) ) 28.5 G. EPR (toluene, 107 K): g1 ) 1.996, g2
) 1.970, g3 ) 1.922, a3(95Mo/97Mo) ) 54 G. MS (70 eV) m/z (%):
671 (0.22) [M+]. µeff ) 1.630 µB. CV (CH2Cl2/[N(n-Bu)4][PF6]): E1/2
) -0.73 V. Anal. Calcd for C36H42D12MoN3S: C, 64.64; H, 8.14;
N, 6.28. Found: C, 64.94; H, 8.31; N, 6.23.
°C in a sealed bomb for 25 h. The solution changed from dark brown
to red-brown. The benzene was removed in vacuo, and an orange
powder was obtained from OEt2 (0.1250 g, 0.2043 mmol, 84.1%): mp
183-4 °C. 1H NMR (300 MHz, C6D6): δ ) 7.204 (s, 5); 7.15 (s, 4);
6.710 (s, 9); 6.587 (s, 10); 2.145 (s, 3); 2.041 (s, 6H, 11); 1.310 (s,
6H, 1). 13C NMR (75 MHz, CDCl3): δ ) 157.545 (s, 12); 151.53 (s,
7); 138.27 (s, 13); 137.87 (s, 8); 129.77 (d, 4 or 9); 128.60 (br d, 4 or
9); 127.711 (d, 5 or 10); 119.87 (d, 5 or 10); 62.385 (s, 6); 31.957 (q,
1); 31.447 (m, 2); 21.481 (q, 3 and 11). IR (benzene/KBr): ν(MoS)
) 506 cm-1. MS (70 eV) m/z (%): 613 (44.1) [M+]. Anal. Calcd
for C32H33D12MoN3S: C, 62.82; H, 7.41; N, 6.87. Found: C, 63.11;
H, 7.56; N, 6.76.
4.6. Synthesis of Mo(Se)(N[R]Ar)3. Solid Mo(N[R]Ar)3 (0.5008
g, 0.7790 mmol) and Se (0.0810 g, 0.790 mmol) were added to a vessel
containing OEt2 (10 mL), and the resulting mixture was stirred for 11
h. The solution was filtered to remove excess Se, and the filtrate was
concentrated. Three crops of crystals were collected subsequent to
recrystallization from OEt2 at -35 °C (0.4519 g, 0.6260 mmol,
80.4%): mp 128-130 °C. 1H NMR (300 MHz, C6D6): δ ≈ 6.5 (br
s, 1), -1.412 (br s, 3). 2H NMR (46 MHz, OEt2): δ ) 7.036 (∆ν1/2
) 30.7 Hz). IR (benzene/polyethylene): ν(MoSe) ) 342 cm-1. EPR
(toluene, 25 °C): g ) 1.97, a(95Mo/97Mo) ) 30.5 G. EPR (toluene,
98 K): g1 ) 2.030, a1(95Mo/97Mo) ) 29 G, g2 ) 1.986, g3 ) 1.899,
a3(95Mo/97Mo) ) 48 G. UV/vis (ether): λmax ) 403 nm (ꢀ 6270); 487
nm (ꢀ 2410). MS (70 eV) m/z (%): 658.2 (18.11) [M+ - C(CD3)2-
CH3]. SQUID (5-300 K): 1.75 µB. CV (CH2Cl2/[N(n-Bu)4][PF6]):
E1/2 ) -0.64 V. Anal. Calcd for C36H36D18MoN3Se: C, 59.90; H,
7.54; N, 5.82. Found: C, 60.25; H, 7.41; N, 5.68.
4.11. Synthesis of Mo(Se)(NAr)(N[R]Ar)2. Mo(Se)(N[R]Ar)3
(0.6377 g, 0.8834 mmol) and C6H6 (30 mL) were loaded into a sealable
glass bomb and evacuated to autogenic pressure. The mixture was
heated at 65 °C for 22 h at which point the solution had changed from
the dark brown initial color to red-orange. The benzene was removed
in Vacuo, and the product was precipitated from OEt2 (∼15 mL) as a
finely divided orange brown powder in 2 crops (0.3733 g, 0.5667 mmol,
64%): mp 201.5-202 °C. 1H NMR (300 MHz, C6D6): δ ) 7.304 (s,
9); 7.15 (s, 4); 6.713 (s, 5); 6.601 (s, 10); 2.145 (s, 3); 2.052 (s, 11);
1.290 (s, 1). 13C NMR (75 MHz, CDCl3): δ ) 157.243 (s, 12); 150.940
(s, 7); 138.027 (q, 13); 137.613 (q, 8); 129.454 (d); 128.612 (br m, 4);
127.438 (d); 119.225 (d); 62.20 (s, 6); 31.517 (q, 1); 31.0 (m, 2); 21.101
(q, 3 and 11). 77Se NMR (57.292 MHz, CDCl3, pw ) 15 ms, d1 ) 1
s, 16000 scans): δ ) 1923.4 (∆ν1/2 ) 46.2 Hz) relative to Me2Se. IR
(benzene/polyethylene): ν(MoSe) ) 355 cm-1. UV/vis (ether): λmax
) 292 nm (ꢀ 17700). MS (70 eV) m/z (%): 660 (5) [M+]. Anal. Calcd
for C32H33D12MoN3Se: C, 58.35; H, 6.89; N, 6.38. Found: C, 58.79;
H, 6.94; N, 6.24.
