3474 Inorganic Chemistry, Vol. 40, No. 14, 2001
Liaw et al.
(t), 6.94 (d) ppm (Te-C6H4). Absorption spectrum (THF) [λmax, nm
(e, M-1 cm-1)]: 409(3536), 514(2329). Anal. Calcd for C45H35O3N2-
TeP2Mn: C, 60.31; H, 3.94; N, 3.13. Found: C, 59.89; H, 3.93; N,
HO-(CH2)2-SH) generates B (Scheme 5b). Conversion of
intermediate B to C was not observed, presumably due to the
better chelating ability of [TeC6H4-o-NH2]- than that of
[S‚‚‚E′H]- (Scheme 5c). As expected, a similar oxidation/
deprotonation of thiolate/amine was observed when the complex
B was treated with dry O2 resulting in regeneration of complex
1 (Scheme 5b′,d). Complex D is formed on reacting complex 1
with the “favorable bidentate ligands” HE‚‚‚E′H (e.g., [HSC6H4-
o-SH], [HSC6H4-o-NH2], [HSC6H4-o-OH], [HOC6H4-o-OH])
(Scheme 5e-g). Specifically, the more stable intermediate
(intermediate C) formation, not the π-donating ability of
bidentate ligands [EC6H4-o-E′]2- (E ) Te, Se, S, O; E′ ) NH,
S, O), is the major factor governing the reaction product
(reaction route) in the π-donating ligand metathesis reaction
(Scheme 5).
1
3.26. Comlex 2. IR ν(CO): 1971 s, 1869 s cm-1 (THF). H NMR
(C4D8O): δ 9.32 (br) (N-H), 7.69 (d), 7.05 (d), 6.81 (t), 6.55 (t) ppm
(Se-C6H4). Absorption spectrum (THF) [λmax, nm (e, M-1 cm-1)]: 400-
(2794), 505(1182). Anal. Calcd for C45H35O3N2SeP2Mn: C, 63.76; H,
4.16; N, 3.31. Found: C, 63.67; H, 4.19; N, 3.30.
Reaction of [PPN][Mn(CO)5] and 2,3-Quinoxalinedithiol. [PPN]-
[Mn(CO)5] (0.2 mmol, 0.147 g) and 2,3-quinoxalinedithiol (0.2 mmol,
0.039 g) were dissolved in 3 mL of THF and stirred under nitrogen for
2 days at ambient temperature. Hexane was then added slowly to
precipitate a dark green semisolid [PPN][Mn(CO)4(-SC8N2H4-o-S-
)] (5). IR ν(CO) (THF): 2065 w, 1990 s, 1964 m, 1921 m cm-1. The
complex 5 solution was purged with N2 (30 min) and monitored with
FTIR. IR spectrum, ν(CO) (THF) 1997 s, 1902 s,br cm-1, having the
same pattern as, but differing slightly in position from, that of [Mn-
(CO)3(-SC6H4-o-S-)]- (IR ν(CO) (THF): 1986 s, 1887 br cm-1),7
indicated the formation of [PPN][Mn(CO)3(-SC8N2H4-o-S-)] (6).
Complex 6 was converted completely to complex 5 on stirring under
CO atmosphere for 10 min at room temperature. Attempts to isolate
pure complex 5 led to isolation of the mixture of complexes 5 and 6.
After stirring a THF solution of complex 6 for 3 h at 25 °C, hexane
was then added to precipitate the dark brown solid [PPN]2[(CO)3Mn-
(µ-SC8N2H4-o-S)]2 (7). Solvent was removed and dried under vacuum.
Then the dark brown complex 7 was recrystallized with CH2Cl2-diethyl
ether (0.086 g, 48%). Diffusion of diethyl ether into CH2Cl2 solution
of complex 7 at -15 °C for 2 weeks led to dark brown crystals suitable
for X-ray crystallography. IR ν(CO): 2005 s, 1914 br cm-1 (CH2Cl2).
