Re V N and Tc V N complexes with a novel tetradentate hybrid benzamidine/thiosemicarbazone ligand Hung Huy Nguyena,⁎ , Juan Daniel Castillo Gomezb, Ulrich Abramb,⁎ a Department of Chemis
Trang 1Re V N and Tc V N complexes with a novel tetradentate hybrid benzamidine/
thiosemicarbazone ligand
Hung Huy Nguyena,⁎ , Juan Daniel Castillo Gomezb, Ulrich Abramb,⁎
a
Department of Chemistry, Hanoi University of Science, 19 Le Thanh Tong, Hanoi, Viet Nam
b Freie Universität Berlin, Institute of Chemistry and Biochemistry, Fabeckstr 34-36, D-14195 Berlin, Germany
a b s t r a c t
a r t i c l e i n f o
Article history:
Received 28 August 2012
Accepted 3 October 2012
Available online 12 October 2012
Keywords:
Rhenium
Technetium
Thiourea derivatives
Thiosemicarbazones
Cyclization
X-ray structure
N-(diethylthiocarbamoyl)benzimidoyl chloride reacts with o-aminoacetophenone 4-methylthiosemicarbazone under formation of a novel N2S2benzamidine/thiosemicarbazone ligand (H2L) The reaction of H2L with [ReNCl2(PPh3)2] yields a red complex of the composition [ReN(L)] The molecular structure of [ReN(L)] reveals
a square-pyramidal environment around the Re atom, in which the organic ligand occupies all four positions
of the equatorial plane The reaction of H2L with [TcNCl2(PPh3)2] results in a mixture of [TcN(L)] and a side-product of the composition [TcN(PPh3){Et2NC(S)NH}(L′)] (L′ = 1,10b-dimethyl-5-phenyl-1,10b-dihydro-[1,2,4]triazolo[1,5-c]quinazoline-2-thiolate) The formation of diethylthiourea and HL′ is the result
of a metal-driven decomposition of H2L followed by cyclization
© 2012 Elsevier B.V All rights reserved
Tri-, tetra- or poly-dentate ligands are of particular interest for
medical or biological applications (including nuclear medical imaging
or therapeutic procedures), since they form stable or kinetically inert
complexes Previous studies have shown that mono- and bidentate
li-gand systems may suffer from insufficient in vivo stability due to
rapid ligand exchange reactions with plasma components[1–7]
For common technetium(V) and rhenium(V) cores, ligands with
‘me-dium’ and ‘soft’ donor atoms are particularly recommended[1–9] Thus,
chelators with a mixed sulfur and nitrogen donor sphere should be very
suitable and some of them have found application in routine nuclear
medical procedures [10–12] N-[N′,N′-(dialkylamino(thiocarbonyl)]
benzimidoyl chlorides (1) readily react with ammonia or primary
amines under formation of benzamidine-type compounds[13,14]
By the use of thiosemicarbazide in similar reactions, we were
recent-ly successful in the synthesis of a series of tridentate benzamidine/
thiosemicarbazide ligands[15,16] These novel ligands form stable
complexes with both oxo- and nitridorhenium(V)/technetium(V)
cores[17,18] Additionally, the organic ligands, their oxorhenium(V)
complexes and their gold(III) complexes show promising
cytotoxic-ity on breast cancer cell lines[18,19]
In a recent communication, we published ReO and TcO complexes with a novel class of tetradentate thiocarbamoylbenzamidine ligands derived from o-phenylenediamine (2)[20] It could be shown that the chelates are perfectly stable and resist ongoing ligand exchange This encouraged us to develop novel tetradentate ligands, which pos-sess different coordination sites Such hybrid ligands may provide moreflexibility for the coordination of various metal ions
Here, we present the synthesis of a tetradentate thiosemicarbazone/ thiocarbamoylbenzamidine hybrid ligand (H2L) and its reactions with [ReNCl2(PPh3)2] and [TcNCl2(PPh3)2] together with the structures of their products
N-(diethylthiocarbamoyl)benzimidoyl chloride 1a readily reacts with o-aminoacetophenone 4-methylthiosemicarbazone in the pres-ence of a supporting base like Et3N under formation of the ligand
H2L in high yields In order to avoid undesired side-reactions, dry EtOH was used instead of acetone for the preparation of the ligand
H2L[21] The progress of the reaction can easily be controlled by thin-layer chromatography, and the ligand H2L precipitates directly from the reaction mixture as a pure yellow powder (Scheme 1) The IR spectrum of H2L is characterized by broad bands of theνN\H vi-brations in the region around 3200 cm−1and sharp, intense absorptions
at 1717 cm−1and 1686 cm−1which are assigned to theνC_Nstretches The1H NMR spectrum of the uncoordinated ligand shows three different
N\H resonances at 7.64 ppm, 8.41 ppm and 12.62 ppm Two sets of well separated signals corresponding to the resonance of two ethyl groups of the NEt2moiety are observed in the1H NMR spectrum of H2L This indi-cates that they are magnetically nonequivalent, which is due to a hindered rotation around the C-NEt2bond, which is common for many uncoordinated thiocarbamoylbenzamidines as well as for
⁎ Corresponding authors.
