C-S bond cleavage during reactions between N,N- diethylthiocarbamoyliminothianes and [MOCl4]- complexes (M = Re, Tc)

Article abstract of DOI:10.1002/zaac.201100359

[MOCl₄]^- complexes (M = Re, Tc) react with thianes derived from N-[(diethylamino)(thiocarbonyl)]benzamidoyl chloride and 2-mercaptophenol (HL¹) and 2-mercaptoaniline (HL²) under C-S bond cleavage and formation of oxorhenium(V) and oxotechnetium(V) complexes with the resulting decomposition products 2-mercaptophenol and N-[(dialkylamino)thiocarbonyl]-N′-2-mercaptophenyl)benzamidine (H ₂L^2a), respectively. The products, (NBu ₄)[ReO(S,O-C₆H₄)₂], [ReOCl(L ^2a)] and [TcO(L^2a)] were obtained in good yields and isolated in crystalline form. Single-crystal X-ray studies reveal square-pyramidal coordination environments with apical oxo ligands for all three product complexes under study. Copyright

Full text of DOI:10.1002/zaac.201100359

ARTICLE
DOI: 10.1002/zaac.201100359
C–S Bond Cleavage during Reactions between N,N-
Diethylthiocarbamoyliminothianes and [MOCl4]– Complexes (M = Re, Tc)
Dirk Hauenstein,[a] Adelheid Hagenbach,[a] and Ulrich Abram*[a]
In Memory of Professor Kurt Dehnicke
Keywords: Rhenium; Technetium; Tridentate benzamidines; Oxo complexes; Structure analysis
Abstract. [MOCl4]– complexes (M = Re, Tc) react with thianes derived ine (H2L2a), respectively. The products, (NBu4)[ReO(S,O-C6H4)2],
from N-[(diethylamino)(thiocarbonyl)]benzamidoyl chloride and 2- [ReOCl(L2a)] and [TcO(L2a)] were obtained in good yields and isolated
mercaptophenol (HL1) and 2-mercaptoaniline (HL2) under C–S bond
cleavage and formation of oxorhenium(V) and oxotechnetium(V) com-
in crystalline form. Single-crystal X-ray studies reveal square-pyrami-
dal coordination environments with apical oxo ligands for all three
plexes with the resulting decomposition products 2-mercaptophenol product complexes under study.
and N-[(dialkylamino)thiocarbonyl]-NЈ-2-mercaptophenyl)benzamid-
the new ligands, preferably derivatives of thiosemicarbazides,
reveal promising cytotoxic properties against human MCF-7
breast cancer cells.[9]
Introduction
Rhenium and technetium complexes with bi- and tridentate
[N-[(dialkylamino)(thiocarbonyl)]benzamidines (I) are exten-
sively studied and a number of oxo, nitrido and carbonyl
complexes with such chelators were structurally character-
ised.[1–11] The ligands can readily be prepared by reactions
of the corresponding benzimidoyl chlorides (II) with func-
tionalised primary amines.[12,13] They allow a variety of
modifications in the periphery of their chelating system,
which tune their properties and also give access to amino
acid derivatives and bioconjugation.[8] Some complexes of
Surprisingly less is known about the coordination behaviour
of related thianes (III), which can be synthesised by reactions
of II with thiols. Some basic reports about such ligands are
given in an early paper[14] and the thesis of Köhler,[15] and
some coordination chemistry together with the structures of bi-
and tetranuclear silver complexes were described.[16]
In this paper, we report about the synthesis of two new thi-
ane derivatives of II and their reactions with (NBu4)[MOCl4]
(M = Re, Tc) complexes, which resulted in unexpected C–S
bond cleavage, which can finally be used for the synthesis of
complexes with novel ligands such as (L2a)2–.
Results and Discussion
The proligands HL1 and HL2 can readily be prepared by
reactions of II with one equivalent of 2-mercaptophenol or 0.5
equivalents of 2-aminothiophenol, respectively. The com-
pounds are obtained as pale yellow solids in medium yields.
The products were fully characterised by elemental analyses,
IR and NMR spectroscopy.
