Sila-drugs, XXIV. Sila-analogues of nifedipine-like dialkyl 4-aryl-2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxylates, II

Full text of DOI:10.1515/znb-1982-0410

The Preparation of Some Monodentate Coordinated Semicarbazone(O)
and Thiosemicarbazone(S) Cationic But-2-yne Tungsten(II) Complexes
Paul K. Baker* and Kevin R. Flower
Department of Chemistry, University of Wales, Bangor, Gwynedd LL57 2UW (U. K.)
Z. Naturforsch. 48b, 1715-1718 (1993); received July 13,1993
Monodentate, Semicarbazone, Thiosemicarbazone, But-2-yne, Tungsten(II)
Reaction of [W I(CO)(NCMe)(dppm)(7 7 2 -MeC
with an equimolar quantity of L {L = RR'CNNHCONH
L {L = RR'CNNHCSNH (R = R ' = Me, Et; R = Me, R ' = Et, Pr", Bu', Ph; R = H, R ' = Ph)}
gives the monodentately coordinated semicarbazone or thiosemicarbazone products
[WI(CO)L(dppm)(?7 2 -MeC Me)][BF4] (1-9). 13C NMR spectroscopy suggests that the
but- -yne ligand is donating four electrons to the tungsten in
[WI(CO){H(Ph)CNNHCSNH }(dppm)(?7 2 -MeC Me)][BF4].
2
Me)][BF4] {dppm
=
Ph
2
P(CH )PPh2}
2
2
(R = R ' = Me; R = H, R' = Ph)} or
2
2
2
2
2
Introduction
[WI2(CO)(dppm)(?
alent of Ag[BF4] in acetonitrile [9]. Equimolar
quantities of [WI(CO)(NCMe)(dppm)(? 2-
MeC2Me)][BF4] and L {L = R R 'CNNHCONH2
(R = R' = Me; R = H, R' = Ph) or RR'CNNHCSNH,
(R = R ' = Me, Et; R = Me, R' = Et, Pr«, Ph; R = H~
7
2-MeC2Me)] with one equiv-
Transition-metal ions with semicarbazones and
thiosemicarbazones have been extensively studied
[1-3], and generally contain the semicarbazone or
thiosemicarbazone ligands attached as bidentate li-
gands through the oxygen or sulphur and the hy-
drazine nitrogen atom. Hitherto, very few low-
valent organotransition-metal complexes with se-
micarbazones and thiosemicarbazones have been
described [4- 8]. For example, the organo-iron com-
plexes [Fe(CO)2LCp][PF6] previously reported [7]
(L = H2NNHCSNH2 or R'R"CNNHCSNH2 (R' =
R" = Me; R' = H, R" = Ph; R' = H, R" = p-N 0 2Ph;
R' = Me, R" = p-MePh; R'R" = C5H 10)} also contain
monodentately coordinated thiosemicarbazide and
thiosemicarbazone ligands, which was confirmed by
the X-ray crystal structure determination for R' =
H, R" = Ph [7].
In this paper we report the synthesis and
spectroscopic properties of some new mono-
dentately coordinated semicarbazone(O) and thio-
semicarbazone(S) tungsten(II)-but-2-yne comple-
xes, [WI(CO)L(dppm)(7/2-MeC2Me)][BF4] {L =
RR'CNNHCONH2(R = R' = Me; R = H, R' = Ph)
or RR'CNNHCSNH2 (R = R' = Me, Et; R = Me,
R' = Et, Pr", Bu', Ph; R = H, R' = Ph)}.
7
R '
= Ph)} in CH2C12 {or acetone for L =
Me(Bu')CNNHCSNH2} at room temperature
afford the new monodentately attached semi-
carbazone
or
thiosemicarbazone
products
[WI(CO)L(dppm)(?
