Bis(arylimido) Molybdenum(VI) Amidinate and Guanidinate Complexes
lithium salts of amidinate and guanidinate [3 a, 5 a] were pre-
pared by literature methods.
(20 mL) and was added dropwise to a solution of 1 (2.23 g,
3.68 mmol) in THF (20 mL) at ±57 °C. Yield: 1.90 g (69%).
M. p. 120±124 °C.
C37H57ClMoN4Si2 (745.45 g/mol)
Analyses: C 60.08 (calc. 59.62); H 7.98 (7.31); N 7.41
(7.59)%.
Elemental analyses were performed by the Analytisches
Labor des Instituts fuÈr Anorganische Chemie der UniversitaÈt
GoÈttingen. Finnigan MAT 8230 was used for mass spectra
(EI 70 eV). Bruker AM 200 and Bruker 250 spectrometers
1
were used to record H NMR (200.131 MHz) and 29Si NMR
1H NMR (200 MHz, C6D6 solution): d (ppm) = 6.85±7.30 (m, 11 H, 2,6-i-
Pr2C6H3 and C6H5), 4.08 (m, 4 H, CHMe2), 1.33 (d, 12 H, CHMe2), 1.25
(d, 12 H, CHMe2), 0.26 (s, 9 H, SiMe3), 0.12 (2, 9 H, SiMe3).
(99.362 MHz) spectra. The chemical shifts were externally
referenced to SiMe4. Melting points were measured in sealed
glass tubes and were not corrected.
MS (98Mo): m/z (%) = 746(10) [M+]; 571(15) [M+±ArN], 175(100)
[ArN].
[(2,6-i-Pr2C6H3N)2MoCl{N(Cy)C(Me)N(Cy)}] (2).
[N(C6H11)C(Me)N(C6H11)]Li ´ O(C2H5)2 (1.5 g, 5.0 mmol)
was added in serveral portions to a solution of 1 (3.0 g,
5.0 mmol) in THF (35 mL) at ±78 °C. After warming slowly
to ambient temperature (about 2 h), the solution was stirred
at 22 °C for 48 h. After removal of all the volatiles, the resi-
due was extracted with toluene (20 mL). Removing the to-
luene from the extract, washing the residue with ether
(20 mL) and drying the residue in vacuo for 2 h, resulted in
a yellow powder (1.2 g, 40%). M. p. 218±222 °C.
[(2,6-i-Pr2C6H3N)2MoMe{N(Cy)C(Me)N(Cy)}] (6). MeLi
(0.34 mL, 0.54 mmol, 1.6 M solution in ether) was added
dropwise to a solution of 2 (0.37 g, 0.52 mmol) in THF
(20 mL) at ±57 °C. After warming slowly to ambient tem-
perature, the solution was stirred at 22 °C for 16 h. After re-
moval of all the volatiles, the residue was extracted with to-
luene (40 mL). After concentration and cooling to ±32 °C for
several days, orange crystals were formed (0.26 g, 73%).
M. p. 190±195 °C.
C38H59ClMoN4 (703.30 g/mol)
C39H62MoN4 (682.88 g/mol)
Analyses:
C 64.64
(calc
64.90);
H 8.45
(8.46);
Analyses: C 68.13 (calc 68.60); H 9.12 (9.15); N 7.88
(8.20)%.
N 7.97(7.97)%.
1H NMR (200 MHz, C6D6 solution): d (ppm) = 6.90±7.10 (m, 6 H, 2,6-i-
Pr2C6H3), 4.00 (m, 4 H, CHMe2), 3.30 (m, 2 H, Cy), 1.60 (s, 3 H,
NC(CH3)N), 1.1±2.5 (m, 20 H, Cy), 1.24 (d, 12 H, CH(CH3)2), 1.18 (d,
12 H, CH(CH3)2).
1H NMR (200 MHz, C6H6 solution): d (ppm) = 6.85±7.10 (m, 6 H, 2,6-i-
Pr2C6H3), 4.02 (m, 4 H, CHMe2), 3.20 (m, 2 H, Cy), 1.57 (s, 3 H, Mo±Me),
1.54 (s, 3 H, NC(Me)N), 1.10±2.10 (m, 20 H, Cy), 1.27 (d, 12 H, CHMe2),
1.17 (d, 12 H, CHMe2).
MS (98Mo): m/z (%) = 704(10) [M+]; 529(55) [M+±ArN]; 83(100) [Cy].
MS (98Mo): m/z (%) = 684(100) [M+].
[(2,6-i-Pr2C6H3N)2MoCl{N(Cy)C(N(i-Pr)2)N(Cy)}] (3). The
synthetic procedure is similar to that described for
[(2,6-i-Pr2C6H3N)2MoMe{N(Cy)C(N(i-Pr)2N(Cy)}] (7). The
synthetic procedure is similar to that of 6. MeLi (0.63 mL,
1.0 mmol, 1.6 M in solution in ether) was added dropwise to
a solution of 3 (0.79 g, 1.0 mmol) in THF (20 mL) at ±57 °C.