* Prof. Dr. U. Abram
Fax: +49-30-838-2676
E-Mail: ulrich.abram@fu-berlin.de
[a] Institute of Chemistry and Biochemistry
Freie Universität Berlin
Fabeckstraße 34–36
14195 Berlin, Germany
Z. Anorg. Allg. Chem. 2011, 637, 1889–1894
© 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
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D. Hauenstein, A. Hagenbach, U. Abram
ARTICLE
Additionally, X-ray structure analysis was performed for a
single crystal of HL1. The molecular structure of the com-
pound is depicted in Figure 1. Selected bond lengths and
angles are summarised in Table 1. The structural determination
shows an almost located C–N double bond between the atoms
C4 and N3, whereas the bond between N3 and C2 of
1.399(3) Å can be assigned to a single bond. This situation is
in contrast to the bonding features in dialkylaminothiocarbon-
ylbenzamidines, where also in the pro-ligands an extended de-
localisation of π-electron density between all carbon and nitro-
gen atoms is found.[2–13] The solid-state structure of HL1
shows a distorted Z configuration concerning the sulfur atoms,
which is stabilised by hydrogen bonds between O30 and the
sulfur atoms.
Scheme 1.
bond lengths and angles are contained in Table 2. The two mer-
captophenolato ligands are arranged in cis coordination in the
basal plane of a square pyramid, the apex of which is formed
by the oxo ligand. The rhenium atom is situated by 0.712(1) Å
above the basal plane. Such an arrangement is common for five-
coordinate oxo-, nitrido and phenylimidorhenium(V) complexes
and is explained by the steric requirements of the multiply
bonded oxygen and nitrogen atoms, and has also been found in
corresponding complexes with maleonitrildithiolato, ethane-1,2-
dithiolato or toluene-3,4-dithiolato ligands.[19–21]
Figure 1. Ellipsoid representation[17] of the molecular structure of
HL1. Hydrogen atoms on carbon atoms are omitted for clarity. Thermal
ellipsoids represent 50% probability.
Figure 2. Ellipsoid representation[17] of the complex anion of
(NBu4)[ReO(S,O-C6H4)2]. Hydrogen atoms are omitted for clarity.
Thermal ellipsoids represent 50% probability.
Table 1. Selected bond lengths /Å and angles /° in HL1.
S1–C2
C2–N21
C4–S2
S1–C2–N3
N3–C4–S2
Hydrogen bonds
1.679(3) C2–N3
1.326(3) N3–C4
1.781(2) S2–C32
1.399(3)
1.272(3)
1.768(2)
123.4(2)
101.83(9)
Table 2. Selected bond lengths /Å and angles /° in (NBu4)[ReO(S,O-
C6H4)2].
118.3(2)
C2–N3–C4
Re–O10
Re–O2
Re–S2
O10–Re–O1
O10–Re–S1
O1–Re–O2
O1–Re–S2
1.676(3)
1.998(3)
1.781(2)
108.7(2)
109.5(2)
79.5(1)
Re–O1
Re–S1
1.977(3)
2.284(2)
121.9(2) C4–S2–C32
d(D–H)
0.82
d(A···H)
2.61
d(D···A)
3.359(3)
3.059(2)
D–H···A
151.7
120.0
O10–Re–O2
O10–Re–S2
O1–Re–S1
O2–Re–S1
S1–Re–S2
110.8(2)
109.2(1)
83.0(1)
139.4(1)
89.06(5)
O30–H30.S1
O30–H30.S2
0.82
2.57
141.9(1)
82.8(1)
HL1 reacts with equimolar amounts of (NBu4)[ReOCl4] to O2–Re–S2
give a greenish-brown solution, from which green crystals of
(NBu4)[ReO(S,O-C6H4)2] were isolated upon concentration.
The facile cleavage of the C4–S2 bond during the reaction
The formation of the mercaptophenolato chelate is unexpected of HL1 with [ReOCl4]– is unexpected and seems to be metal-
and can be understood as the result of a hydrolytic decomposi- induced, since even prolonged heating of HL1 in aqueous
tion of HL1 under the influence of the rhenium complex as is methanol gave no evidence for the formation of mercaptophe-
given in Scheme 1. The yield of the chelate is expectedly low nol and/or N,N-diethyl-NЈ-benzoylthiourea. Most probable, the
for the 1:1 reaction, but can be increased to about 80 per cent reaction begins with a tridentate coordination of the metal on
when two equivalents of HL1 are used. No complex formation the S,S,O-donor set of HL1, and the hydrolytic cleavage of the
could be observed with the released benzoylthiourea, which C–S bond is a consequence of the decrease of electron density
also is known to be a suitable chelating ligand for {ReO}3+ at the central carbon atom upon coordination, which makes it
and {TcO}3+ atoms.[18]
more sensitive against a nucleophilic attack. Despite the fact,
The rhenium atom in (NBu4)[ReO(S,O-C6H4)2] is five-coor- that we could not finally prove this assumption by experimen-
dinate and the Re=O stretch is found at 961 cm–1, which is in tal data (e.g. by NMR spectroscopic data of intermediates), the
the normal range for square-pyramidal oxo and nitrido com- observed type of bond cleavage can be used for the synthesis
plexes of rhenium(V) and technetium(V).[19,20] Figure 2 depicts of metal complexes with ligands, which are not easily access-
an ellipsoid representation of the complex anion, and selected ible by conventional synthetic procedures (cf. Scheme 2).