7
2-MeC2Me)][BF4] (1 -9 ) in
good yield. All the new complexes 1 -9 have been
fully characterized by elemental analysis (C, H and
N) (Table I), infrared (Table II), >H and for
[WI(CO){H(Ph)CNNHCSNH2}(dppm)-
(? 2-MeC2Me)][BF4] (9) by 13C NMR spectroscopy
7
(Tables III and IV). All the new complexes 1 -9 are
air-sensitive in solution, however, they can be stor-
ed under nitrogen in the solid state. The complexes
are all reasonably soluble in chlorinated solvents
such as CHC13and CH2C12but more soluble in ace-
tone, and as expected since they are ionic they are
insoluble in hydrocarbon solvents and diethyl ether.
The infrared spectra of complexes 1 - 9 all show
a single carbonyl band at = 1930 cm-1, which as
expected is in a similar position to the complexes
we
[WI(CO)L(dppm)(772-MeC2Me)][BF4]
SC(NH2)2, SC(NMe2)2, SC(NH2)(NHPhMe-o),
SC(NHPh)2, SC(NH2)Me, ÖC(NH2)2 or
have
previously
described,
namely
{L
Results and Discussion
The starting material
[WI(CO)(NCMe)(dppm)(? 2-MeC2Me)][BF4] was
prepared by reacting the neutral diiodo complex
7
OC(NH2)Me} [10]. The thiourea complex
[WI(C0){SC(NH2)2}(dppm)(?72-MeC2Me)][C104]
which was crystallized as its perchlorate salt was
crystallographically characterized. Since the colours
and spectroscopic properties of 1 -9 are similar to
[WI(C0){SC(NH2)2}(dppm)(?72-MeC2Me)][C104],
* Reprint requests to Dr. P. K. Baker.
Verlag der Zeitschrift für Naturforschung,
D-72072 Tübingen
0932-0776/93/1200-1715/$ 01.00/0
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1716
P. K. Baker-K. R. Flower • Semicarbazone(O) and Thiosemicarbazone Tungsten(II) Complexes
Table I. Physical and analytical data3for [WI(CO)(RR'CNNHCONH-, or
RR'CNNHCSNH2)(dppm)(? 2-MeC2Me)][BF4].
7
Com-
pound
No.
Colour
Yield Analytical data
(Found (%) Calcd)
C
H
N
1
2
3
4
5
6
7
8
9
[WI(CO)(Me2CNNHCONH2)(dppm)(?
[WI(CO){H(Ph)CNNHCONH2}(dppm)(?
[WI(CO)(Me2CNNHCSNH2)(dppm)(? 2-MeC2Me)][BF4]
[WI(CO)(Et2CNNHCSNH2)(dppm)(/ 2-MeC2Me)][BF4]
[WI(CO){Me(Et)CNNHCSNH2}(dppm)(? 2-MeC2Me)][BF4]
[WI(CO){Me(Pr',)CNNHCSNH2}(dppm)(?;2-MeC2Me)][BF4]
[WI(CO){Me(Bu')CNNHCSNH2}(dppm)(/ 2-MeC2Me)][BF4]
[WI(CO){Me(Ph)CNNHCSNH2}(dppm)(? 2-MeC2Me)][BF4]
[WI(CO){H(Ph)CNNHCSNH2}(dppm)(? 2-MeC2Me)][BF4]
7
2-MeC2Me)][BF4]
Brown 59
Brown 59
41.4
3.9
3.9
(41.7)
44.2
(3.8)
3.7
(4.3)
3.7
7
2-MeC2Me)][BF4]
(44.4)
40.7
(3.6)
4.0
(4.1)
3.9
7
Pink
Pink
Pink
Pink
Pink
Pink
Pink
66
62
62
67
63
65
67
(41.0)
42.1
(3.7)
4.2
(4.2)
3.7
7
(42.2)
41.6
(4.0)
3.7
(4.1)
3.8
7
(41.7)
42.4
(3.9)
4.1
(4.2)
3.8
(42.3)
42.8
(4.1)
3.7
(4.0)
4.4
7
(42.8) (4.2)
(4.1)
3.9
7
44.2
(44.3)
43.5
3.7
(3.8)
3.6
(4.0)
3.7
7
(43.7)
(3.6)
(4.0)
Calculated values in parantheses.