E-mail addresses: nguyenhunghuy@hus.edu.vn (H.H Nguyen),
abram@chemie.fu-berlin.de (U Abram).
1387-7003/$ – see front matter © 2012 Elsevier B.V All rights reserved.
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Inorganic Chemistry Communications
j o u r n a l h o m e p a g e : w w w e l s e v i e r c o m / l o c a t e / i n o c h e
Trang 2their rhenium(V) or technetium(V) complexes[14–19] In contrast
to this behavior, the C\NHMe bond of the thiosemicarbazone unit
isflexible enough to give only one methyl signal at 3.08 ppm
H2L readily reacts with [ReNCl2(PPh3)2] in boiling CH2Cl2under
formation of a red solid of the composition [ReN(L)][23] The
addi-tion of a supporting base such as Et3N allows the synthesis to be
car-ried out at ambient temperature with higher yields (Scheme 2) The
product is only sparingly soluble in alcohols, but soluble in CH2Cl2
or CHCl3and can be recrystallized from a CH2Cl2/MeOH solution
The IR spectrum of [ReN(L)] reveals a moderate absorption at
3417 cm−1, which is assigned to theνN\Hstretch of the MeNH-CS group The absorption band of theνC_Nvibration is observed as a very intense peak at 1527 cm−1 This corresponds to a strong bathochromical shift of about 190 cm−1and indicates chelate for-mation with a large degree ofπ-electron delocalization within the chelate rings The1H NMR spectrum of the compound shows the ab-sence of N\H resonances of benzamidine and thiocarbazone moie-ties and a highfield shift of the signal corresponding to N\H in the CS-NHMe residue to 5.28 ppm This reflects that the organic ligand
is coordinated to Re in the form {L}2− The hindered rotation around the C\NEt2 bond results in two magnetically inequivalent ethyl groups Thus, two triplet signals of the methyl groups in the\NEt2
residue are observed in the1H NMR spectrum of [ReN(L)] measured
at room temperature However, the proton signals of the two meth-ylene groups, which should consequently be two quartets, appear as four well separated multiplet resonances at 3.58, 3.68, 4.32 and 4.40 ppm This pattern of the methylene signals has previously been rationalized by the rigid structure of the tertiary amine group, which makes the methylene protons magnetically nonequivalent with respect to their axial and equatorial positions[24]
A crystallographic study of single crystals of [ReN(L)] shows a five-coordinate rhenium(V) complex (Fig 1)[25] The rhenium atom has a distorted square-pyramidal environment with the terminal nitrido ligand in apical position The ligand {L}2− is equatorially
NH2 O
NH2 N HN HN S
N NH
N S N HN HN S
1a,Et3N,EtOH
4-methylthio-semicarbazide
H2L
Scheme 1 Synthesis of H 2 L.
[ReNCl2(PPh3)2] + H2L
N N
N S N
N HN S Re
N
CH2Cl2,Et3N -PPh3,HNEt3Cl
Scheme 2 Reaction of H 2 L with [ReNCl 2 (PPh 3 ) 2 ].
Table 1 Selected bond lengths (Å) and angles (°) in [ReN(L)] and [TcN(L)].