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Z. Anorg. Allg. Chem. 2011, 1889–1894

C–S Bond Cleavage in N,N-Diethylthiocarbamoyliminothianes and [MOCl4]–
Scheme 2.
Figure 3. Ellipsoid representation[17] of the molecular structure of
[TcOCl(L2a)]. Hydrogen atoms are omitted for clarity. Thermal ellip-
soids represent 50% probability.
Thus, a corresponding C–S bond cleavage in HL2 can be
applied for the synthesis of metal complexes with the ligand
{L2a}–, the direct synthesis of which causes problems due to
the parallel attack of benzimidoyl chlorides to the amine and complexes is addressed during the discussion of the structure
mercapto sites of 1,2-aminobenzenethiol. The reaction of HL2 of the [ReO(S,O-C6H4)2]– anion (vide supra).
with (NBu4)[ReOCl4], however, yields the oxorhenium(V)
The Re–O10 and Tc–O10 distances of 1.657(5) and
complex [ReOCl(L2a)] in good yields as red crystals. A similar 1.680(6) Å are within the expected range of rhenium or techne-
reaction with (NBu4)[TcOCl4] gives the analogous technetium tium–oxygen double bonds.[18] The six-membered chelate
complex.
rings are strongly distorted for both complexes, with main de-
Both compounds are readily soluble in organic solvents such viations of 0.458(4) Å ([TcOCl(L2a)]) and 0.454(4) Å
as dichloromethane or chloroform and stable on air in the solid ([ReOCl(L2a)]) from the mean least-square planes each for the
state as well as in solutions. Infrared bands at 949 (Tc com- nitrogen atoms N5. Nevertheless, a considerable delocalisation
plex) and 976 cm–1 (Re compound) confirm the presence of of π-electron density is observed. This is indicated by the
terminal oxo ligands. The ratios between the aliphatic and the C–S and C–N bond lengths inside the chelate rings, which are
1
aromatic protons in the H NMR spectra strongly suggest that all in the range between carbon–sulfur and carbon–nitrogen
the ligand HL2 is no more intact and a similar C–S bond cleav- single and double bonds. This bond length equalisation is even
age as shown in Scheme 1 for HL1, also occurs during the extended to the C2–N21 bonds, which are significantly shorter
reactions of HL2 with [MOCl4]– (M = Tc, Re) complexes. An than expected for single bonds.
alternative approach to [ReOCl(L2a)] is given with a reaction
The latter fact is also reflected in the NMR spectra of the
starting from [ReOCl3(PPh3)2]. The sparingly soluble starting chelates, where a rotational barrier around the C2–N21 bonds
material rapidly dissolves during the reaction with HL2 in is indicated by the splitting of the ethyl signals into two sets
boiling dichloromethane. From the resulting red solution, of resonances. This is in accordance with structurally related
[ReOCl(L2a)] precipitates upon cooling and concentration.
rhenium and technetium complexes with thiocarbamoylbenza-
Both the technetium and the rhenium complexes crystallise midinates such as with the oxygen-analogous ligand derived
in the monoclinic space group P21/c with each two crystallo- from 2-aminophenol.[6,23]
graphically independent [MOCl(L2a)] molecules in the asym-
The chloro ligand in [ReOCl(L2a)] is only weakly bonded
metric units. An ellipsoid representation of the molecular and can readily be replaced as is demonstrated by a metathesis
structure of the technetium complex is shown in Figure 3. The reaction with CN–. When the complex is treated with KCN in
structure of the rhenium compound is virtually identical and a mixture of methanol and CH2Cl2 at ambient temperature, a
therefore no extra Figure is given. Selected bond lengths and red powder of [ReO(CN)(L2a)] precipitates (Scheme 3). The
angles of both compounds are compared in Table 3. The product is readily soluble in dichloromethane or chloroform
atomic labelling scheme of Figure 3 is also applied for the rhe- and yields large red crystals after recrystallisation from these
nium complex.