1H NMR (CD2Cl2): δ 7.63 (d) (SC8N2H4-o-S), 7.49-7.45 (m) ppm
(Ph). Absorption spectrum (CH2Cl2) [λmax, nm (e, M-1 cm-1)]: 404-
(36456), 521(6892), 577(4608). Anal. Calcd for C94H68O6N6S4P4Mn2:
C, 64.90; H, 3.94; N, 4.83. Found: C, 64.80; H, 4.23; N, 4.76.
Reaction of Complex 1 with 1,2-Benzenedithiol (hydroxythiophe-
nol and catechol, respectively). To a stirred solution of compound 1
(0.090 g, 0.1 mmol) in THF (3 mL) 1,2-benzenedithiol (15 µL, 0.1
mmol) [hydroxythiophenol (10.6 µL, 0.1 mmol) and catechol (0.011
g, 0.1 mmol), respectively] were added under N2 at room temperature.
The reaction solution was stirred for 5 min and monitored by IR. The
IR spectrum, ν(CO) 1986 s, 1887 br cm-1 (THF), was assigned to the
formation of the known [Mn(CO)3(-SC6H4-o-S-)]- (14) (IR ν(CO)
spectrum 1990 s, 1890 s, 1881 s cm-1 (THF) assigned to [Mn(CO)3-
(-SC6H4-o-O-)]- (15); IR ν(CO) spectrum 1996 s, 1887 br cm-1
(THF) assigned to [Mn(CO)3(-OC6H4-o-O-)]- (16)).2,7 Complexes 15
and 16 are extremely unstable. Stirring of the THF solution of complex
15 (16) overnight at room temperature led to insoluble decomposition
solid. Attempts to isolate complexes 15 and 16 were unsuccessful.
Preparation of [(Mn(CO)3)2(µ-SC6H4-o-S-S-C6H4-o-µ-S-)] (17).
A portion (35 µL, 0.2 mmol) of HBF4 (or [Cp2Fe][PF6], 0.066 g, 0.2
mmol) was added dropwise by syringe into a CH2Cl2 (3 mL) solution
of [PPN][Mn(CO)3(-SC6H4-o-S-)] (0.163 g, 0.2 mmol) under N2 at
ambient temperature. A vigorous reaction occurred immediately. The
color of the reaction mixture turned from dark red purple to red brown.
The reaction was monitored with FTIR (the evolution of H2 gas was
identified by GC). Hexane (10 mL) was added to precipitate the
insoluble solid [PPN][BF4]. The resulting mixture was filtered to remove
[PPN][BF4] and solvent was removed from the filtrate under vacuum.
Five milliliters of hexane was added to redissolve the product.
Recrystallization from slow evaporation from the concentrated hexane
solution (2 mL) gave brown crystals (0.038 g, 68%) at -15 °C, and
the crystals were used in the X-ray diffraction study. IR ν(CO): 2041
w, 2022 vs, 1966 m, 1944 m cm-1 (CH2Cl2); 2043 w, 2025 vs, 1974
Also, the reactions of complex 1 with electrophiles occurring
at the more electron-rich amide site support that the more
electron-rich amide donor of the chelating 2-tellurolatophenyl-
amido occupies an equatorial site as indicated by a shorter
MnI-N bond length of the trigonal bipyramidal complex 1.3,6,7
Experimental Section
Manipulations, reactions, and transfers of samples were conducted
under nitrogen according to standard Schlenk techniques or in a
glovebox (argon gas). Solvents were distilled under nitrogen from
appropriate drying agents (diethyl ether from CaH2; acetonitrile from
CaH2-P2O5; methylene chloride from P2O5; hexane and tetrahydrofuran
(THF) from sodium-benzophenone) and stored in dried, N2-filled flasks
over 4 Å molecular sieves. Nitrogen was purged through these solvents
before use. Solvent was transferred to reaction vessels via stainless
steel cannula under positive pressure of N2. The reagents dimanganese
decacarbonyl, 2-aminophenyl disulfide, 2-aminophenyl diselenide, 1,2-
benzenedithiol, 2-aminophenylthiol, hydroxythiophenol, catechol, 1,3-
propanedithiol, ferrocenium hexafluorophosphate, bis(triphenylphos-
phoranylidene)ammonium chloride, fluoroboric acid, and 2,3-qui-
noxalinedithiol (Lancaster/Aldrich) were used as received. Compound
2-aminophenyl ditelluride was synthesized by published procedures.9
Infrared spectra of the carbonyl ν(CO) frequency were recorded on a
Bio-Rad Model FTS-185 spectrophotometer with sealed solution cells
1
(0.1 mm) and KBr windows. H and 13C NMR spectra were obtained
on a Bruker Model AC 200 spectrometer. UV-vis spectra were
recorded on a GBC 918 spectrophotometer. Analyses of carbon,
hydrogen, and nitrogen were obtained with a CHN analyzer (Heraeus).