Table II. Infrared data3for
the proposed structure of 1- 9 is shown in Fig. 1with
either the oxygen or the sulphur atoms of the semi-
carbazone or thiosemicarbazone ligands attached to
the tungsten. This is the same type of structure as
the monodentately coordinated thiosemicarbazone
iron complex [Fe(CO)2(PhCHNNHCSNH2)Cp][PF6]
[7], i. e. with an (S) bonded thiosemicarbazone.
[WI(CO)(RR'CNNHCONH2or
RR'CNNHCSNH2)(dppm)(? 2-MeC2Me)][BF4].
7
Com- Infrared group frequencies (cm4)
pound v(NH) v(C = 0) v(C =0) v(C =S) v(BF)
No.
1
2
3325 s 1935 s
3150 m
1655 s
1658 s
-
-
1020 bs
1020 bs
The
NMR spectra for 1 and 3 -9 all show the
3450 m 1935 s
3350 m
expected features for the structure shown in Fig.l.
The but-2-yne ligands show two single resonances
which is in accord with the two methyl groups being
in different environments as shown in Fig. 1. Where-
as complex 2,
3300 m
3
3420 m 1925 s
3320 m
-
-
1575 w 1020 bs
1570 w 1020 bs
3220 m
4
3460 m 1935 s
3430 m
3330 m
3225 m
Me
5
6
3325 bm 1930 s
3175 m
-
-
1575 w 1020 bs
1570 w 1020 bs
3425 m 1935 s
3325 m
Ph,p
3225 m
/ X
H,C
7
8
3410 m 1920 s
3320 m
-
-
1575 w 1020 bs
1575 w 1020 bs
\
Ph_P / "
\
3460 m 1920 s
3425 m
C'
3315 m
3220 m
9
3425 m 1935 s
3320 m
-
1580 w 1020 bs
H
^N = C ^
R*
3250 m
Fig. 1. Proposed structure for
[WI(CO)(RR'CNNHCENH2)(dppm)(?
(1-9) (E = O or S).
7
2-MeC2Me)][BF4]
3
Spectra recorded as thin films in CHC13between
NaCl plates, s = strong, m = medium, b = broad.
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1717
P. K. Baker-K . R. Flower • Semicarbazone(O) and Thiosemicarbazone Tungsten(II) Complexes
Table III. *H NMR data for [W I(CO)(RR'CNNHCONH or RR'CNNHCSNH )(dppm)(^ -MeC
Compound No. *H NMR chemical shifts (<3in ppm)a
3
2
2
2
2
Me)][BF4],
1
2
3
4
5
6
9.97 (s, 1H, NH); 8.01-6.9 (bm, 20H, P h -H , 2H , NH2); 4.63 (bm, 2H , PCH
= CMe); 2.92 (s, 3H, =CM e); 2.18 (s, H, CH3)
10.0 (s, 1H, NH); 9.02 (s, 1H, N = CH); 8.0-6.95 (bm, 25H, P h -H , 2H , NH2); 4.73 (bm, 2H,
PCH,P); 2.92 (s, H, = CMe)
9.98 (s, 1H, NH); 8.1-6.95 (bm, 20H, P h -H , 2H , NH2); 4.95 (bm, 2H , PCH
H, CH3)
2
P); 3.12 (s, 3H,
6
6
2
P); 3.15 (s, 3H,
= CMe): 3.10 (s, 3 H, = CMe): 2.15 (s,
6
10.08 (s, 1H, NH); 8.08-6.92 (bm, 20H, P h -H , 2H , NH2); 4.86 (bm, 2H , PCH
= CMe): 3.09 (s, 3H, = CMe): 2.42 (m, 4H , CH2); 1.15 (m ^ H , CH3)
2
P); 3.16 (s, 3H,
10.23 (s, 1H, NH); 8.4-6.9 (bm, 20H, P h -H , 2H , NH2); 3.15 (s, 3H, =CM e): 2.95 (s, 3H,
= CMe): 2.49 (m, 2H, CH2); 2.05 (s, 3H, CH3); 1.15 (t, 3H, CH3, / Hh = 7.3 Hz)
9.98 (s, 1H, NH), 8.21-6.95 (bm, 20H, P h -H , 2H , NH2); 4.73 (bm, 2H , PCH P); 3.10 (s, 3H,
2
= CMe): 2.92 (s, 3H, = CMe): 2.42 (t, 2H , CH2, JHH= 6.25 Hz); 2.14 (s, 3H, CH3); 1.65 (m, 2H,