solvents. The IR spectrum shows an absorption at 2208 cm–1,
The complexes are five-coordinate with the donor atoms of which can be assigned to the νCN stretch. The Re=O band
the tridentate ligand together with the chloro ligands forming appears at 984 cm–1.
the basal planes of distorted square pyramids. The domination
Figure 4 shows the molecular structure of [ReO(CN)(L2a)].
of this coordination polyhedron over a trigonal pyramid is indi- Selected bond lengths and angles are compared to the values
cated by τ values between 0.23 and 0.32 for the four indepen- of [ReOCl(L2a)] and [TcOCl(L2a)] in Table 3. It is obvious that
dent molecules of the [MOCl(L2a)] complexes, where values all main structural features of the chloro complexes also apply
of 0 and 1 would be expected for idealised C4v and D3h geome- for the cyano compound. The complex has a distorted square-
tries, respectively.[22] Expectedly, the metal atoms are placed pyramidal coordination sphere (τ = 0.25) with the oxo ligand
above the basal planes: the corresponding distances are at the apex of the pyramid. The six membered chelate ring
0.733(2) Å for the technetium complex and 0.700(2) Å for show similar deviations from planarity as discussed for the
[ReOCl(L2a)] (values given for one of the two independent chloro complexes (here with a maximum deviation for N5 of
species each). This common structural feature of monooxo 0.454(4) Å).
Z. Anorg. Allg. Chem. 2011, 1889–1894
© 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
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D. Hauenstein, A. Hagenbach, U. Abram
ARTICLE
Table 3. Selected bond lengths /Å and angles /° in [MOX(L2a)] com-
plexes (M = Re, Tc; X = Cl, CN). The atomic labelling scheme of
Figure 3 is also applied for [ReOCl(L2a)].
[TcOCl(L2a)]a) [ReOCl(L2a)]a)
[ReO(CN)(L2a)]
1.681(6)
M–O10
M–Cl/C40
M–S1
1.657(5)
1.640(5)
2.410(2)
2.398(2)
2.326(2)
2.318(2)
2.258(2)
2.267(2)
2.006(5)
2.016(5)
1.745(8)
1.742(7)
1.356(9)
1.356(8)
1.310(9)
1.307(8)
1.371(9)
1.374(8)
1.329(9)
1.321(9)
1.662(5)
1.680(6)
2.365(2)
2.374(2)
2.313(2)
2.312(2)
2.278(2)
2.272(2)
2.018(5)
2.010(6)
1.761(8)
1.756(9)
1.347(9)
1.34(1)
2.086(7)
2.313(2)
2.277(2)
2.025(5)
1.754(8)
1.34(1)
M–S2
M–N5
S1–C2
C2–N3
N3–C4
C4–N5
C2–N21
Figure 4. Ellipsoid representation[17] of the molecular structure of [Re-
O(CN)(L2a)]. Hydrogen atoms are omitted for clarity. Thermal ellip-
soids represent 50% probability.
1.30(1)
1.308(9)
1.376(8)
1.32(1)
1.287(9)
1.371(9)
1.387(9)
1.33(1)
Conclusions
N,N-Diethylthiocarbonylbenzimidoyl chloride readily reacts
with functionalised thiophenols such as 2-mercaptophenol or
2-mercaptoaniline with formation of the corresponding thianes.
The formed C–S bonds however do not resist reactions with
common technetium and rhenium complexes such as (NBu4)-
[MOCl4] or [ReOCl3(PPh3)2] and undergo a defined cleavage.
The resulting building blocks can be used as chelating ligands
as is demonstrated for 2-mercaptophenol and a tridentate
S,N,S-ligand, which is formed from HL2. For nuclear medical
labelling procedures or anticancer drugs with technetium and
rhenium atoms, the thianes, however, are most probably not
suitable due to their low stability.