[ReN(L)] [TcN(L)]
M–S12 2.340(1) 2.347(2)
N1–M–S1 105.7(1) 105.2(2) N1–M–S12 110.3(1) 110.3(2) N1–M–N5 106.7(2) 107.8(2) N1–M–N9 100.9(2) 101.6(2)
73 H.H Nguyen et al / Inorganic Chemistry Communications 26 (2012) 72–76
Trang 3coordinated via its N2S2donor set The Re atom is situated 0.604(1) Å
above the basal plane toward the nitrido ligand The N1–Re–N/S angles
fall in the range between 100.9(2) and 110.3(1)° The Re\N1 bond
length of 1.668(4)Å is in the expected range for rhenium–nitrogen
tri-ple bonds[9] More bond lengths and angles are summarized inTable 1
The reaction of H2L with the analogous technetium precursor
[TcNCl2(PPh3)2] proceeds in a slightly different way[28] Besides the
main product [TcN(L)], which can be obtained as large orange-red
crys-tals, an unexpected yellow side-product is formed in moderate yields
(Scheme 3) Both compounds are sparingly soluble in MeOH and
tallize from the reaction mixture after the addition of MeOH as big
crys-tals which can be separated mechanically
IR and1H NMR spectra of [TcN(L)] mainly exhibit the same patterns
as described for the rhenium complex described above, indicating a
similar bonding situation An X-ray diffraction study confirms the
anal-ogous arrangement of the ligands[29] The technetium atom also
re-veals a distorted square-pyramidal coordination sphere with an apical
{N}3−ligand Since the molecular structures of [ReN(L)] and [TcN(L)]
are virtually identical, no extrafigure of the Tc compound is shown in
this communication Selected bond lengths and angles of the
techne-tium complex are contained inTable 1and compared to the values of
the rhenium compound The atomic labeling scheme of the rhenium
complex has also been applied for the Tc compound With the reported
structural data, [TcN(L)] resembles the main features of the structures
of the hitherto only two TcVN complexes with tetradentate N2S2ligands
[30,31]
The IR spectrum of the side-product is quite similar to that of
[ReN(L)], except that the N–H band is sharp and long-wave shifted to
3363 cm−1 However, the1H NMR spectra of the two compounds are
completely different In1H NMR spectrum of the yellow compound,
the ethyl resonances still reflect the rigid structure of the tertiary
amine nitrogen atom of the thiourea group, but the observed signals
are strongly high-field shifted Despite the fact that in the1H NMR spec-trum of [TcN(L)], the CH3-NH signal of the thiosemicarbazone moiety appears as a doublet at 3.05 ppm due to coupling with the adjacent
N–H proton, the corresponding resonance of the yellow side-product
is a singlet at 3.66 ppm and another methyl signal appears at 1.41 ppm This resonance is at an even higherfield than that in the spec-trum of the uncoordinated H2L From the1H NMR discussion, we can conclude that the main skeleton of the organic ligand‘{L}2−is not maintained in the side-product The31P NMR spectrum reveals a singlet
at 48.86 ppm and, thus, indicates the presence of a PPh3ligand in the coordination sphere of the metal
However, the structure of the compound could not be deduced unambigously from the spectroscopic methods, and an X-ray diffrac-tion study was performed also for this complex[32].Fig 2depicts an ellipsoid presentation of its molecular structure The structural study confirms the assumed decomposition of the ligand H2L during the re-action with the technetium precursor and the formation of a hetero-cyclic thiol/thione HL′ and N,N-diethylthiourea (see alsoScheme 4) The coordination environment of the technetium atom is best de-scribed as a distorted square pyramid with an apical nitrido ligand The basal plane contains three ligands: the heterocyclic thiolato li-gand {L′}−, which binds monodentate via its sulfur atom, a bidentate N,N-diethylthioureido ligand and PPh3, which is arranged in a trans position to the nitrogen donor atom The bonding situation in the li-gand {L′}− reveals the sp2hybridization of the carbon atoms C11 and C4 Although some delocalization of theπ-electron density is found in the skeleton of {L′}−, the C4–N5 and C11–N10 bond lengths
of 1.32(1) Å and 1.31(1) Å, respectively, are slightly shorter than the other carbon–nitrogen bonds and indicate more double bond charac-ter The Tc–S12 distance of 2.373(2)Å is 0.03 Å shorter than the Tc–S1 bond length Delocalization of the negative charge is also observed in the four-membered chelate ring of the N,N-diethylthioureido ligand and is reflected by the C2–N3 and C2–S1 bond lengths, which fall be-tween the values of carbon–nitrogen and carbon–sulfur single and double bonds
The solid state structure of [TcN(PPh3){Et2NC(S)NH}(L′)] contains relatively large lipophilic voids, which are notfilled by solvent mole-cules and form channel-like structures along the crystallographic c axis They are bounded by the phenyl and alkyl residues of the li-gands, which most probably avoids the stabilization of polar solvent molecules such as methanol or CH2Cl2inside these channels The formation of [TcN(PPh3){Et2NC(S)NH}(L′)] is reproducible and clearly a result of the decomposition of H2L However, it is worth men-tioning that a similar decomposition is not found in the synthesis of the analogous rhenium complex, whether under the same conditions, nor with reflux More interestingly, the technetium complex [TcN(L)] is perfectly stable, even under reflux conditions in CH2Cl2with and with-out the addition of a base Additionally, the purity of the ligand H2L was confirmed by different spectroscopic methods as well as by elemental analysis These synthetic evidences suggest that the two technetium compounds are formed independently and the decomposition of H2L only occurs during the formation of [TcN(PPh){EtNC(S)NH}(L′)]
[TcNCl2(PPh3)2] + H2L
N N
N S N N HN S Tc
N
CH2Cl2,Et3N
main product
H N S
T c PPh3
N N
N
N N N S +
side product -PPh3,HNEt3Cl
Scheme 3 Reaction of H 2 L with [TcNCl 2 (PPh 3 ) 2 ].