CH2); 0.95 (t, 3 H, CH ,7HH= 6.25 Hz)
3
7
8
9.96 (s, 1H, NH); 8.15-6.90 (bm, 20H, P h -H , 2H , NH2); 4.76 (bm, 2H , PCH
= CMe): 2.95 (s, 3H, = CMe): 2.2 (s, 9 H, CH3); 2.10 (s, 3 H, CH3)
10.43 (s, 1H, NH); 8.15-7.0 (bm, 25H, P h -H , 2H , NH2); 4.80 (bm, 2H, PCH
= CMe); 3.04 (s, 3H, = CMe): 2.25 (s, 3H, CH3)
2
P); 3.12 (s, 3H,
2
P); 3.16 (s, 3H,
9
10.78 (s, 1H, NH); 9.95 (s, 1H, N = CH); 8.47 - 6.93 (bm, 25 H, Ph - H, 2 H, NH2); 4.72 (bm, 2 H,
PCH P); 3.13 (s, 3H, = CMe): 2.98 (s, 3H, =CM e)
2
a Spectra recorded in CDC1
3
(+ 25 °C) referenced to SiMe4. s = singlet, d = doublet, t = triplet, m = multiplet,
b = broad.
this complex. This also enables complexes 1 -9 to
obey the effective atomic number rule.
Table IV. 13C NMR data for
[WI(CO){H(Ph)CNNHCSNH
[BF4] (9).
3
2
}(dppm)(»/
2
-MeC Me)]-
2
It may be that the semicarbazone and thiosemi-
carbazone ligands in 1 -9 are not monodentately
coordinated but in a bidentate manner as in
[W(CO)(dppm)(CTN or S~N)(772-MeC2Me)][BF4]I
with the iodide displaced by the imine nitrogen
atom. This is very unlikely since the reactions of
[WI(CO) (Me2CNNHCONH2)(dppm)-
Compound
No.
13C NMR chemical shifts (d in ppm
) 3
228.9 (bd, C = C); 209.5 (s, C ^ O ); 178.9
(s, C = S); 162.5 (s, N = C); 138.6-127.8
(m, P h-C ); 29.84 (t, PCH P, JP^ =
9
2
13.2 Hz); 19.43 (s, =CM e); 17.26 (s,
= CMe)
(?72-MeC2Me)][BF4] (1) with two equivalents of
Na[BPh4] in acetonitrile did not give the bis(tetra-
phenylborate) exchanged product:
[W(CO)(dppm) (Me2CNNHCONH2)-
3
Spectrum recorded in CDC1 (+ 25 °C) referenced to
3
SiMe4. s = singlet, t - triplet, m = multiplet, bd = broad
doublet.
(?72-MeC2Me)][BPh4]2.
Experimental
[WI(CO){H(Ph)CNNHCONH2}(dppm)-
All manipulations were carried out under dry
nitrogen using standard Schlenk line techniques.
(772-MeC2Me)][BF4] shows a single resonance at
d - 2.92 ppm which suggests the but-2-yne is under-
going rapid propeller like rotation, fast on the NMR
timescale at room temperature. The 13C NMR spec-
trum for [WI(CO){H(Ph)CNNHCSNH2}(dppm)-
(?/2-MeC2Me)][BF4] (9) shows a broad resonance at
228.9 ppm for the alkyne contact carbons. From
Templeton and Ward’s [11] correlation of the num-
ber of electrons donated to the metal and the 13C
NMR alkyne contact carbon chemical shift, reso-
nances above 200 ppm suggest that the but-2-yne
ligand is donating four electrons to the tungsten in
The
complex
[WI(CO)(NCMe)(dppm)(? 2-
7
MeC2Me)][BF4] was prepared by the published me-
thod [9]. The semicarbazone and thiosemicarbazo-
ne ligands were prepared by the method of Sah and
Daniels [12]. All solvents and chemicals used were
of reagent grade quality, and the solvents were dried
and distilled before use.