1.33(1)
O10–M–Cl/C40 105.6(2)
104.6(2)
104.4(2)
111.8(2)
114.6(2)
111.4(2)
111.4(2)
104.9(3)
103.8(3)
82.71(7)
81.99(7)
83.70(7)
84.20(7)
150.3(2)
151.6(2)
136.62(7)
133.68(8)
89.9(2)
103.8(3)
114.1(2)
111.9(2)
107.7(2)
80.6(2)
106.0(2)
O10–M–S1
115.9(2)
112.8(2)
111.8(2)
111.5(2)
102.9(3)
104.3(2)
81.32(6)
82.72(6)
83.88(7)
82.97(7)
O10–M–S2
O10–M–N5
Cl/C40–M–S1
Cl/C40–M–S2
83.5(2)
Cl/C40–M–N5 151.3(2)
148.3(3)
133.61(8)
89.7(2)
149.4(2)
Experimental Section
S1–M–S2
S1–M–N5
S2–M–N5
M–S1–C2
S1–C2–N3
C2–N3–C4
N3–C4–N5
C4–N5–M
132.19(7)
135.59(7)
89.2(2)
89.3(2)
82.7(2)
Materials and Measurements
89.5(2)
82.1(2)
82.3(2)
All reagents used in this study were reagent grade and used without
further purification. Solvents were dried and used freshly distilled un-
less otherwise stated. (NBu4)[ReOCl4],[24] (NBu4)[TcOCl4],[25] and
[ReOCl3(PPh3)2][26] were prepared by standard procedures
81.7(2)
82.3(2)
105.1(2)
107.0(2)
122.0(5)
122.8(5)
122.7(6)
125.0(6)
123.2(6)
125.8(5)
115.9(4)
112.9(4)
106.8(3)
105.6(2)
123.1(6)
121.1(6)
124.8(7)
124.2(7)
127.1(7)
123.1(7)
113.1(4)
114.4(5)
106.8(3)
121.8(6)
125.7(6)
124.2(6)
114.4(4)
Infrared spectra were recorded from KBr pellets with a Shimadzu FT
instrument in the range 400–4000 cm–1. Elemental analyses were de-
termined using a Heraeus vario EL elemental analyser. The technetium
content was determined by liquid scintillation measurements. NMR
spectra were taken at 25 °C with a JEOL 400 MHz multinuclear spec-
trometer.
a) Values for two crystallographically independent molecules.
Radiation Precautions
99Tc is a weak β–-emitter. All manipulations with this isotope were
performed in a laboratory approved for the handling of radioactive
materials. Normal glassware provides adequate protection against the
low-energy β– emission of the technetium compounds. Secondary X-
rays (bremsstrahlung) play an important role only when larger amounts
of 99Tc are used.
Synthesis of HL1
2-Mercaptophenol (0.22 mL, 3 mmol) was dissolved in dry acetone
(20 mL) and triethylamine (0.35 mL, 2.5 mmol) was added. After ad-
Scheme 3.
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C–S Bond Cleavage in N,N-Diethylthiocarbamoyliminothianes and [MOCl4]–
dition of II (605 mg, 2.5 mmol), the mixture was stirred for 4 h at crystals deposited during this period. They were filtered off and
room temperature. During this period, colourless (NHEt3)Cl precipi-
washed with ethyl ether. Yield: 27 mg, 40%. The yield could be im-
tated, which was filtered off. The solvent was removed in vacuo and proved by using a 1:2 ratio between the rhenium precursor and HL1.
the residue was redissolved in dry THF and filtered off from a small
amount of an insoluble solid. Concentration of the solution and ad-
dition of ethyl ether gave a yellow solid. Yield: 430 mg, 50%. Elemen-
Elemental analysis. Calcd. for C28H44NO3ReS3: C, 48.53; H, 6.40; N,
2.02; S, 9.25%. Found: C, 48.27; H, 6.33; N, 2.49; S, 8.54%. IR:
3059 (w); 2962 (m); 2870 (m); 1570 (w); 1481 (m); 1450 (s);
tal analysis. Calcd. for C18H20N2OS2: C, 62.76; H, 5.85; N, 8.13; S, 1377 (w); 1219 (s); 1115 (w); 1022 (w); 961 (s); 841 (m); 756 (s);
1
18.61%. Found: C, 62.47; H, 5.29; N, 8.02; S, 18.42%. IR: 3267 (s);
3059 (w); 2974 (w); 2928 (w); 1609 (s); 1504 (s); 1312 (m); 1288 (s); 1.24 (m, 16 H, NCH2); 1.55 (m, 8 H, CH2); 6.70–7.55 ppm (m, 8 H,
687 (m); 656 (m) cm–1. H NMR (CDCl3): δ = 0.86 (m, 12 H, CH3);
1219 (s); 1146 (m); 1099 (m); 922 (m) 837 (m); 752 (s); 698 (m);
CHarom.).