Preparation of [PPN][Mn(CO)3(-EC6H4-o-NH-)] (E ) Te (1),
Se (2)). The compounds [PPN][Mn(CO)5] (0.5 mmol, 0.367 g)21 and
2-aminophenyl ditelluride (0.5 mmol, 0.220 g) (or 2-aminophenyl
diselenide) were dissolved in 4 mL of THF and stirred at ambient
temperature. A vigorous reaction occurred with evolution of CO gas.
The reaction was monitored with FTIR. IR spectra, 2027 m, 1956 vs,
1946 sh, 1911 m cm-1 (ν CO) (THF) were assigned to the formation of
cis-[PPN][Mn(CO)4(-TeC6H4-o-NH2)2] (3). A gentle stream of dry O2
(about 7 mL) was bubbled through the brown solution. The brown
solution completely converted into a dark brown solution accompanied
by formation of byproducts, 2-aminophenyl ditelluride and H2O
(identified by 1H NMR in the separate NMR experiment). The solution
was then filtered through Celite, and hexane (10 mL) was added to
precipitate the dark brown solid [PPN][Mn(CO)3(-TeC6H4-o-NH-)]
(1) (dark brown semisolid [PPN][Mn(CO)3(-SeC6H4-o-NH-)] (2)).
The solid was washed with hexane (5 mL) and recrystallized from
THF-hexane (1:5 ratio). The yield of dark brown product 1 was 0.388
g (86%) (72% for complex 2). Diffusion of hexane into a solution of
complex 1 in THF at - 15 °C for 4 weeks led to dark brown crystals
suitable for X-ray crystallogaphy. Complex 1. IR ν(CO): 1966 s, 1867
1
m, 1960 sh, 1952 s cm-1 (hexane). H NMR (C4D8O): δ 7.46 (m),
7.70 (d), 8.20 (d) ppm (C6H4). 13C NMR (C4D8O): δ 128.3, 132.8,
133.4 ppm (C6H4). Absorption spectrum (THF) [λmax, nm (e, M-1
cm-1)]: 390(3325), 485(1989). Anal. Calcd for C15H8O3S4Mn2: C,
38.69; H, 1.43. Found: C, 38.40; H, 1.53.
1
s cm-1 (THF). H NMR (C4D8O): δ 9.66 (br) (N-H), 6.40 (t), 6.77
Reaction of Complex 17 with [PPN][BH4]. A solution containing
0.056 g (0.1 mmol) of complex 17 and 0.112 g (0.2 mmol) of [PPN]-
[BH4] in THF (3 mL) was stirred at ambient temperature for 5 h and
(21) (a) Inkrott, K.; Goetze, G.; Shore, S. G. J. Organomet. Chem. 1978,
154, 337. (b) Faltynek, R. A.; Wrighton M. S. J. Am. Chem. Soc.
1978, 100, 2701.
monitored by FTIR. The IR spectrum (ν(CO): 1986 s, 1887 br cm-1
)
Liaw