Fig 2 Ellipsoid representation of the molecular structure of [TcN(PPh 3 ){Et 2 NC(S)
NH}(L′)] [27] Selected bond lengths and angles are summarized in Ref [33]
Trang 4A possible mechanism is proposed inScheme 4 It is supposed that
one of the chlorido ligands of [TcNCl2(PPh3)2] isfirst exchanged by
the thiourea sulfur atom of H2L This is confirmed by a previously
published reaction pattern of [ReOCl2(PPh3)3] with a benzamidine
derived from glycine ester, in which an intermediate S-thiourea
monodentate product was successfully isolated[16] Subsequently, a
phosphine ligand can be replaced either by the N5 or the N3 donor
atoms Thefirst situation results in the formation of a benzamidine
chelate ring and consequently produces [TcN(L)] (not shown in
Scheme 4) In the second case, an intermediate cationic complex
(3) is formed, in which the positive charge is partially located in the
atom C4 This allows a nucleophilic attack with subsequent bond
cleavage and cyclization The resulting N,N-diethylthioureido ligand
remains coordinated to the technetium atom and forms the
interme-diate complex 4 The released heterocyclic thion 5 deprotonates and
replaces the chlorido ligand in 4 under formation of thefinal product
[TcN(PPh3){Et2NC(S)NH}(L′)]
In the present communication, we could show that the novel
benzamidine/thiosemicarbazone hybrid ligand forms stable
com-plexes with technetium and rhenium, but may be only partially
suit-able for applications in nuclear medical labeling procedures, since
during the reactions with common Tc compounds unexpected ligand
cleavage and cyclization reactions may occur The fact that this
be-havior is not observed with the analogous rhenium compound, puts
a serious question mark over the more or less generally accepted
opinion that model studies with rhenium compounds are sufficient
to predict the behavior of analogous technetium complexes reliably
Appendix A Supplementary material
Supplementary data to this article can be found online athttp://
dx.doi.org/10.1016/j.inoche.2012.10.004
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[17] H.H Nguyen, P.I.d.S Maia, V.M Deflon, U Abram, Inorg Chem 48 (2009) 25 [18] H.H Nguyen, J.J Jegathesh, P.I.d.S Maia, V.M Deflon, R Gust, S Bergemann, U Abram, Inorg Chem 48 (2009) 9356.
[19] P.I.d.S Maia, H.H Nguyen, D Ponader, A Hagenbach, S Bergemann, R Gust, V.M Deflon, U Abram, Inorg Chem 51 (2012) 1604.
[20] J.D Castillo Gomez, H.H Nguyen, A Hagenbach, U Abram, Polyhedron 43 (2012) 123.