1
582 (w) cm–1. H NMR (DMSO): δ = 1.18 (t, 3 H, CH3); 1.23 (t, 3
H, CH3); 3.60 (q, 2 H, CH2); 3.84 (q, 2 H, CH2); 6.66–7.48 (m, 9 H,
CHarom.); 10.14 ppm (s, 1 H, OH).
Synthesis of [TcOCl(L2a)]
(NBu4)[TcOCl4] (50 mg, 0.1 mmol) was dissolved in methanol (4 mL).
HL2 (54 mg, 0.1 mmol) was added and the resulting mixture was
stirred for 1 h at room temperature. A red precipitate deposited during
this time, which was collected and washed with a minimum amount
of cold methanol. The product was dissolved in CH2Cl2 (3 mL) and
overlayered with methanol (7 mL). Red crystals were formed during
the slow diffusion of methanol into the CH2Cl2 solution of the product.
Synthesis of HL2
2-Aminothiophenol (0.38 mL, 5 mmol) was dissolved in dry THF
(20 mL) and triethylamine (1.4 mL, 10 mmol) was added. After ad-
dition of II (2.4 g, 10 mmol), the mixture was stirred for 4 h at room
temperature. During this period, colourless (NHEt3)Cl precipitated,
which was filtered off. The solvent was removed in vacuo remaining
a yellow oil, which was suspended in ethyl ether (10 mL) and stored
at –20 °C for 18 h. The resulting yellow solid was carefully washed
with ethyl ether and dried in vacuo. Yield: 1.07 g, 40%. Elemental
analysis. Calcd. for C30H35N5S3: C, 64.13; H, 6.28; N, 12.47; S,
17.12%. Found: C, 63.87; H, 6.04; N, 12.21; S, 16.49%. IR:
2982 (m); 2932 (m); 1647 (s); 1508 (s); 1431 (m); 1354 (w); 1277 (m);
1215 (w); 1076 (w); 907 (w); 764 (m); 687 (m) cm–1. 1H NMR
(DMSO): δ = 1.12 (t, 3 H, CH3); 1.16 (t, 3 H, CH3); 1.25 (t, 3 H,
CH3); 1.30 (t, 3 H, CH3); 3.44 (m, 4 H, CH2); 3.93 (m, 4 H, CH2);
7.52–8.22 (m, 9 H, CHarom.); 10.06 ppm (s, 1 H, NH).
Yield:
39 mg
(80%).
Elemental
analysis.
Calcd.
for
C18H19ClN3OTcS2: Tc, 20.07%. Found: Tc, 18.79%. IR: 2974 (w);
1539 (s); 1458 (m); 1443 (m); 1335 (m) 1308 (m); 1223 (m); 949 (m);
1
748 (m) cm–1. H NMR (CDCl3): δ = 1.35 (dd, 6 H, CH3); 3.72 (m,
2 H, CH2); 4.03 (m, 1 H, CH2); 4.28 (m, 1 H, CH2); 6.68–7.54 ppm
(m, 9 H, CHarom.).
Synthesis of [ReOCl(L2a)]
a) (NBu4)[ReOCl4] (59 mg, 0.1 mmol) was dissolved in methanol
(2 mL). HL2 (54 mg, 0.1 mmol) was added and the resulting mixture
was stirred for 1 h at room temperature. A red precipitate deposited
during this time, which was collected and washed with a minimum
amount of cold methanol. The product was dissolved in CH2Cl2 (2 mL)
and overlayered with methanol (3 mL). Red crystals were formed dur-
ing the slow diffusion of methanol into the CH2Cl2 solution of the
Reaction between (NBu4)[ReOCl]4 and HL1, Synthesis of
(NBu4)[ReO(O,S-C6H4)2]
(NBu4)[ReOCl4] (59 mg, 0.1 mmol) was dissolved in methanol
(1.5 mL) and HL1 (33 mg, 0.1 mmol) was added. After stirring for 1 h,
CH2Cl2 (2 mL) was added and the mixture was kept for 24 h. Green product. Yield: 50 mg (86%).
Table 4. Crystal data and refinement results.