Yield: 0.54 g (70%). M. p. 190±195 °C.
2.
[N(C6H11)C(N(i-Pr)2)N(C6H11)]Li ´ O(C2H5)2
(5.9 g,
15.5 mmol) was added in several portions to a solution of 1
(9.1 g, 15 mmol) in THF (100 mL) at ±78 °C. Yield: 4.5 g
(37%). M. p. 218±220 °C.
C44H73MoN5 (768.01 g/mol)
C43H70ClMoN5 (788.45 g/mol)
Analyses: C 68.45 (calc 68.75); H 9.60 (9.58); N 8.96
(9.12)%.
Analyses:
C 65.45
(calc
65.50);
H 8.88
(8.95);
N 8.78(7.88)%.
1H NMR (200 MHz, C6H6 solution): d (ppm) = 6.85±7.10 (m, 6 H, 2,6-i-
Pr2C6H3), 4.08 (m, 4 H, CHMe2), 3,65 (m, 2 H, Cy), 3.55 (m, 2 H,
NC(N(CHMe2)2)N), 1.60 (s, 3 H, Mo±Me), 1.10±2.10 (m, 20 H, Cy), 1.31
(d, 12 H, CHMe2), 1.24 (d, 12 H, CHMe2), 1.11 (d, 12 H,
NC(N(CHMe2)2)N).
1H NMR (200 MHz, C6D6 solution): d (ppm) = 6.90±7.10 (m, 6 H, i-
Pr2C6H3), 4.19 (m, 4 H, CHMe2), 3.65 (m, 2 H, Cy), 3.55 (m, 2 H,
NC(N(CHMe2))N), 1.31 (d, 12 H, CHMe2), 1.23 (d, 12 H, CHMe2),
1.20 ppm (d, 12 H, NC(N(CHMe2))N), 1.10±2.70 (m, 20 H, Cy).
MS (98Mo): m/z (%) = 789(100) [M+]; 614(68) [M+±ArN].
MS (98Mo): m/z (%) = 769(100) [M+].
[(2,6-i-Pr2C6H3N)2MoCl{N(Cy)C(N(SiMe3)2)N(Cy)}] (4). A
solution of [N(C6H11)C(N(SiMe3)2)N(C6H11)]Li ´ O(C2H5)2
(0.75 g, 2.0 mmol) in THF (20 mL) was added dropwise to 1
(1.20 g, 2.0 mmol) in THF (20 mL) at ±70 °C over a period
of 10 min. After warming slowly to ambient temperature,
the resulting solution was stirred at 22 °C for 16 h. After re-
moval of all the volatiles, the residue was extracted with n-
pentane (20 mL). Removing of n-pentane from the extract
afforded 4 as brown-yellow powder. Yield: 1.2 g (70%). M. p.
82±84 °C.
[(2,6-i-Pr2C6H3N)2MoCl2]([NH=C(C6H5)CH(SiMe3)2] (8).
A
solution of [N(SiMe3)C(C6H5)C(SiMe3)2]Li ´ THF
(0.205 g, 0.49 mmol) in ether (15 mL) was added dropwise to
a solution of 1 (0.30 g, 0.49 mmol) in ether (100 mL) at
±78 °C. After warming slowly to ambient temperature, the
reaction mixture was stirred for 16 h at 22 °C. After remov-
ing all the volatiles, the residue was extracted with n-pentane
(15 mL). The extract was cooled at ±5 °C for 18 h to afford
yellow crystals. Yield: 0.034 g (9%). M. p. 147±150 °C.
C38H59Cl2MoN3Si2 (780.90 g/mol)
C43H74ClMoN5Si2 (848.65 g/mol)
Analyses: C 58.37 (58.45); H 7.63 (7.62); N 5.57 (5.38)%.
Analyses: C 60.61 (calc 60.85); H 9.08 (8.78); N 8.92
(8.35)%.
1H NMR (200 MHz, C6D6 solution): d (ppm) = 6.85±7.10 (m, 6 H, i-
Pr2C6H3), 4.08 (m, 4 H, CHMe2), 3.73 (m, 2 H, Cy), 1.10±2.10 (m, 20 H,
Cy), 1.28 (d, 12 H, CHMe2), 1.27 (d, 12 H, CHMe2), 0.27 (d, 18 H, SiMe3).
MS (98Mo): m/z = 849 [M+]; 674 [M+±ArN].
29Si NMR: d (ppm) = 7.47.
MS
(
98Mo): m/z (%) = 745(18) [M+±Cl]; 570(18) [M+±Cl±ArN];
175(100) [ArN].
Single crystal X-ray structral determination and
refinement
[(2,6-i-Pr2C6H3N)2MoCl{C6H5C(NSiMe3)2}] (5). The syn-
thetic procedure is similar to that of 4. [C6H5C(NSi-
Me3)2]Li ´ THF (1.26 g, 3.68 mmol) was dissolved in THF
A summary of the crystal data, data collection, solution and
refinement parameters for 7 and 8 is given in table 3. The
Z. Anorg. Allg. Chem. 2000, 626, 1660±1664
1663
Hao, Haijun