[21] Synthesis of 2-aminoacetophenone-N-(4-methylthiosemicarbazone) The compound was synthesized from 2-aminoacetophenone and 4-methylthiosemicarbazone fol-lowing a literature procedure [22] Yield 70% Elemental analysis: Calcd for
C 10 H 14 N 4 S: C, 54.03; H, 6.35; N, 25.20; S, 14.42% Found: C, 54.20; H, 5.82; N, 24.39;
S, 15.65%; IR (KBr, cm−1): 3237 (w), 2955 (w), 2900 (w), 1605 (vs), 1589 (vs),
1537 (m), 1480 (m), 1267 (s), 1110 (m), 1099 (m), 991 (m), 827 (m), 774 (s), 683 (s) 1
H NMR (400 MHz, DMSO-d 6 , ppm): 2.30 (s, 3H, CH 3 ), 3.00 (s, 3H, NCH 3 ), 6.91 (t, J=7.0 Hz, 1H, C 6 H 4 ), 7.01 (d, J=7.9 Hz, 1H, C 6 H 4 ), 7.21 (t, J=7.3 Hz, 1H, C 6 H 4 ), 7.44 (d, J=6.8 Hz, 1H, C 6 H 4 ), 8.21 (s, br, 2H, NH), 10.20 (s, 1H, NH).Synthesis of
H 2 L Solid N-[(diethylamino)(thiocarbonyl)]benzimidoyl chloride (1.018 g, 4 mmol) was added to a mixture of 2-aminoacetophenone-N-(4-methylthiosemicarbazone) (889 mg, 4 mmol) and triethylamine (1.01 g, 10 mmol) in 10 mL of absolute ethanol The mixture was stirred for 1 h at 50 °C Upon cooling, H 2 L deposited as a yellow crys-talline solid, which was filtered off, washed with cold MeOH and dried in vacuum Yield: 45% (616 mg) Elemental analysis: Calcd for C 22 H 28 N 6 S 2 : C, 59.97; H, 6.40; N, 19.07; S, 14.55% Found: C, 59.45; H, 6.02; N, 19.86; S, 15.02%; IR (KBr, cm−1): 3194 (m), 3051 (w), 2974 (m), 2928 (m), 2827 (w), 1717 (s), 1686 (s), 1608 (m), 1574 (s), 1539 (s), 1419 (s), 1335 (m), 1269 (s), 1246 (s), 1180 (m), 1134 (s), 1084 (m),
1026 (m), 898 (m), 759 (m), 694 (m) 1
H NMR (400 MHz, CDCl 3 , ppm): 1.17 (t, J=7.1 Hz, 3H, CH 3 ), 1.22 (t, J=7.1 Hz, 3H, CH 3 ), 1.86 (s, 3H, CH 3 ), 3.08 (s, 3H, NCH 3 ), 3.75 (q, J=7.1 Hz, 2H, NCH 2 ), 3.88 (q, J=7.1 Hz, 2H, NCH 2 ), 7.07 (t, J=7.1 Hz, 2H, Ph), 7.13–7.19 (m, 4H, Ph+C 6 H 4 ), 7.26 (m, 3H, Ph+C 6 H 4 ), 7.64 (s, 1H, NH), 8.41 (s, 1H, NH), 12.63 (s, 1H, NH) 13 C NMR (400 MHz, CDCl 3 , ppm): 11.99 (CH 2 CH 3 ), 13.53 (CH 2 CH 3 ), 15.55 (N_CCH 3 ), 31.40 (NCH 3 ), 44.92 (NCH 2 ), 45.63 (NCH 2 ), 125.45, 126.21, 128.08, 129.03, 129.11, 129.44, 130.49, 132.31, 135.28, 136.67 (aromatic), 145.52 (MeC_N), 159.77 (C_N), 178.36 (C_S), 184.95 (C_S).