4.12. Synthesis of Mo(Te)(NAr)(N[R]Ar)2. Mo(Te)(N[R]Ar)3
(0.5085 g, 0.6600 mmol) was dissolved in C6H6 (25 mL) and evacuated
to autogenic pressure. The solution was heated at 65 °C for 5 h; no
color change was observed. The C6H6 was removed in vacuo leaving
a fine dark red-brown powder (0.3712 g, 0.5248 mmol, 80%) which
was contaminated with about 5% HN(R)Ar. The complex can be
recrystallized from OEt2 in low yield (∼40%): mp 194.5-195.5 °C.
1H NMR (300 MHz, CDCl3): δ ) 7.3 (br s, 4); 7.032 (s, 5 or 9);
6.916 (s, 10); 6.886 (s, 5 or 9); 6.4 (br s, 4); 2.350 (s, 11); 2.278 (s, 3);
1.131 (s, 1). 13C NMR (75 MHz, CDCl3): δ ) 157.624 (s, 12); 149.799
(s, 7); 138.412 (q, 13); 137.947 (q, 8); 131.2 (br d, 4); 129.548 (d);
127.776 (d); 127.0 (br d, 4); 119.116 (d); 62.6735 (s, 6); 31.4322 (q,
1); 30.9061 (m, 2); 21.2830 (q, 3); 21.2226 (q, 11). 125Te NMR (158
MHz, CDCl3, pw ) 12 ms, d1 ) 1 s, 28000 scans): δ: 2459.3 (∆ν1/2
) 250 Hz). IR (benzene/polyethylene): ν(MoTe) ) 291 cm-1. UV/
vis (OEt2): λmax ) 327 nm (ꢀ 13 700). MS (70 eV) m/z (%): 705.2
(70) [M+]. Anal. Calcd for C32H33D12MoN3Te: C, 54.34; H, 6.41;
N, 5.94. Found: C, 51.30; H, 6.42; N, 5.39.
4.7. Reaction of Mo(N[R]Ar)3 with PEt3. Solid Mo(N[R]Ar)3
(0.0503 g, 0.0782 mmol) was dissolved in OEt2 (2 mL), and PEt3 (15
µL, 0.102 mmol, 1.3 eq) was added. The reaction mixture was stirred
for 18 h and then examined by 2H NMR. The spectrum revealed only
the presence of unreacted Mo(N[R]Ar)3.
4.8. Synthesis of Mo(Te)(N[R]Ar)3. Solid Mo(N[R]Ar)3 (0.5035
g, 0.7832 mmol) and Te (0.1188 g, 0.9310 mmol) were added to a
vessel containing OEt2 (10 mL) leading to an orange solution. PEt3
(20 µL, 0.14 mmol, 0.17 equiv) was then added, and the reaction
mixture was stirred for 18 h, during which time the mixture acquired
a dark brown color. The OEt2 was removed in vacuo, the resulting
residue was extracted with THF, and the extract was filtered and
concentrated. Recrystallization from OEt2 (ca. 25 mL) at -35 °C
produced spectroscopically pure Mo(Te)(N[R]Ar)3 (2 crops, 0.4422 g,
0.5739 mmol, 73%): mp 127-128 °C (dec.). 2H NMR (46 MHz,
ether): δ ) 8.120 (∆ν1/2 ) 22.9 Hz). 1H NMR (300 MHz, ether): δ
) 8.120 (∆ν1/2 ) 22.9 Hz). 1H NMR (300 MHz, C6D6): δ ≈ 8 (br S,
1), -1.9 (br s, 3). IR (benzene/polyethylene): ν(MoTe) ) 286 cm-1
.
EPR (toluene, 25 °C): g ) 1.977. EPR (toluene, 105 K): g1 ) 2.130,
a1(95Mo/97Mo) ) 28 G, g2 ) 1.970, a2(95Mo/97Mo) ) 24 G, g3 ) 1.850,
a3(95Mo/97Mo) ) 48 G. UV/vis (ether): λmax ) 486 nm (ꢀ ) 6314).