HL1
(NBu4)[ReO(S,O-C6H4)2]
[TcOCl(L2a)]
[ReOCl(L2a)]
[ReO(CN)(L2a)]
Formula
Mw
Crystal system
a /Å
b /Å
c /Å
C18H20N2OS2
344.48
orthorhombic
6.837(1)
15.256(1)
17.070(1)
90
90
90
1780.5(3)
P21cn
4
C28H44NO3S2Re
693.00
triclinic
C18H19ClN3OS2Tc
491.71
C18H19ClN3OS2Re
579.01
C19H19N4OS2Re2
569.70
monoclinic
19.265(1)
12.876(1)
17.070(1)
90
109.50(1)
90
3991.4(4)
P21/c
monoclinic
19.284(1)
12.870(1)
17.074(1)
90
109.33(1)
90
3998.6(4)
P21/c
monoclinic
11.132(1)
13.198(1)
13.619(1)
90
93.94(1)
90
1996.2(3)
P21/n
8.656(1)
9.532(1)
20.387(1)
78.81(1)
85.25(1)
64.42(1)
1488.4(3)
α /°
β /°
γ /°
V /Å3
¯
Space group
Z
P1
2
8
8
4
Dcalcd./g·cm–3
μ /mm–1
No. of reflections
No. of independent
No. parameters
R1/wR2
1.285
0.304
7213
4057
1.546
4.250
15548
7949
1.637
1.077
44414
10792
1.924
6.433
39681
10757
1.896
6.313
14503
5361
198
317
470
470
245
0.0494 / 0.1469
0.898
0.0395 / 0.0979
0.873
0.0671 / 0.1616
0.918
0.0542 / 0.1342
0.921
0.0560 / 0.1331
1.106
GOF
Flack parameter
CCDC deposit
0.02(10)
CCDC-837172
–
–
–
–
CCDC-837173
CCDC-837174
CCDC-837175
CCDC-837176
Z. Anorg. Allg. Chem. 2011, 1889–1894
© 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
www.zaac.wiley-vch.de
1893

D. Hauenstein, A. Hagenbach, U. Abram
ARTICLE
[2] U. Abram, R. Münze, J. Hartung, L. Beyer, R. Kirmse, K. Köhler,
J. Stach, H. Behm, P. T. Beurskens, Inorg. Chem. 1989, 28, 834.
[3] U. Abram, B. Schmidt-Brücken, S. Ritter, Polyhedron 1999, 18,
831.
[4] U. Abram, M. Braun, S. Abram, R. Kirmse, A. Voigt, J. Chem.
Soc. Dalton Trans. 1998, 231.
b) [ReOCl3(PPh3)2] (79 mg, 0.1 mmol) was suspended in CH2Cl2
(5 mL) and HL2 (54 mg, 0.1 mmol) was added whilst stirring. After a
stirring period of 1 h, a clear red solution was formed, which was
reduced in volume giving a red precipitate of [ReOCl(L2a)]. Yield:
37 mg (64%).
[5] S. Ritter, U. Abram, Inorg. Chim. Acta 1994, 215, 159.
[6] H. H. Nguyen, J. Grewe, J. Schroer, B. Kuhn, U. Abram, Inorg.
Chem. 2008, 47, 5136.
[7] H. H. Nguyen, U. Abram, Polyhedron 2009, 28, 3945.
[8] J. Schroer, U. Abram, Polyhedron 2009, 28, 2277.
[9] H. H. Nguyen, J. J. Jegathesh, P. I. da S. Maia, V. M. Deflon, R.
Gust, S. Bergemann, U. Abram, Inorg. Chem. 2009, 48, 9356.
[10] H. H. Nguyen, K. Hazin, U. Abram, Eur. J. Inorg. Chem. 2011,
78.
Elemental analysis. Calcd. for C18H19ClN3OReS2: C, 37.26; H, 3.47;
N, 7.24; S, 11.05%. Found: C, 38.72; H, 2.04; N, 7.10; S, 10.98%. IR:
2974 (w); 1539 (s); 1458 (m); 1335 (m); 1312 (m); 1223 (m); 976 (m);
1
748 (m) cm–1. H NMR (CDCl3): δ = 1.35 (dd, 6 H, CH3); 3.65 (m,
1 H, CH2); 3.68 (m, 1 H, CH2); 4.14 (m, 1 H, CH2); 4.49 (m, 1 H,
CH2); 6.70–7.69 ppm (m, 9 H, CHarom.).
[11] H. H. Nguyen, V. M. Deflon, U. Abram, Eur. J. Inorg. Chem.
2009, 3179.
[12] L. Beyer, R. Widera, Tetrahedron Lett. 1982, 23, 1881.
[13] L. Beyer, J. Hartung, R. Widera, Tetrahedron 1984, 40, 405.