[22] D.X West, A.A Nassar, F.A El-Saied, M.I Ayad, Trans Met Chem 24 (1999) 617 [23] Synthesis of [ReN(L)] A mixture of H 2 L (44 mg, 0.1 mmol), [ReNCl 2 (PPh 3 ) 2 ] (80 mg, 0.1 mmol) and three drops of Et 3 N in CH 2 Cl 2 (5 mL) was stirred for 2 h at room tem-perature The solvent was removed to dryness and the residue was carefully washed with MeOH, dried in vacuum and redissolved in a CH 2 Cl 2 /MeOH (1:1) mixture Slow evaporation of the solvent gave red crystals Yield 75% (48 mg) Elemental analysis: Calcd for C 22 H 26 N 7 S 2 Re: C, 41.36; H, 4.10; N, 15.35; S, 10.04% Found: C, 41.11; H, 4.19; N, 14.95; S, 10.13%; IR (KBr, cm−1): 3417 (m), 3050 (w), 2970 (m), 2924 (m), 1527 (vs), 1440 (m), 1342 (s), 1257 (m), 1219 (m), 1149 (w), 1072 (m),
1033 (w), 810 (w), 764 (m), 671 (w) 1
H NMR (400 MHz, CDCl 3 , ppm): 1.32 (t, J=7.2 Hz, 3H, CH 3 ), 1.36 (t, J=7.2 Hz, 3H, CH 3 ), 3.11 (d, J=5.0, 3H, NCH 3 ), 3.13 (s, 3H, N=C-CH 3 ), 3.58 (m, 1H, NCH 2 ), 3.68 (m, 1H, NCH 2 ), 4.32 (m, 1H, NCH 2 ), 4.40 (m, 1H, NCH 2 ), 5.28 (s, br, NH), 6.78 (d, J=8.0 Hz, 1H, C 6 H 4 ), 6.93 (t, J=7.6 Hz, 1H, C 6 H 4 ), 7.00 (t, J=7.7 Hz, 1H, C 6 H 4 ), 7.10 (m, 3H, Ph), 7.27 (d, J=7.2 Hz, 2H, Ph), 7.75 (d, J=7.9 Hz, 1H, C 6 H 4 ) FAB +
MS (m/z): 639, 90%, [M+H] + ; 567, 12%, [M–NEt 2 +H] +
[24] H.H Nguyen, V.M Deflon, U Abram, Eur J Inorg Chem 21 (2009) 3179 [25] Crystal data for [ReN(L)]: triclinic, space group P(−)1, a=8.598(1), b=10.974(1), c=13.669(1)Å, α=66.64(1), β=79.86(1), γ=77.99(1), V=1151.8(2)Å 3 , Z=2 STOE-IPDS, Mo Kα radiation (λ=0.71073 Å), T=200 K, 21,421 reflections mea-sured, 5839 independent, 289 parameters, μ=5.482 mm −1 , absorption correction: integration, T min =0.2036, T max =0.3541 Structure solution and refinement: SHELXS-97, SHELXL-97 [26] , R1=0.0357, wR2=0.0978, GooF=1.157, CCDC de-posit number: CCDC-898325.
[26] G.M Sheldrick, SHELXS-97 and SHELXS-97 — a Programme Package for the Solution and Refinement of Crystal Structures, University of Göttingen, Germany, 1997
[27] K Brandenburg, H Putz, Diamond — a Crystal and Molecular Structure Visualisa-tion Software, , 2005 Bonn, Germany.
[28] Synthesis of [TcN(L)] and [TcN(PPh 3 ){Et 2 NC(S)NH}(L′)] Solid [TcNCl 2 (PPh 3 ) 2 ]
3 NH
5 N
S
Et2N
N NH NH
Cl PPh3
3 N
N N
N NH
S Et3 N
H
S Tc Cl PPh3
N N
H
S Tc PPh3
N N
N
N N N S +
+
Cl
-4 3
5
Scheme 4 Proposed formation of [TcN(PPh 3 ){Et 2 NC(S)NH}(L′)].
75 H.H Nguyen et al / Inorganic Chemistry Communications 26 (2012) 72–76
Trang 5al 15 min at room temperature This resulted in a complete dissolution of
[TcNCl 2 (PPh 3 ) 2 ] and the formation of a red solution The solvent was removed
under vacuum, and the residue was recrystallized from a CH 2 Cl 2 /MeOH mixture
to obtain large orange-red crystals of [TcN(L)] and yellow needles of [TcN(PPh 3 )
{Et 2 NC(S)NH}((L′)] which were separated mechanically.Data for [TcN(L)]: Yield