Elemental analyses (C, H and N) were deter-
mined by using a Carlo Erba Elemental Analyser
MOD 1106 (using helium as the carrier gas). Infra-
red spectra were obtained as CHC13films between
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1718
P. K. Baker-K . R. Flower • Semiearbazone(O) and Thiosemicarbazone Tungsten(II) Complexes
NaCl plates and recorded on a Perkin-Elmer 1430
ratio recording IR spectrophotometer. ]H NMR
spectra were recorded on a Bruker AC 250 CP/MAS
NMR spectrometer and 13C NMR spectra were re-
corded on a Bruker WH 400 NMR spectrometer
with tetramethylsilane as a standard.
cationic complex [WI(CO)(Me2CNNHCSNH2)-
(dppm)(? 2-MeC2Me)][BF4] (3) which on recrystal-
lization from CH2Cl2/diethyl ether gave 0.36 g, 66%
of pure product.
Similar reactions of equimolar quantities of
7
[WI(CO)(NCMe)(dppm)(? 2-MeC2Me)][BF4] and
7
L {L = RR'CNNHCONH, (R = R' = Me; R = H,
R' = Ph) or RR'CNNHCSNH2 (R = R' = Et; R =
Me, R' = Et, Pr", Ph; R = H, R' = Ph} in CH2C12{or
acetone for Me(Bu')CNNHCSNH2} at room tem-
Preparation of
[WI(CO) (Me2CNNHCSNH2) (dppm)-
(rj2-MeC2M e)][BFJ (3)
perature gave [WI(CO)L(dppm)(? 2-MeC2Me)]-
7
[BF4] (1, 2, 4-9). For physical and analytical data
see Table I.
To [WI(CO)(NCMe)(dppm)(^2-MeC2Me)][BF4]
(0.5 g, 0.552 mmol) dissolved in CH2C12 (15 cm3)
with continuous stirring under a stream of dry
nitrogen was added Me2CNNHCSNH2 (0.0724 g,
0.552 mmol). After 3 h the solution was filtered and
the solvent volume reduced to 2 cm3in vacuo. Drop-
wise addition of diethyl ether precipitated the pink
K. R. F. thanks the SERC for a studentship, and
we also thank Dr. O. W. Howarth for obtaining the
13C NMR spectrum from the University of Warwick
on the SERC High Field NMR Service.
[7] M. J. M. Campbell, E. Morrison, V. Rogers, P. K.
Baker, D. C. Povey, G. W. Smith, Polyhedron 8,2371
(1989).
[1] M. J. M. Campbell, Coord. Chem. Rev. 15, 279
(1975) and references therein.
[2] S. Padhye, G. B. Kauffman, Coord. Chem. Rev. 63,
127 (1985), and references therein.
[8] P. K. Baker, S. G. Fraser, J. Coord. Chem. 20, 267
(1989).
[3] R. B. Singh, B. S. Garg, R. P. Singh, Talanta 25,619
(1978).
[9] P. K. Baker, K. R. Flower, M. G. B. Drew, G. For-
syth, J. Chem. Soc., Dalton Trans. 1989,1903.
[10] P. K. Baker, K. R. Flower, P. A. Bates, M. B. Hurst-
house, J. Organomet. Chem. 372, 263 (1989).
[11] J. L. Templeton, B. C. Ward, J. Am. Chem. Soc. 102,
3288 (1980).
[4] V. Srivastava, S. Sengupta, S. C. Tripathi, Synth.
React. Inorg. Met.-Org. Chem. 15,163 (1985).
[5] M. J. M. Campbell, E. Morrison, V. Rogers, P. K.
Baker, Transition-Met. Chem. 11, 381 (1986).
[6] M. J. M. Campbell, E. C. Morrison, V. Rogers, P. K.
Baker, Polyhedron 7 ,1719 (1988).
[12] P. P. T. Sah, T. C. Daniels, Recueil 69,1545 (1950).
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