[14] R. Köhler, L. Beyer, A. Hantschmann, E. Hoyer, Z. Chem. 1990,
30, 102.
Synthesis of [ReO(CN)(L2a)]
[ReOCl(L2a)] (30 mg, 0.05 mmol) was added to a suspension of KCN
(10 mg, 0.115 mmol) in a mixture of methanol (2 mL) and CH2Cl2
(1 mL). The mixture was stirred at room temperature for 1 h. The re-
sulting red precipitate was filtered off, subsequently washed with
water, methanol and ethyl ether, and recrystallised from a CH2Cl2/
methanol mixture. Yield: 24 mg (88%). Elemental analysis. Calcd. for
C19H19N4OReS2: C, 39.98; H, 3.53; N, 9.82; S, 11.24%. Found: C,
39.63; H, 2.97; N, 8.70; S, 11.18%. IR: 2208 (s), 1701 (m); 1543 (s);
1458 (m); 1339 (w); 1223 (m); 984 (m); 752 (m) cm–1. 1H NMR
(CDCl3): δ = 1.15 (dd, 6 H, CH3); 3.59 (m, 1 H, CH2); 3.79 (m, 1 H,
CH2); 3.98 (m, 1 H, CH2); 4.28 (m, 1 H, CH2); 7.19–8.07 ppm (m, 9
H, CHarom.).
[15] R. Köhler, Thesis, Univ. Leipzig, 1989.
[16] S. Bender, E. Hoyer, G. Zahn, Z. Anorg. Allg. Chem. 1999, 625,
1489.
[17] K. Brandenburg, H. Putz, DIAMOND – a program for the repre-
sentation of crystal structures, vers. 3.2, Crystal Impact, Bonn,
Germany, 2011.
[18] H. H. Nguyen, U. Abram, Inorg. Chem. 2008, 47, 5136.
[19] U. Abram, Rhenium, in: Comprehensive Coordination Chemistry
II (Eds.: J. A. McCleverty, T. J. Mayer), Vol. 5, Elsevier: Amster-
dam, The Netherlands, 2003, p. 271.
[20] R. Alberto, Technetium, in: Comprehensive Coordination Chem-
istry II (Eds.: J. A. McCleverty, T. J. Mayer), Vol. 5, Elsevier:
Amsterdam, The Netherlands, 2003, p. 127.
X-ray Crystallography
[21] B. Kuhn, U. Abram, Z. Anorg. Allg. Chem. 2011, 637, 242.
[22] A. W. Addison, T. N. Rao, J. Reedijk, J. van Rijn, G. C. Ver-
schoor, J. Chem. Soc. Dalton Trans. 1984, 1349.
[23] H. H. Nguyen, T. N. Trieu, U. Abram, Z. Anorg. Allg. Chem.
2011, 637, 1330.
[24] R. Alberto, R. Schibli, A. Egli, P. A. Schubiger, W. A. Herrmann,
G. Artus, U. Abram, T. A. Kaden, J. Organomet. Chem. 1995,
492, 217.
[25] F. A. Cotton, A. Davison, V. W. Day, L. D. Gage, H. S. Trop, In-
org. Chem. 1979, 18, 3024.
[26] N. P. Johnson, C. J. L. Lock, G. Wilkinson, Inorg. Synth. 1967, 9,
145.
The X-ray diffraction data were collected with a STOE IPDS dif-
fractometer with Mo-Kα radiation. The structures were solved by the
Patterson method using SHELXS-97.[27] Subsequent Fourier-differ-
ence map analyses yielded the positions of the non-hydrogen atoms.
Refinement was performed using SHELXL-97.[27] The positions of
hydrogen atoms were calculated for idealised positions and treated
with the “riding model” option of SHELXL-97. Crystal data and more
details of the data collections and refinements are contained in Table 4.
Additional information on the structure determinations have been de-
posited at the Cambridge Crystallographic Data Centre.
[27] G. M. Sheldrick, SHELXS-97 and SHELXL-97, Programs for the
Solution and Refinement of Crystal Structures, University of
Göttingen, Germany, 1997.
References
[1] J. R. Dilworth, J. S. Lewis, J. R. Miller, Y. Zheng, Polyhedron
1993, 12, 221.
Received: August 5, 2011
Published Online: September 27, 2011
1894
www.zaac.wiley-vch.de
© 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Z. Anorg. Allg. Chem. 2011, 1889–1894