40% (21 mg) Elemental analysis: Calcd for C 22 H 26 N 7 S 2 Tc: Tc, 17.9% Found: Tc,
18.1%; IR (KBr, cm−1): 3418 (m), 3051 (w), 2970 (m), 2924 (m), 1547 (s),
1528 (vs), 1477 (m), 1431 (m), 1357m), 1338 (m), 1261 (m), 1226 (m), 1145
(w), 1091 (w), 1064 (m), 1037 (w), 810 (w), 756 (m), 675 (w) 1
H NMR (400 MHz, CDCl 3 , ppm): 1.34 (m, 6H, CH 3 ), 2.97 (s, 3H, N_C-CH 3 ), 3.05
(d, J = 4.8, 3H, NCH 3 ), 3.54 (m, 1H, NCH 2 ), 3.66 (m, 1H, NCH 2 ), 4.19 (m, 1H,
NCH 2 ), 4.26 (m, 1H, NCH 2 ), 5.15 (s, br, NH), 6.67 (d, J = 7.9 Hz, 1H, C 6 H 4 ), 6.89
(t, J = 7.4 Hz, 1H, C 6 H 4 ), 6.95 (t, J = 7.6 Hz, 1H, C 6 H 4 ), 7.10(m, 3H, Ph), 7.28
(d, J = 7.1 Hz, 2H, Ph), 7.66 (d, J = 7.9 Hz, 1H, C 6 H 4 ).Data for [TcN(PPh 3 )
{Et 2 NC(S)NH}(L′)]: Yield 14% (12 mg) Elemental analysis: Calcd for C 40 H 41 N
7-PS 2 Tc: Tc, 12.2% Found: Tc, 12.4% IR (KBr, cm −1 ): 3363 (m), 3044 (w), 2978
(m), 2931 (m), 1558 (vs), 1473 (m), 1434 (m), 1307 (s), 1269 (s), 1238 (s),
1184 (m), 1149 (w), 1095 (m), 1068 (m), 860 (w), 740 (s), 694 (s), 528 (m),
497 (m) 1 H NMR (400 MHz, CDCl 3 , ppm): 0.49 (t, J = 7.1 Hz, 3H, CH 3 ), 0.88
(t, J = 7.1 Hz, 3H, CH 3 ), 1.41 (s, 3H, N=C\CH 3 ), 2.25 (m, 1H, NCH 2 ), 2.39
(m, 1H, NCH 2 ), 3.12 (m, 2H, NCH 2 ), 3.66 (s, 3H, NCH 3 ), 5.76 (s, br, 1H, NH),
7.32 (m, 17H, Ph), 7.60 (m, 6H, Ph), 8.05 (d, J = 7.7 Hz, 1H, Ph) 31 P NMR
(400 MHz, CDCl 3 , ppm): 48.86 (s).
c=13.672(1) Å, α=66.82(1), β=80.34(1), γ=78.64(1), V=1154.0(2)Å , Z=2 STOE-IPDS, Mo Kα radiation (λ=0.71073 Å), T=200 K, 11967 reflections mea-sured, 6149 independent, 290 parameters, μ=0.830 mm −1 , absorption correction: none Structure solution and refinement: SHELXS-97, SHELXL-97 [26] , R1=0.0580, wR2=0.0998, GooF=0.902, CCDC deposit number: CCDC-898326.
[30] F Tisato, U Mazzi, G Bandoli, G Cros, M.-H Darbieu, Y Coulais, R Guiraud,
J Chem Soc., Dalton Trans (1991) 1301.
[31] G Cros, H.B Tahar, D de Montauzon, A Gleizes, Y Coulais, R Guiraud, E Bellande,
R Pasqualini, Inorg Chim Acta 227 (1994) 25.
[32] Crystal data for [TcN(PPh 3 ){Et 2 NC(S)NH}(L′)]×H 2 O: triclinic, space group P(−)1,
a = 11.622(3), b = 13.182(3), c = 14.620(4) Å, α=92.45(2), β=92.73(2), γ=110.76(2), V=2087.5(9) Å 3
, Z = 2 STOE-IPDS, Mo Kα radiation (λ=0.71073 Å), T=200 K, 21,440 reflections measured, 11,079 independent,
465 parameters, μ=0.522 mm −1 , absorption correction: none Structure solu-tion and refinement: SHELXS-97, SHELXL-97 [26] , R1 = 0.074, wR2 = 0.1682, GooF = 0.865, CCDC deposit number: CCDC-898327.
[33] Selected bond lengths and angles in [TcN(PPh 3 ){Et 2 NC(S)NH}(L′)]: Tc–N1 1.617(8), Tc–S1 2.403(3), Tc–N3 2.097(7), Tc–S12 2.373(2), Tc–P 2.405(2), S1– C2 1.767, S12–C11 1.742(9), C2–N3 1.32(1), C2–N6 1.33(1), C4–N5 1.33(1), C4–N9 1.34(1), N10–C11 1.32(1), C11–N13 1.39(1), C7–N13 1.48(1), C7–N9 1.47(1); N1–Tc–S1 111.6(3), N1–Tc–N3 107.1(4), N1–Tc–S12 111.6, N1–Tc–P 94.9(3), N3–Tc–P 156.4(2), S1–Tc–S12 136.2(1).