MS (70 eV) m/z (%): 707.3 (38.24) [M+ - C(CD3)2CH3]. SQUID
(5-180 K): 1.86 µB. CV (CH2Cl2/[N(n-Bu)4][PF6]): E1/2 ) -0.63
V. Anal. Calcd for C36H42D12MoN3Te: C, 56.12; H, 7.06; N, 5.45.
Found: C, 56.50; H, 7.33; N, 5.17.
4.13. Synthesis of [Mo(O)(N[R]Ar)3][O3SCF3]. Mo(O)(N[R]Ar)3
(0.0996 g, 0.1512 mmol) in OEt2 was added to a slurry of [Cp2Fe]-
[O3SCF3] (0.0512 g, 0.1528 mmol) in OEt2 to a total volume of 5 mL.
The solution was stirred for 15 h, at which point the solution was brown
and an orange brown precipitate was observed. The solid (0.0865 g,
0.1071 mmol, 71%) was collected on a frit and washed with ether; the
washings were colorless: mp 100-101 °C (dec.). 1H NMR (300 MHz,
CDCl3): δ ) 7.094 (s, 5); 5.5 (br s, 4); 2.221 (br s, 3); 1.428 (br s, 1).
19F NMR (282 MHz, CDCl3): δ ) -83.417. 13C NMR (125 MHz,
CDCl3): 148.083, 139.397, 131.501, 125.394 (4), 70.547 (6), 31.227
(1), 30.739 (2), 21.564 (3). IR (Nujol/KBr): 1601.8, 1266.1 (ionic
triflate),46 1221.8, 1146.4, 1111.1, 1031.1 (ionic triflate),46 971.8 (ν-
4.9. Synthesis of Mo(O)(NAr)(N[R]Ar)2. A solution of Mo(O)-
(N[R]Ar)3 (0.4422 g, 0.6879 mmol) in C6H6 (10 mL) was heated (65
°C) until the dark brown color, characteristic of Mo(O)(N[R]Ar)3, faded
to a much lighter yellow (ca. 5 d). Solvent was removed in vacuo,
yielding, essentially quantitatively by weight, a yellow oil. 1H NMR
spectroscopy indicated the oil to consist of Mo(O)(NAr)(N[R]Ar)2
(approximately 85% pure, contaminated with HN(R)Ar). 1H NMR (300
MHz, C6D6): δ ) 6.912 (s, 4); 6.885 (s, 5); 6.712 (s, 9); 6.52 (s, 10);
2.139 (s, 3); 2.026 (s, 11); 1.340 (s, 1). 13C NMR (75 MHz, CDCl3):
δ ) 6.912 (s, 4); 6.885 (s, 5); 6.712 (s, 9); 6.52 (s, 10); 2.139 (s, 3);
2.026 (s, 11); 1.340 (s, 1). 13C NMR (75 MHz, CDCl3): δ ) 156.365
(s, 12); 150.510 (s, 7); 137.712 (s, 13); 137.560 (s, 8); 128.304 (d, 4);
127.373 (d, 9); 120.702 (d, 10); 120.008 (d, 5); 60.555 (s, 6); 31.496
(q, 1); 30.090 (m, 2); 21.237 (q, 3); 21.143 (q, 11). IR (benzene/
KBr): ν(MoO) ) 913 cm-1. MS (70 eV) m/z (%): 594.3 (1.77) [M+].
HRMS (70 eV): calcd mass (597.336989); found (597.33709).
4.10. Synthesis of Mo(S)(NAr)(N[R]Ar)2. Mo(S)(N[R]Ar)3 (0.1640
g, 0.2430 mmol) was dissolved in benzene (10 mL) and heated at 62.5
MoO), 698.8, 637.3, 570.7, 474.0 cm-1
.
Anal. Calcd for
C37H36D18F3MoN3O4S: C, 55.00; H, 6.74; N, 5.20. Found: C, 56.67;
H, 6.94; N, 4.89.
4.14. Synthesis of [Mo(O)(N[R]Ar)3][I]. To a solution of Mo(O)-
(N[R]Ar)3 (0.0999 g, 0.1516 mmol) in OEt2 was added iodine (0.0199
g, 0.0784 mmol, 0.52 equiv) in OEt2 giving a total volume of 5 mL.
An orange precipitate formed rapidly. The solution was stirred for 15
h, at which point the supernatant was colorless. The orange solid
(0.1042 g, 0.1326 mmol, 87.5%) was collected on a frit and washed
with ether; the washings were colorless. The complex decomposed
fairly rapidly in solvents in which it was soluble, precluding charac-